110 results match your criteria alpha-like toxin


Microarray Analysis of Group B Streptococci Causing Invasive Neonatal Early- and Late-onset Infection.

Pediatr Infect Dis J 2020 05;39(5):449-453

From the Department of Pediatrics, University Hospital Carl Gustav Carus, Dresden, Germany.

Background: Group B Streptococcus is the leading cause of meningitis and sepsis in newborns. Until now, there is no data of fast and simple typing of group B Streptococcus virulence factors using a genetic microarray and comparing these data to clinical manifestations.

Methods: A prospective active surveillance study was conducted via 2 independent and nationwide reporting systems, the German Pediatric Surveillance Unit (ESPED) and the Laboratory Sentinel Group at Robert Koch-Institute. Read More

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Determination of surface proteins profile, capsular genotyping, and antibiotic susceptibility patterns of Group B Streptococcus isolated from urinary tract infection of Iranian patients.

BMC Res Notes 2019 Jul 19;12(1):437. Epub 2019 Jul 19.

Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.

Objectives: Group B Streptococcus (GBS) is an important opportunistic bacteria that causes a wide range of infections including neonatal sepsis, meningitis, pneumonia, soft tissue and urinary tract infections (UTI). The aim of this study was to evaluate the antimicrobial susceptibility patterns, surface proteins and capsular types of GBS isolates.

Results: 100 of UTI isolates were confirmed as GBS. Read More

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Isolation and Characterization of Insecticidal Toxins from the Venom of the North African Scorpion, .

Toxins (Basel) 2019 04 25;11(4). Epub 2019 Apr 25.

Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.

Various bioactive peptides have been identified in scorpion venom, but there are many scorpion species whose venom has not been investigated. In this study, we characterized venom components of the North African scorpion, , by mass spectrometric analysis and evaluated their insect toxicity. This is the first report of chemical and biological characterization of the venom. Read More

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Refined structure of BeM9 reveals arginine hand, an overlooked structural motif in scorpion toxins affecting sodium channels.

Proteins 2018 10 8;86(10):1117-1122. Epub 2018 Sep 8.

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.

Sodium channel alpha-toxins from scorpion venom (α-NaTx) inhibit the inactivation of voltage-gated sodium channels. We used solution NMR to investigate the structure of BeM9 toxin from Mesobuthus eupeus scorpion, a prototype α-NaTx classified as an "α-like" toxin due to its wide spectrum of activity on insect and mammalian channels. We identified a new motif that we named "arginine hand," whereby arginine side chain forms several hydrogen bonds with main chain atoms. Read More

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October 2018

Molecular characteristics of Streptococcus agalactiae in a mother-baby prospective cohort study: Implication for vaccine development and insights into vertical transmission.

Vaccine 2018 04 5;36(15):1941-1948. Epub 2018 Mar 5.

Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China. Electronic address:

Background: Streptococcus agalactiae (GBS) is a leading cause of neonatal sepsis and meningitis in many countries. This study aimed to determine the molecular characteristics of GBS colonized in mothers and their infants so as to provide implication for vaccine strategies and confirm vertical transmission.

Methods: A prospective cohort study was conducted to recruit 1815 mother-neonate pairs. Read More

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Non-homeostatic body weight regulation through a brainstem-restricted receptor for GDF15.

Nature 2017 10 27;550(7675):255-259. Epub 2017 Sep 27.

NGM Biopharmaceuticals, South San Francisco, California 94080, USA.

Under homeostatic conditions, animals use well-defined hypothalamic neural circuits to help maintain stable body weight, by integrating metabolic and hormonal signals from the periphery to balance food consumption and energy expenditure. In stressed or disease conditions, however, animals use alternative neuronal pathways to adapt to the metabolic challenges of altered energy demand. Recent studies have identified brain areas outside the hypothalamus that are activated under these 'non-homeostatic' conditions, but the molecular nature of the peripheral signals and brain-localized receptors that activate these circuits remains elusive. Read More

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October 2017

Design of sodium channel ligands with defined selectivity - a case study in scorpion alpha-toxins.

FEBS Lett 2017 10 21;591(20):3414-3420. Epub 2017 Sep 21.

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.

Scorpion α-toxins are polypeptides that inhibit voltage-gated sodium channel inactivation. They are divided into mammal, insect and α-like toxins based on their relative activity toward different phyla. Several factors are currently known to influence the selectivity, which are not just particular amino acid residues but also general physical, chemical, and topological properties of toxin structural modules. Read More

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October 2017

Comparative analyses and implications for antivenom serotherapy of four Moroccan scorpion Buthus occitanus venoms: Subspecies tunetanus, paris, malhommei, and mardochei.

