Publications by authors named "Maria C Rodriguez"

37 Publications

Development of a DIVA ELISA for diagnosis of Aujeszky's disease using recombinant gE fused to thioredoxin as antigen.

Vet J 2020 Mar 5;257:105448. Epub 2020 Mar 5.

Departamento de Medicina Veterinaria, Universidade Federal Rural de Pernambuco, Recife, PE, 52171-900, Brazil; Departamento de Genetica, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil. Electronic address:

The major control methods for Aujeszky's Disease (AD) involve SHV1 gE gene-deleted vaccines and ELISA for detection of specific gE antibodies in infected animals, distinguishing infected animals from vaccinated animals (DIVA). This work aimed to develop a DIVA ELISA recombinant gE (gErec) for AD diagnosis using recombinant gE fused to thioredoxin protein. The analytical sensitivity and specificity were assessed with World Organisation for Animal Health (OIE) AD serum and sera from specific pathogen free (SPF), vaccinated SPF and AD-vaccinated SPF animals. The OIE serum reacted up to the recommended limit of detection and the other sera presented negative results. The cut-off point, diagnostic sensitivity and diagnostic specificity were determined by receiver operating curve analysis. This cut-off value corresponded to a diagnostic sensitivity of 97.60% and diagnostic specificity of 96.42%. Furthermore, two other cut-off points were chosen to discuss the ELISAgErec as a screening test in AD-endemic and free areas.
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http://dx.doi.org/10.1016/j.tvjl.2020.105448DOI Listing
March 2020

Development and Application of Interactive, Culturally Specific Strategies for the Consumption of High-fiber Foods in Puerto Rican Adolescents.

Ecol Food Nutr 2020 Nov 20;59(6):639-655. Epub 2020 May 20.

Department of Agricultural Economics and Rural Sociology, College of Agricultural Sciences, University of Puerto Rico , Mayagüez, Puerto Rico.

Healthy eating practices in the adolescents can prevent the development of obesity and other chronic diseases in the adulthood. The consumption of fruits, vegetables, and whole grains in Puerto Rican adolescents is low and might be contributing to the high prevalence of food-related chronic diseases, such as obesity in this group. The purpose of the study was to develop and apply interactive methods and strategies that help adolescents make healthy food choices. Over time, healthy food choices can delay or prevent food-related chronic diseases in the adulthood. Information from the focus groups helped to develop nutrition education materials that were age-culturally specific. Following nutrition education, the consumption of foods high in dietary fiber such as fruits, vegetables, and whole-grain cereals improved significantly in Puerto Rican adolescents. A modified socioecological model for dietary fiber-rich foods consumption in Puerto Rican adolescents, demonstrated that effective nutrition education strategies reduced the barriers to dietary fiber-rich foods consumption on the adolescents, their parents and the community promoting healthy eating choices of fruits, vegetables, and whole-grain cereals, to prevent food-related chronic diseases in the adulthood.
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http://dx.doi.org/10.1080/03670244.2020.1763980DOI Listing
November 2020

Design and validation of an immuno-PCR assay for IFN-α2b quantification in human plasma.

Bioanalysis 2019 Dec 14;11(23):2175-2188. Epub 2019 Nov 14.

UNL, CONICET, School of Biochemistry & Biological Sciences, Biotechnological Center of Litoral, Ciudad Universitaria, Ruta Nacional 168, Km 472.4, CC 242, S3000ZAA, Santa Fe, Argentina.

Nowadays, IFN-α is considered a promising therapeutic target for systemic lupus erythematosus. An immuno-PCR (iPCR) was developed to quantify low amounts of IFN-α in human plasma followed by a deep analysis of the methodologic robustness throughout quality by design approach. An accurate, sensitive, selective and versatile iPCR was validated. The critical iPCR procedural steps were identified, applying a Plackett-Burman design. Also, this assay demonstrated an outstanding LOD of 0.3 pg/ml. A significant aspect relies on its high versatility to detect and quantify other cytokines in human plasma as the appropriate biotinylated antibody is employed. This reliable iPCR assay can be clinically used as an alternative method for quantitating and detecting low IFN-α2b concentrations in human plasma samples.
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http://dx.doi.org/10.4155/bio-2019-0225DOI Listing
December 2019

Paramylon and synthesis of its ionic derivatives: Applications as pharmaceutical tablet disintegrants and as colloid flocculants.

Carbohydr Res 2019 Oct 16;484:107779. Epub 2019 Aug 16.

Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Centro de Investigación en Hidratos de Carbono (CIHIDECAR), Ciudad Universitaria, 1428EGA, Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Ciudad Universitaria-Pabellón 2, 1428EGA, Buenos Aires, Argentina. Electronic address:

Paramylon, a high molecular weight polysaccharide, is a linear and unbranched (1 → 3)-β-d-glucan. Despite its numerous biological benefits, the poor aqueous solubility of crystalline paramylon is a drawback that has hampered some of its applications. In an effort to make this biomaterial amenable to practical uses, cationic and anionic paramylon derivatives were obtained. The degrees of substitution of both products were determined. The products were characterized by FT-IR spectrocopy, ESI mass spectrometry, H, C and H-C NMR and SEM microscopy. These techniques confirmed the success of the substitution reactions. H NMR analysis was used to develop alternative methods for an approximate estimation of the degree of substitution. H-C HSQC NMR spectra were assigned for both derivatives. New applications of native, cationic and anionic paramylon were found. Native paramylon showed similar performance as pharmaceutical tablet disintegrant than sodium croscarmellose. Cationic paramylon behavior as colloid flocculant was comparable with commercial cationic polyacrylamides. The anionic derivative could eventually be used in the formulation of matrix controlled release systems or as a suspending agent.
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http://dx.doi.org/10.1016/j.carres.2019.107779DOI Listing
October 2019

Changes in the physico-chemical properties of the xanthan produced by Xanthomonas citri subsp. citri in grapefruit leaf extract.