Toxicon 2018 Jul 13;149:26-36. Epub 2017 Jul 13.

Aix Marseille Université, CNRS, CRN2M UMR7286, 13344, Marseille, France. Electronic address:

Temporary passive immunity such as serotherapy against venoms requires the full knowledge of all venom's components. Here, four venoms from Moroccan common yellow scorpions belonging to Buthus occitanus, subspecies tunetanus, paris, malhommei, and mardochei, all collected in four different restricted areas, were analysed in deep. They were fractionated by reversed-phase high-performance liquid chromatography (RP-HPLC) and their molecular masse profile determined by off-line MALDI-TOF mass spectrometry. Read More

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The scorpion toxin Bot IX is a potent member of the α-like family and has a unique N-terminal sequence extension.

FEBS Lett 2016 09 1;590(18):3221-32. Epub 2016 Sep 1.

Aix Marseille Université, CNRS, CRN2M, UMR7286, PFRN-CAPM, Marseille, France.

We report the detailed chemical, immunological and pharmacological characterization of the α-toxin Bot IX from the Moroccan scorpion Buthus occitanus tunetanus venom. Bot IX, which consists of 70 amino acids, is a highly atypical toxin. It carries a unique N-terminal sequence extension and is highly lethal in mice. Read More

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September 2016

Target-Driven Positive Selection at Hot Spots of Scorpion Toxins Uncovers Their Potential in Design of Insecticides.

Mol Biol Evol 2016 08 4;33(8):1907-20. Epub 2016 Apr 4.

Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China

Positive selection sites (PSSs), a class of amino acid sites with an excess of nonsynonymous to synonymous substitutions, are indicators of adaptive molecular evolution and have been detected in many protein families involved in a diversity of biological processes by statistical approaches. However, few studies are conducted to evaluate their functional significance and the driving force behind the evolution (i.e. Read More

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ON and OFF retinal ganglion cells differentially regulate serotonergic and GABAergic activity in the dorsal raphe nucleus.

Sci Rep 2016 05 16;6:26060. Epub 2016 May 16.

Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, PR China.

The dorsal raphe nucleus (DRN), the major source of serotonergic input to the forebrain, receives excitatory input from the retina that can modulate serotonin levels and depressive-like behavior. In the Mongolian gerbil, retinal ganglion cells (RGCs) with alpha-like morphological and Y-like physiological properties innervate the DRN with ON DRN-projecting RGCs out numbering OFF DRN-projecting RGCs. The DRN neurons targeted by ON and OFF RGCs are unknown. Read More

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Parkinson's disease-like forelimb akinesia induced by BmK I, a sodium channel modulator.

Behav Brain Res 2016 07 20;308:166-76. Epub 2016 Apr 20.

Laboratory of Neuropharmacology and Neurotoxicology, School of Life Science, Shanghai University, Shanghai, China.

Parkinson's disease (PD) is a neurodegenerative disorder and characterized by motor disabilities which are mostly linked with high levels of synchronous oscillations in the basal ganglia neurons. Voltage-gated sodium channels (VGSCs) play a vital role in the abnormal electrical activity of neurons in the globus pallidus (GP) and the subthalamic nucleus (STN) in PD. BmK I, a α-like toxin purified from the Chinese scorpion Buthus martensi Karsch, has been identified a site-3-specific modulator of VGSCs. Read More

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Morpho-histology of head kidney of female catfish Heteropneustes fossilis: seasonal variations in melano-macrophage centers, melanin contents and effects of lipopolysaccharide and dexamethasone on melanins.

Fish Physiol Biochem 2016 Oct 16;42(5):1287-306. Epub 2016 Mar 16.

School of Biotechnology, Banaras Hindu University, Varanasi, 221005, India.

In the catfish Heteropneustes fossilis, the anterior kidney is a hemopoietic tissue which surrounds the adrenal homologues, interrenal (IR) and chromaffin tissues corresponding to the adrenal cortical and adrenal medulla of higher mammals. The IR tissue is arranged in cell cords around the posterior cardinal vein (PCV) and its tributaries and secretes corticosteroids. The chromaffin tissue is scattered singly or in nests of one or more cells around the epithelial lining of the PCV or blood capillaries within the IR tissue. Read More

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October 2016

The Dorsal Raphe Nucleus Receives Afferents From Alpha-Like Retinal Ganglion Cells and Intrinsically Photosensitive Retinal Ganglion Cells in the Rat.