Glycobiology 2019 03;29(3):269-278

Instituto de Ciencia y Tecnología Dr. César Milstein, Fundación Pablo Cassará, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Saladillo 2468 (C1440FFX), Ciudad de Buenos Aires, Argentina.

Xanthan is a virulence factor produced by Xanthomonas spp. We previously demonstrated that this exopolysaccharide is not only essential for pathogenicity by contributing with bacterial survival but also its pyruvate substituents interfere with some plant defense responses. Deepening our studies about xanthan properties and structure, the aim of this work was to analyze the characteristics of xanthan produced by Xanthomonas in different culture media. We analyzed the xanthan produced by Xanthomonas citri subsp. citri (Xcc) in leaf extracts from grapefruit (a susceptible host of this bacterium) and compared it with the xanthan produced in a synthetic culture medium. We found that the xanthan produced in the grapefruit extract (Xan-GLE) presented shorter and more disordered molecules than xanthan produced in the synthetic medium (Xan-PYM). Besides, Xan-GLE resulted less viscous than Xan-PYM. The disordered molecular conformation of Xan-GLE could be attributed to its higher pyruvilation degree and lower acetylation degree compared with those detected in Xan-PYM. Meanwhile, the difference in the viscosity of both xanthans could be due to their molecules length. Finally, we cultured Xcc in the presence of the Xan-GLE or Xan-PYM and observed the formation of biofilm-like structures in both cases. We found significant differences in biofilm architecture between the two conditions, being the biofilm produced in presence of Xan-GLE similar to that formed in canker lesions developed in lemon plant leaves. Together, these results show how xanthan structure and properties changed when Xcc grew in a natural substrate and can contribute to better understand the biological role of xanthan.
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http://dx.doi.org/10.1093/glycob/cwy114DOI Listing
March 2019

A Qualitative Study of Puerto Rican Parent and ChildPerceptions Regarding Eating Patterns.

J Nutr Educ Behav 2019 05 1;51(5):608-615. Epub 2018 Dec 1.

Department of Agricultural Education, College of Agricultural Sciences, University of Puerto Rico, Mayagüez Campus, Mayagüez, Puerto Rico.

Objective: To identify barriers that prevent healthy eating practices in Puerto Rican early adolescents (EAs).

Design: Qualitative data collected via focus groups. A total of 7 focus groups were conducted: 5 with EAs and 2 with parents and caregivers (PCs).

Setting: Urban and rural Puerto Rico.

Participants: Early adolescents aged 12-14years (n = 52) and PCs (n = 17).

Phenomenon Of Interest: Factors that prevent healthy eating behavior in EAs in Puerto Rico.

Analysis: Verbatim transcripts from focus group interviews were coded for concept frequency, extension, and content analysis.

Results: The 3 main factors that influenced participants' eating habits, according to EAs' and PCs' answers, were stores that sold less healthful foods on or near school and the community, parental influence in the development of unhealthy eating habits, and the low cost of unhealthy foods.

Conclusions And Implications: When EAs chose what to eat, primary food choices were based on taste preferences, physical access, economic cost, and influence of PCs, whereas health effects had little consideration. Nutrition education programs have to meet taste preferences and provide eating options that are affordable, accessible, and easy to prepare to achieve healthy food practices among EAs.
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http://dx.doi.org/10.1016/j.jneb.2018.10.002DOI Listing
May 2019

Targeting cancer-specific glycans by cyclic peptide lectinomimics.

Amino Acids 2017 Nov 11;49(11):1867-1883. Epub 2017 Sep 11.

Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science, Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33431, USA.

The transformation from normal to malignant phenotype in human cancers is associated with aberrant cell-surface glycosylation. Thus, targeting glycosylation changes in cancer is likely to provide not only better insight into the roles of carbohydrates in biological systems, but also facilitate the development of new molecular probes for bioanalytical and biomedical applications. In the reported study, we have synthesized lectinomimics based on odorranalectin 1; the smallest lectin-like cyclic peptide isolated from the frog Odorrana grahami skin, and assessed the ability of these peptides to bind specific carbohydrates on molecular and cellular levels. In addition, we have shown that the disulfide bond found in 1 can be replaced with a lactam bridge. However, the orientation of the lactam bridge, peptides 2 and 3, influenced cyclic peptide's conformation and thus these peptides' ability to bind carbohydrates. Naturally occurring 1 and its analog 3 that adopt similar conformation in water bind preferentially L-fucose, and to a lesser degree D-galactose and N-acetyl-D-galactosamine, typically found within the mucin O-glycan core structures. In cell-based assays, peptides 1 and 3 showed a similar binding profile to Aleuria aurantia lectin and these two peptides inhibited the migration of metastatic breast cancer cell lines in a Transwell assay. Altogether, the reported data demonstrate the feasibility of designing lectinomimics based on cyclic peptides.
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http://dx.doi.org/10.1007/s00726-017-2485-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5693629PMC
November 2017

TMV induces RNA decay pathways to modulate gene silencing and disease symptoms.

Plant J 2017 01 24;89(1):73-84. Epub 2016 Nov 24.

Instituto de Biotecnología, CICVyA, INTA, Hurlingham, Argentina.

RNA decay pathways comprise a combination of RNA degradation mechanisms that are implicated in gene expression, development and defense responses in eukaryotes. These mechanisms are known as the RNA Quality Control or RQC pathways. In plants, another important RNA degradation mechanism is the post-transcriptional gene silencing (PTGS) mediated by small RNAs (siRNAs). Notably, the RQC pathway antagonizes PTGS by preventing the entry of dysfunctional mRNAs into the silencing pathway to avoid global degradation of mRNA by siRNAs. Viral transcripts must evade RNA degrading mechanisms, thus viruses encode PTGS suppressor proteins to counteract viral RNA silencing. Here, we demonstrate that tobacco plants infected with TMV and transgenic lines expressing TMV MP and CP (coat protein) proteins (which are not linked to the suppression of silencing) display increased transcriptional levels of RNA decay genes. These plants also showed accumulation of cytoplasmic RNA granules with altered structure, increased rates of RNA decay for transgenes and defective transgene PTGS amplification. Furthermore, knockdown of RRP41 or RRP43 RNA exosome components led to lower levels of TMV accumulation with milder symptoms after infection, several developmental defects and miRNA deregulation. Thus, we propose that TMV proteins induce RNA decay pathways (in particular exosome components) to impair antiviral PTGS and this defensive mechanism would constitute an additional counter-defense strategy that lead to disease symptoms.
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http://dx.doi.org/10.1111/tpj.13323DOI Listing
January 2017

An antibody against an Anopheles albimanus midgut myosin reduces Plasmodium berghei oocyst development.

Parasit Vectors 2016 05 10;9(1):274. Epub 2016 May 10.

Center of Research on Infectious Diseases, National Institute of Public Health, Av. Universidad 655, Col. Santa María Ahuacatitlán, Cuernavaca, Morelos, C. P. 62508, Mexico.

Background: Malaria parasites are transmitted by Anopheles mosquitoes. Although several studies have identified mosquito midgut surface proteins that are putatively important for Plasmodium ookinete invasion, only a few have characterized these protein targets and demonstrated transmission-blocking activity. Molecular information about these proteins is essential for the development of transmission-blocking vaccines (TBV). The aim of the present study was to test three monoclonal antibodies (mAbs), A-140, A-78 and A-10, for their ability to recognize antigens and block oocyst infection of the midgut of Anopheles albimanus, a major malaria vector in Latin America.

Method: Western-blot of mAbs on antigens from midgut brush border membrane vesicles was used to select antibodies. Three mAbs were tested by membrane feeding assays to evaluate their potential transmission-blocking activity against Plasmodium berghei. The cognate antigens recognized by mAbs with oocyst-reducing activity were determined by immunoprecipitation followed by liquid chromatography tandem mass spectrometry.

Results: Only one mAb, A-140, significantly reduced oocyst infection intensity. Hence, its probable protein target in the Anopheles albimanus midgut was identified and characterized. It recognized three high-molecular mass proteins from a midgut brush border microvilli vesicle preparation. Chemical deglycosylation assays confirmed the peptide nature of the epitope recognized by mAb A-140. Immunoprecipitation followed by proteomic identification with tandem mass spectrometry revealed five proteins, presumably extracted together as a complex. Of these, AALB007909 had the highest mascot score and corresponds to a protein with a myosin head motor domain, indicating that the target of mAb A-140 is probably myosin located on the microvilli of the mosquito midgut.

Conclusion: These results provide support for the participation of myosin in mosquito midgut invasion by Plasmodium ookinetes. The potential inclusion of this protein in the design of new multivalent vaccine strategies for blocking Plasmodium transmission is discussed.
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http://dx.doi.org/10.1186/s13071-016-1548-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863318PMC
May 2016

A Comprehensive Proteomic Study of the Skin Secretions of the Frog Lithobates spectabilis.

Protein Pept Lett 2016 ;23(7):597-611

Proteomics Laboratory, IBTUNAM, Av. Universidad, 2001, Col. Chamilpa, CP 62210, Cuernavaca, Mor., México.

Disulfide C-terminal loop fragments derived from AMPs and the presence of peptidases have been previously reported in the skin secretions of different amphibians. However, there are only a few studies on the identification of enzymes in frog skin secretion based on the primary structure of these proteins. Similarly, little data exist regarding the identification of disulfide C-terminal loops at large scale. Therefore, a comprehensive study on this issue certainly could bring in much more information for understanding this molecular process and its biochemical consequences. Thus, the aim of this work was to characterize the presence of disulfide C-terminal loop fragments of AMPs and identify the proteins and probable enzymes present in the completely unknown secretion contents of the frog Lithobates spectabilis. For this purpose, high-resolution mass spectrometry was applied to analyze the skin secretions processed by two different protocols: (1) using a cocktail of enzymatic inhibitors and 2) without any protease inhibitors, maintaining the solution for 2 hours at 10°C. Results from procedure-1, revealed 122 molecular masses, whereas procedure-2 permitted 253 different molecular masses to be identified. Fifty-nine peptides including 22 disulfide C-terminal loop-containing peptides were obtained following procedure-2. Polyacrylamide gel electrophoresis separation, tryptic digestion and LCMS/ MS were used for "de novo" sequencing of 111 different peptides and the unequivocal identification of fifteen proteins including at least three different peptidases. Additionally, it was possible to fully sequence eight peptides, including a ranatuerin-related peptide identified here as Spectabilin, that was subsequently chemically synthesized and showed high antibacterial, antiparasitic and cytotoxic activities.
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http://dx.doi.org/10.2174/0929866523666160505120853DOI Listing
March 2017

Identification of novel cyclic lipopeptides from a positional scanning combinatorial library with enhanced antibacterial and antibiofilm activities.

Eur J Med Chem 2016 Jan 30;108:354-363. Epub 2015 Nov 30.

Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie 34987-2352, FLA, USA. Electronic address:

Treating bacterial infections can be difficult due to innate or acquired resistance mechanisms, and the formation of biofilms. Cyclic lipopeptides derived from fusaricidin/LI-F natural products represent particularly attractive candidates for the development of new antibacterial and antibiofilm agents, with the potential to meet the challenge of bacterial resistance to antibiotics. A positional-scanning combinatorial approach was used to identify the amino acid residues responsible for driving antibacterial activity, and increase the potency of these cyclic lipopeptides. Screening against the antibiotic resistant ESKAPE pathogens revealed the importance of hydrophobic as well as positively charged amino acid residues for activity of this class of peptides. The improvement in potency was especially evident against bacterial biofilms, since the lead cyclic lipopeptide showed promising in vitro and in vivo anti-biofilm activity at the concentration far below its respective MICs. Importantly, structural changes resulting in a more hydrophobic and positively charged analog did not lead to an increase in toxicity toward human cells.
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http://dx.doi.org/10.1016/j.ejmech.2015.11.032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4724249PMC
January 2016

Giant Molluscum Contagiosum in an HIV positive patient.

Int J Infect Dis 2015 Sep 6;38:153-5. Epub 2015 Aug 6.

Tropical and Infectious Diseases Group (GETI), Hospital Militar Central, Universidad Militar Nueva Granada, Bogotá, Colombia; Internal Medicine department, Hospital Militar Central, Bogotá, Colombia.

Molluscum Contagiosum (MC) is a skin infection caused by a double-stranded DNA virus of the family Poxviridae that replicates in the human epidermis, affecting mainly children and young sexually active adults and causing flesh colored papular lesions with central umbilication with an average size of 3-5mm, although atypical lesions that reach great size (Giant Molluscum Contagiosum), 10-15mm, can be seen in almost any immunodeficiency condition. We report the case of a 35 year old male patient with C3 HIV disease with an abdominal pathology associated to skin lesions predominantly in the forehead and scalp that reached sizes over 5mm, diagnosed as Giant Molluscum Contagiosum by skin biopsies.
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http://dx.doi.org/10.1016/j.ijid.2015.07.021DOI Listing
September 2015

Thermodynamic Switch in Binding of Adhesion/Growth Regulatory Human Galectin-3 to Tumor-Associated TF Antigen (CD176) and MUC1 Glycopeptides.

Biochemistry 2015 Jul 20;54(29):4462-74. Epub 2015 Jul 20.

†Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science, Florida Atlantic University, 777 Glades Road, Boca Raton, Florida 33431, United States.

A shift to short-chain glycans is an observed change in mucin-type O-glycosylation in premalignant and malignant epithelia. Given the evidence that human galectin-3 can interact with mucins and also weakly with free tumor-associated Thomsen-Friedenreich (TF) antigen (CD176), the study of its interaction with MUC1 (glyco)peptides is of biomedical relevance. Glycosylated MUC1 fragments that carry the TF antigen attached through either Thr or Ser side chains were synthesized using standard Fmoc-based automated solid-phase peptide chemistry. The dissociation constants (Kd) for interaction of galectin-3 and the glycosylated MUC1 fragments measured by isothermal titration calorimetry decreased up to 10 times in comparison to that of the free TF disaccharide. No binding was observed for the nonglycosylated control version of the MUC1 peptide. The most notable feature of the binding of MUC1 glycopeptides to galectin-3 was a shift from a favorable enthalpy to an entropy-driven binding process. The comparatively diminished enthalpy contribution to the free energy (ΔG) was compensated by a considerable gain in the entropic term. (1)H-(15)N heteronuclear single-quantum coherence spectroscopy nuclear magnetic resonance data reveal contact at the canonical site mainly by the glycan moiety of the MUC1 glycopeptide. Ligand-dependent differences in binding affinities were also confirmed by a novel assay for screening of low-affinity glycan-lectin interactions based on AlphaScreen technology. Another key finding is that the glycosylated MUC1 peptides exhibited activity in a concentration-dependent manner in cell-based assays revealing selectivity among human galectins. Thus, the presentation of this tumor-associated carbohydrate ligand by the natural peptide scaffold enhances its affinity, highlighting the significance of model studies of human lectins with synthetic glycopeptides.
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http://dx.doi.org/10.1021/acs.biochem.5b00555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4520625PMC
July 2015

[Postraumatic mental disorders in traders victims of crime].

Vertex 2014 Nov-Dec;25(118):405-12

Facultad de Ciencias Médicas, Universidad Nacional de La Plata.

Introduction: Crime consequences are not only a security problem; they are also a community health question. Because shop assistants are particularly exposed to crime victimization, they are at risk from suffering posttraumatic stress disorders.

Objectives: To describe posttraumatic symptomatology of crime victimized shop assistants and to explore the relationship between the symptoms and demographic, victim and situational factors.

Materials And Methods: Self-reported information about mental symptomatology was gathered from 126 victimized shop assistants identified during cross-sectional study. Case and control groups were formed to explore association between symptomatology and crime and victim characteristics.

Results: The 20.6% of respondents reported information compatible with posttraumatic stress disorder; the 13 %, with moderate/severe depression and the 69.8% with adjustment disorder. The condition of being a case was associated with the violent characteristic of the crime, with the subtraction of goods and the economic value of the goods.
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June 2015

An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge.

Genome Biol 2014 Mar 25;15(3):R53. Epub 2014 Mar 25.

Background: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance.

Results: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization.

Conclusions: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups.
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http://dx.doi.org/10.1186/gb-2014-15-3-r53DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073084PMC
March 2014

Optimization of physicochemical and pharmacological properties of peptide drugs by glycosylation.