Invest Ophthalmol Vis Sci 2015 Dec;56(13):8373-81

School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of China 2Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of.

Purpose: A retinal projection into the dorsal raphe nucleus (DRN), namely, the retino-raphe projection, exists in many species. The rat is one of several species in which a retino-raphe projection has been described; however, the retinal ganglion cell (RGC) types that contribute to this pathway are unknown.

Methods: Retrograde tracing via cholera toxin subunit B (CTB) was used to reveal DRN-projecting RGCs in rats, combined with intracellular injection in vitro, melanopsin immunostaining in whole-mounted retinas, and serotonin immunostaining to define the DRN. Read More

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December 2015

β/δ-PrIT1, a highly insecticidal toxin from the venom of the Brazilian spider Phoneutria reidyi (F.O. Pickard-Cambridge, 1897).

Toxicon 2015 Sep 26;104:73-82. Epub 2015 Jul 26.

Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil. Electronic address:

A potent insecticidal toxin, β/δ-PrIT1, molecular mass of 5598.86 [M+H](+), was characterized from Phoneutria reidyi spider venom. Its partial amino acid sequence showed high similarity with insecticidal spider toxins from the genus Phoneutria. Read More

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September 2015

Electrophysiological characterization of the first Tityus serrulatus alpha-like toxin, Ts5: Evidence of a pro-inflammatory toxin on macrophages.

Biochimie 2015 Aug 20;115:8-16. Epub 2015 Apr 20.

Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. Electronic address:

Tityus serrulatus (Ts) venom is composed of mainly neurotoxins specific for voltage-gated K(+) and Na(+) channels, which are expressed in many cells such as macrophages. Macrophages are the first line of defense invasion and they participate in the inflammatory response of Ts envenoming. However, little is known about the effect of Ts toxins on macrophage activation. Read More

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Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources.

J Med Microbiol 2014 Jan 22;63(Pt 1):90-98. Epub 2013 Oct 22.

Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy.

A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). Read More

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January 2014

Somatostatin preserved blood brain barrier against cytokine induced alterations: possible role in multiple sclerosis.

Biochem Pharmacol 2013 Aug 13;86(4):497-507. Epub 2013 Jun 13.

Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.

Multiple sclerosis (MS) is an inflammatory neurological disorder associated with demyelination, impaired blood brain barrier (BBB), axonal damage and neuronal loss. In the present study, we measured somatostatin (SST) and tumor necrosis factor-α (TNF-α) like immunoreactivity in CSF samples from MS and non-MS patients. We also examined the role of SST in cytokines and lipopolysaccharide (LPS)-induced damage to the BBB using human brain endothelial cells in culture. Read More

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Two recombinant α-like scorpion toxins from Mesobuthus eupeus with differential affinity toward insect and mammalian Na(+) channels.

Biochimie 2013 Sep 4;95(9):1732-40. Epub 2013 Jun 4.

Group of Animal Innate Immunity, State Key Laboratory of Integrated Management of Pest, Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.

α-Scorpion toxins are modulators of voltage-gated Na(+) channels (Navs), which bind to the receptor site 3 to inhibit the fast inactivation of the channels. MeuNaTxα-12 and MeuNaTxα-13 are two new α-scorpion toxin-like peptides identified by cDNA cloning from the scorpion Mesobuthus eupeus with unknown functions. Here, we report their recombinant production, oxidative refolding, structural and functional features. Read More

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September 2013

Chromatic coding from cone-type unselective circuits in the mouse retina.

Neuron 2013 Feb;77(3):559-71

Centre for Integrative Neuroscience (CIN) /Centre for Ophthalmology, University of Tübingen, Otfried-Müller-Strasse 25, 72076 Tübingen, Germany.

Retinal specializations such as cone-photoreceptor opsin-expression gradients, as found in several vertebrate species, are intuitively considered detrimental to color vision. In mice, the majority of cones coexpress both "blue" and "green" opsin. The coexpression ratio changes along the dorsoventral axis, resulting in a "green"-dominant dorsal and a "blue"-dominant ventral retina. Read More

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February 2013

Homology modeling and molecular dynamics simulation of odonthubuthus doriae (Od1) scorpion toxin in comparison to the BmK M1.

Bioinformation 2012 31;8(10):474-8. Epub 2012 May 31.