Methods Mol Biol 2013 ;1081:107-36

Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL, USA.

Many biological interactions and functions are mediated by glycans, leading to the emerging importance of carbohydrate and glycoconjugate chemistry in the design of novel drug therapeutics. In addition to direct effects on biological activity, sugar addition appears to alter many physicochemical and pharmacological properties of the peptide backbone. Consequently, glycosylation has been often used to improve various less than optimal features of peptide drug leads.In order to study the effects that naturally occurring and/or nonnatural glycans have on peptide drug solubility, conformation, proteolytic resistance, membrane permeability, and toxicity, it is essential to have convenient synthetic access toward synthesis of glycopeptide analogs. The crucial step in the synthesis of glycopeptides is the introduction of the carbohydrate group. The preformed glycosyl amino acid building block is the most commonly employed approach used in glycopeptide synthesis.In this review, we will describe various synthetic approaches to prepare N- and O-glycopeptides bearing simple monosaccharides as a tool to improve peptide therapeutic efficacy by glycosylation.
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http://dx.doi.org/10.1007/978-1-62703-652-8_8DOI Listing
March 2014

Development of an AlphaScreen assay for discovery of inhibitors of low-affinity glycan-lectin interactions.

Anal Biochem 2013 Aug 16;439(2):123-31. Epub 2013 May 16.

Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL 34987, USA.

The development of high-throughput screening (HTS) assays with increased sensitivity for the identification of potent and selective inhibitors of galectins has been hampered by the weak binding affinities between galectins and their carbohydrate ligands. To circumvent this obstacle, we have developed an AlphaScreen assay for a 384-well plate format in a competitive binding configuration for discovery of new inhibitors of galectin-3. His-tagged galectin-3 was bound to nickel chelate acceptor beads, whereas biotinylated asialofetuin (biotin-ASF), a galectin-3 nanomolar binding partner, was bound to streptavidin-coated donor beads. Inhibitors of the carbohydrate-galectin interaction lead to a reduction of the AlphaScreen signal by competing with the biotin-ASF. The obtained IC50 values for known carbohydrate ligands of galectin-3 are in good agreement with the Kd values reported and measured for galectin-3 by isothermal titration calorimetry (ITC). Thus, the developed AlphaScreen assay in a competitive binding configuration offers several advantages over the existing screening assays for inhibitors of glycan-lectin interactions. In addition, the assay format for the galectin-3/ASF pair could be easily applied in screening for glycan- and/or small molecule-based inhibitors of other members of the galectin family.
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http://dx.doi.org/10.1016/j.ab.2013.04.028DOI Listing
August 2013

Dissecting structural and nucleotide genome-wide variation in inbred Iberian pigs.

BMC Genomics 2013 Mar 5;14:148. Epub 2013 Mar 5.

Center for Research in Agricultural Genomics (CRAG), Campus UAB, Bellaterra, 08193, Spain.

Background: In contrast to international pig breeds, the Iberian breed has not been admixed with Asian germplasm. This makes it an important model to study both domestication and relevance of Asian genes in the pig. Besides, Iberian pigs exhibit high meat quality as well as appetite and propensity to obesity. Here we provide a genome wide analysis of nucleotide and structural diversity in a reduced representation library from a pool (n=9 sows) and shotgun genomic sequence from a single sow of the highly inbred Guadyerbas strain. In the pool, we applied newly developed tools to account for the peculiarities of these data.

Results: A total of 254,106 SNPs in the pool (79.6 Mb covered) and 643,783 in the Guadyerbas sow (1.47 Gb covered) were called. The nucleotide diversity (1.31x10-3 per bp in autosomes) is very similar to that reported in wild boar. A much lower than expected diversity in the X chromosome was confirmed (1.79x10-4 per bp in the individual and 5.83x10-4 per bp in the pool). A strong (0.70) correlation between recombination and variability was observed, but not with gene density or GC content. Multicopy regions affected about 4% of annotated pig genes in their entirety, and 2% of the genes partially. Genes within the lowest variability windows comprised interferon genes and, in chromosome X, genes involved in behavior like HTR2C or MCEP2. A modified Hudson-Kreitman-Aguadé test for pools also indicated an accelerated evolution in genes involved in behavior, as well as in spermatogenesis and in lipid metabolism.

Conclusions: This work illustrates the strength of current sequencing technologies to picture a comprehensive landscape of variability in livestock species, and to pinpoint regions containing genes potentially under selection. Among those genes, we report genes involved in behavior, including feeding behavior, and lipid metabolism. The pig X chromosome is an outlier in terms of nucleotide diversity, which suggests selective constraints. Our data further confirm the importance of structural variation in the species, including Iberian pigs, and allowed us to identify new paralogs for known gene families.
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http://dx.doi.org/10.1186/1471-2164-14-148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3601988PMC
March 2013

Enhanced antimicrobial activity of novel synthetic peptides derived from vejovine and hadrurin.

Biochim Biophys Acta 2013 Jun 9;1830(6):3427-36. Epub 2013 Feb 9.

Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autonóma de México, Avenida Universidad, México.

Background: Microbial antibiotic resistance is a challenging medical problem nowadays. Two scorpion peptides displaying antibiotic activity: hadrurin and vejovine were taken as models for the design of novel shorter peptides with similar activity.

Methods: Using the standard Fmoc-based solid phase synthesis technique of Merrifield twelve peptides (18 to 29 amino acids long) were synthesized, purified and assayed against a variety of multi-drug resistant Gram-negative bacteria from clinical isolates. Hemolytic and antiparasitic activities of the peptides and their possible interactions with eukaryotic cells were verified. Release of the fluorophore calcein from liposomes treated with these peptides was measured.

Results: A peptide with sequence GILKTIKSIASKVANTVQKLKRKAKNAVA), and three analogs: Δ(Α29), Δ(K12-Q18; Ν26-Α29), and K4N Δ(K12-Q18; Ν26-Α29) were shown to inhibit the growth of Gram-negative (E. coli ATCC25922) and Gram-positive bacteria (S. aureus), as well as multi-drug resistant (MDR) clinical isolated. The antibacterial and antiparasitic activities were found with peptides at 0.78 to 25μM and 5 to 25μM concentration, respectively. These peptides have low cytotoxic and hemolytic activities at concentrations significantly exceeding their minimum inhibitory concentrations (MICs), showing values between 40 and 900μM for their EC50, compared to the parent peptides vejovine and hadrurin that at the same concentration of their MICs lysed more than 50% of human erythrocytes cells.

Conclusions: These peptides promise to be good candidates to combat infections caused by Gram-negative bacteria from nosocomial infections.

General Significance: Our results confirm that well designed synthetic peptides can be an alternative for solving the lack of effective antibiotics to control bacterial infections.
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http://dx.doi.org/10.1016/j.bbagen.2013.01.028DOI Listing
June 2013

A bioinformatics approach for integrated transcriptomic and proteomic comparative analyses of model and non-sequenced anopheline vectors of human malaria parasites.

Mol Cell Proteomics 2013 Jan 17;12(1):120-31. Epub 2012 Oct 17.

W Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, Maryland 21205, USA.

Malaria morbidity and mortality caused by both Plasmodium falciparum and Plasmodium vivax extend well beyond the African continent, and although P. vivax causes between 80 and 300 million severe cases each year, vivax transmission remains poorly understood. Plasmodium parasites are transmitted by Anopheles mosquitoes, and the critical site of interaction between parasite and host is at the mosquito's luminal midgut brush border. Although the genome of the "model" African P. falciparum vector, Anopheles gambiae, has been sequenced, evolutionary divergence limits its utility as a reference across anophelines, especially non-sequenced P. vivax vectors such as Anopheles albimanus. Clearly, technologies and platforms that bridge this substantial scientific gap are required in order to provide public health scientists with key transcriptomic and proteomic information that could spur the development of novel interventions to combat this disease. To our knowledge, no approaches have been published that address this issue. To bolster our understanding of P. vivax-An. albimanus midgut interactions, we developed an integrated bioinformatic-hybrid RNA-Seq-LC-MS/MS approach involving An. albimanus transcriptome (15,764 contigs) and luminal midgut subproteome (9,445 proteins) assembly, which, when used with our custom Diptera protein database (685,078 sequences), facilitated a comparative proteomic analysis of the midgut brush borders of two important malaria vectors, An. gambiae and An. albimanus.
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http://dx.doi.org/10.1074/mcp.M112.019596DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3536893PMC
January 2013

Metabolic and miRNA profiling of TMV infected plants reveals biphasic temporal changes.

PLoS One 2011 12;6(12):e28466. Epub 2011 Dec 12.

Instituto de Biotecnología, CICVyA-INTA, Hurlingham, Buenos Aires, Argentina.

Plant viral infections induce changes including gene expression and metabolic components. Identification of metabolites and microRNAs (miRNAs) differing in abundance along infection may provide a broad view of the pathways involved in signaling and defense that orchestrate and execute the response in plant-pathogen interactions. We used a systemic approach by applying both liquid and gas chromatography coupled to mass spectrometry to determine the relative level of metabolites across the viral infection, together with a miRs profiling using a micro-array based procedure. Systemic changes in metabolites were characterized by a biphasic response after infection. The first phase, detected at one dpi, evidenced the action of a systemic signal since no virus was detected systemically. Several of the metabolites increased at this stage were hormone-related. miRs profiling after infection also revealed a biphasic alteration, showing miRs alteration at 5 dpi where no virus was detected systemically and a late phase correlating with virus accumulation. Correlation analyses revealed a massive increase in the density of correlation networks after infection indicating a complex reprogramming of the regulatory pathways, either in response to the plant defense mechanism or to the virus infection itself. Our data propose the involvement of a systemic signaling on early miRs alteration.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028466PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3236191PMC
April 2012

[Mental disorders and working capacity evaluation in psychiatric boards].

Vertex 2011 Jan-Feb;22(95):11-8

Cátedra de Psiquiatría, Universidad Nacional de La Plata.

Introduction: The evaluation by a "Psychiatric Board" of workers in certified sickness absence is a complex practice, and its results have significant effects from a work and health standpoint.

Objectives: To evaluate the inter-rater reliability in the psychiatric board and the association between self-reported measurement and the board judgment.

Materials And Method: information was obtained from 68 school teachers on sick leaves through self-reported scales (Zung and Conde Self-rating Scale for Depression; Maslach Burnout Inventory; Effort-reward Imbalance Questionnaire; and Self Reported Present Health State Scale). Blind clinical psychiatric evaluation regarding the former information was carried out. Two independent scores of the Global Assessment Scale; Clinical Global Impression; Brief Psychiatric Rating Scale and Reliability Scale were obtained.

Results: The results support the reliability of the instruments and that they can provide important information to the Psychiatric Board.
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July 2011

Transcriptomes of the desiccation-tolerant resurrection plant Craterostigma plantagineum.

Plant J 2010 Jul 29;63(2):212-28. Epub 2010 Apr 29.

Department of Biology, University of Copenhagen, Copenhagen, Denmark.

Studies of the resurrection plant Craterostigma plantagineum have revealed some of the mechanisms which these desiccation-tolerant plants use to survive environments with extreme dehydration and restricted seasonal water. Most resurrection plants are polyploid with large genomes, which has hindered efforts to obtain whole genome sequences and perform mutational analysis. However, the application of deep sequencing technologies to transcriptomics now permits large-scale analyses of gene expression patterns despite the lack of a reference genome. Here we use pyro-sequencing to characterize the transcriptomes of C. plantagineum leaves at four stages of dehydration and rehydration. This reveals that genes involved in several pathways, such as those required for vitamin K and thiamin biosynthesis, are tightly regulated at the level of gene expression. Our analysis also provides a comprehensive picture of the array of cellular responses controlled by gene expression that allow resurrection plants to survive desiccation.
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http://dx.doi.org/10.1111/j.1365-313X.2010.04243.xDOI Listing
July 2010

Transcriptome analysis of the Brucella abortus BvrR/BvrS two-component regulatory system.

PLoS One 2010 Apr 21;5(4):e10216. Epub 2010 Apr 21.

Departamento de Microbiología y Parasitología, Universidad de Navarra, Pamplona, Spain.

Background: The two-component BvrR/BvrS system is essential for Brucella abortus virulence. It was shown previously that its dysfunction alters the expression of some major outer membrane proteins and the pattern of lipid A acylation. To determine the genes regulated by BvrR/BvrS, we performed a whole-genome microarray analysis using B. abortus RNA obtained from wild type and bvrR mutant cells grown in the same conditions.

Methodology/principal Findings: A total of 127 differentially expressed genes were found: 83 were over expressed and 44 were less expressed in the bvrR mutant. Two operons, the phosphotransferase system and the maltose transport system, were down-regulated. Several genes involved in cell envelope or outer membrane biogenesis were differentially expressed: genes for outer membrane proteins (omp25a, omp25d), lipoproteins, LPS and fatty acid biosynthesis, stress response proteins, chaperones, flagellar genes, and twelve genes encoding ABC transport systems. Ten genes related with carbon metabolism (pckA and fumB among others) were up-regulated in the bvrR mutant, and denitrification genes (nirK, norC and nosZ) were also regulated. Notably, seven transcriptional regulators were affected, including VjbR, ExoR and OmpR that were less expressed in the bvrR mutant. Finally, the expression of eleven genes which have been previously related with Brucella virulence was also altered.

Conclusions/significance: All these data corroborate the impact of BvrR/BvrS on cell envelope modulation, confirm that this system controls the carbon and nitrogen metabolism, and suggest a cross-talk among some regulators to adjust the Brucella physiology to the shift expected to occur during the transit from the extracellular to the intracellular niche.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0010216PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2858072PMC
April 2010

Virus infection elevates transcriptional activity of miR164a promoter in plants.

BMC Plant Biol 2009 Dec 30;9:152. Epub 2009 Dec 30.

Instituto de Biotecnología, CICVyA, INTA Castelar, CP 1686 Hurlingham, Buenos Aires, Argentina.

Background: Micro RNAs (miRs) constitute a large group of endogenous small RNAs that have crucial roles in many important plant functions. Virus infection and transgenic expression of viral proteins alter accumulation and activity of miRs and so far, most of the published evidence involves post-transcriptional regulations.

Results: Using transgenic plants expressing a reporter gene under the promoter region of a characterized miR (P-miR164a), we monitored the reporter gene expression in different tissues and during Arabidopsis development. Strong expression was detected in both vascular tissues and hydathodes. P-miR164a activity was developmentally regulated in plants with a maximum expression at stages 1.12 to 5.1 (according to Boyes, 2001) along the transition from vegetative to reproductive growth. Upon quantification of P-miR164a-derived GUS activity after Tobacco mosaic virus Cg or Oilseed rape mosaic virus (ORMV) infection and after hormone treatments, we demonstrated that ORMV and gibberellic acid elevated P-miR164a activity. Accordingly, total mature miR164, precursor of miR164a and CUC1 mRNA (a miR164 target) levels increased after virus infection and interestingly the most severe virus (ORMV) produced the strongest promoter induction.

Conclusion: This work shows for the first time that the alteration of miR pathways produced by viral infections possesses a transcriptional component. In addition, the degree of miR alteration correlates with virus severity since a more severe virus produces a stronger P-miR164a induction.
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http://dx.doi.org/10.1186/1471-2229-9-152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2809068PMC
December 2009

Small-molecule activators of insulin-degrading enzyme discovered through high-throughput compound screening.

PLoS One 2009 22;4(4):e5274. Epub 2009 Apr 22.

Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America.

Background: Hypocatabolism of the amyloid beta-protein (Abeta) by insulin-degrading enzyme (IDE) is implicated in the pathogenesis of Alzheimer disease (AD), making pharmacological activation of IDE an attractive therapeutic strategy. However, it has not been established whether the proteolytic activity of IDE can be enhanced by drug-like compounds.

Methodology/principal Findings: Based on the finding that ATP and other nucleotide polyphosphates modulate IDE activity at physiological concentrations, we conducted parallel high-throughput screening campaigns in the absence or presence of ATP and identified two compounds--designated Ia1 and Ia2--that significantly stimulate IDE proteolytic activity. Both compounds were found to interfere with the crosslinking of a photoaffinity ATP analogue to IDE, suggesting that they interact with a bona fide ATP-binding domain within IDE. Unexpectedly, we observed highly synergistic activation effects when the activity of Ia1 or Ia2 was tested in the presence of ATP, a finding that has implications for the mechanisms underlying ATP-mediated activation of IDE. Notably, Ia1 and Ia2 activated the degradation of Abeta by approximately 700% and approximately 400%, respectively, albeit only when Abeta was presented in a mixture also containing shorter substrates.

Conclusions/significance: This study describes the first examples of synthetic small-molecule activators of IDE, showing that pharmacological activation of this important protease with drug-like compounds is achievable. These novel activators help to establish the putative ATP-binding domain as a key modulator of IDE proteolytic activity and offer new insights into the modulatory action of ATP. Several larger lessons abstracted from this screen will help inform the design of future screening campaigns and facilitate the eventual development of IDE activators with therapeutic utility.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0005274PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2668070PMC
June 2009

BRCT domains: phosphopeptide binding and signaling modules.

Front Biosci 2008 May 1;13:5905-15. Epub 2008 May 1.

1Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.

The BRCA1 C-terminus (BRCT) domains are essential for the tumor suppressor function of BRCA1, and have been found in a variety of proteins from bacteria to men. Recent studies demonstrate that the BRCT domain constitutes a novel phosphopeptide binding region. In this review we seek to discuss the recent biochemical and structural data that have helped elucidate the molecular basis of BRCT domain function and BRCT-mediated interactions, with special emphasis on the role of phospho-specific interactions in key networks that regulate DNA repair. Finally we offer predictions on additional phospho-interacting BRCT domains and potential in vivo binding sites for several BRCT domains.
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http://dx.doi.org/10.2741/3125DOI Listing
May 2008

Structure of the SOCS4-ElonginB/C complex reveals a distinct SOCS box interface and the molecular basis for SOCS-dependent EGFR degradation.

Structure 2007 Nov;15(11):1493-504

University of Oxford, Structural Genomics Consortium, Botnar Research Centre, Oxford OX3 7LD, United Kingdom.

Tyrosine kinase signaling is tightly controlled by negative feedback inhibitors including suppressors of cytokine signaling (SOCS). SOCS assemble as SH2 domain substrate recognition modules in ElonginB/C-cullin ubiquitin ligases. In accordance, SOCS4 reduces STAT3 signaling from EGFR through increased receptor degradation. Variable C-termini in SOCS4-SOCS7 exclude these family members from a SOCS2-type domain arrangement in which a strictly conserved C terminus determines domain packing. The structure of the SOCS4-ElonginC-ElonginB complex reveals a distinct SOCS structural class. The N-terminal ESS helix functionally replaces the CIS/SOCS1-SOCS3 family C terminus in a distinct SH2-SOCS box interface that facilitates further interdomain packing between the extended N- and C-terminal regions characteristic for this subfamily. Using peptide arrays and calorimetry the STAT3 site in EGFR (pY(1092)) was identified as a high affinity SOCS4 substrate (K(D) = 0.5 microM) revealing a mechanism for EGFR degradation. SOCS4 also bound JAK2 and KIT with low micromolar affinity, whereas SOCS2 was specific for GH-receptor.
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http://dx.doi.org/10.1016/j.str.2007.09.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225448PMC
November 2007

Phase I clinical evaluation of a synthetic oligosaccharide-protein conjugate vaccine against Haemophilus influenzae type b in human adult volunteers.

Clin Vaccine Immunol 2006 Sep;13(9):1052-6

Institute for Tropical Medicine Pedro Kouri, Autopista Novia del Mediodía, Km 6, La Lisa, Apdo 601, Marianao 13, Havana 11300, Cuba.

Since 1989, we have been involved in the development of a vaccine against Haemophilus influenzae type b. The new vaccine is based on the conjugation of synthetic oligosaccharides to tetanus toxoid. Our main goals have been (i) to verify the feasibility of using the synthetic antigen and (ii) to search for new production alternatives for this important infant vaccine. Overall, eight trials have already been conducted with adults, children (4 to 5 years old), and infants. We have described herein the details from the first two phase I clinical trials conducted with human adult volunteers under double blind, randomized conditions. The participants each received a single intramuscular injection to evaluate safety and initial immunogenicity. We have found an excellent safety profile and an antibody response similar to the one observed for the control vaccine.
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http://dx.doi.org/10.1128/CVI.00144-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1563574PMC
September 2006

Galactans from cystocarpic plants of the red seaweed Callophyllis variegata (Kallymeniaceae, Gigartinales).

Carbohydr Res 2005 Dec 9;340(18):2742-51. Epub 2005 Nov 9.

Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina.

The polysaccharide extracted from cystocarpic Callophyllis variegata was fractionated with potassium chloride yielding three small fractions that precipitated in the ranges of 0-0.05 M KCl, 1.20-1.25 M KCl, and 1.80-2.00 M KCl, and a main product soluble in 2.00 M KCl. These fractions were analyzed, and as the first one contained very high amounts of protein, it was not studied further. Structural analysis of the rest of the fractions (F1-F3) was carried out by methylation, desulfation-methylation, IR, and 13C NMR spectroscopy. The results are consistent for F1 with a carrageenan-type backbone mainly constituted by beta-D-galactose 2-sulfate linked to alpha-D-galactose 2,3,6-trisulfate and beta-D-galactose 2,4-disulfate linked to 3,6-anhydro-D-galactose 2-sulfate as dominant diads. In F2 these diads are present together with low amounts of beta-D-galactose 2-sulfate linked to 3,6-anhydro-D-galactose 2-sulfate, whose contribution becomes higher in F3. In addition, minor but significant amounts of L-galactose were detected. F1-F3 showed potent antiviral activity against herpes simplex types 1 and 2 and dengue type 2.
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http://dx.doi.org/10.1016/j.carres.2005.10.001DOI Listing
December 2005