All of the α-subgroups share similarity in their sequence and structure but different in the toxicity to various voltage-gated sodium channels (VGSCs). We modeled the first 3D structural model of the Od1 based on BmK M1 using homology modeling. The reliability of model for more investigation and compare to BmK M1 has been examined and confirmed. Read More

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Recombinant expression, purification, and characterization of scorpion toxin BmαTX14.

Protein Expr Purif 2012 Apr 10;82(2):325-31. Epub 2012 Feb 10.

State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China.

Long-chain and cysteine-rich scorpion toxins exhibit various pharmacological profiles for different voltage-gated sodium channel subtypes. However, the exploration of toxin structure-function relationships has progressed slowly due to the difficulty of obtaining synthetic or recombinant peptides. We now report that we have established an effective expression and purification approach for the novel scorpion toxin BmαTX14. Read More

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Phenotypes, genotypes, serotypes and molecular epidemiology of erythromycin-resistant Streptococcus agalactiae in Italy.

Eur J Clin Microbiol Infect Dis 2012 Aug 26;31(8):1741-7. Epub 2011 Nov 26.

Institute of Microbiology, Department of Experimental and Applied Medicine, University of Brescia, P. le Spedali Civili, 1, 25123, Brescia, Italy.

The purpose of this investigation was to analyse Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected in Italy from vaginal and urine samples in respect to their clonality, distribution of virulence factors and antimicrobial resistance determinants. Three hundred and eighty-eight GBS were recovered from clinical samples. They were analysed for antibiotic resistance profiling. Read More

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Population structure, virulence factors and resistance determinants of invasive, non-invasive and colonizing Streptococcus agalactiae in Poland.

J Antimicrob Chemother 2010 Sep 27;65(9):1907-14. Epub 2010 Jun 27.

National Medicines Institute, ul Chełmska 30/34, 00-725 Warsaw, Poland.

Objectives: To analyse Streptococcus agalactiae (group B Streptococcus; GBS) isolates collected in Poland from various human infections and carriage in respect of their clonality, distribution of virulence factors and antimicrobial resistance determinants, including the detection of transposons involved in the dissemination of antimicrobial resistance.

Methods: One hundred and fourteen GBS isolates were analysed by multilocus sequence typing (MLST), serotyping and detection of alp genes of the alpha-like-protein (Alp) family. Determinants of resistance to macrolides and tetracycline, and associated transposons, were detected by PCR and analysed by sequencing. Read More

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September 2010

Surface protein EF3314 contributes to virulence properties of Enterococcus faecalis.

Int J Artif Organs 2009 Sep;32(9):611-20

Respiratory and Systemic Disease Unit, Department of Infectious, Parasitic, and Immune-mediated Diseases, National Health Institute (ISS), Rome, Italy.

Purpose: Identification of putative new virulence factors as additional targets for therapeutic approaches alternative to antibiotic treatment of multi-resistant enterococcal infections.

Methods: The EF3314 gene, coding for a putative surface-exposed antigen, was identified by the analysis of the Enterococcus faecalis V583 genome for LPXTG-motif cell wall anchor surface protein genes. A non-polar EF3314 gene deletion mutant in the E. Read More

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September 2009

Full characterization of three toxins from the Androctonus amoreuxi scorpion venom.

Toxicon 2009 Sep 30;54(4):460-70. Epub 2009 May 30.

CNRS UMR 6231, CRN2M and CAPM, Université de la Méditerranée et Université Paul Cézanne. Faculté de Médecine - Secteur Nord, CS80011, Bd Pierre Dramard, 13344 Marseille Cedex 15, France.

In this study, we have characterized the immunological and pharmacological properties of the three major alpha-type toxins from the scorpion Androctonus amoreuxi, AamH1, AamH2 and AamH3, which were previously described as putative toxins from cDNAs [Chen, T. et al., 2003. Read More

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September 2009

The alpha-like scorpion toxin BmK I enhances membrane excitability via persistent sodium current by preventing slow inactivation and deactivation of rNav1.2a expressed in Xenopus Oocytes.

Toxicol In Vitro 2009 Jun 30;23(4):561-8. Epub 2008 Dec 30.

Graduate School of Chinese Academy of Sciences, Shanghai Institute of Physiology, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, PR China.

BmK I is classified as alpha-like scorpion toxin that specifically binds the voltage-gated sodium channels via receptor site-3. Previous results showed BmK I induced epileptiform responses in rats via intra-hippocampal injection, but the mechanism has yet to be clarified. In this study, using two-electrode voltage/current clamp technique, we determined the effects of BmK I on rNav1. Read More

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Dinucleotides docking to scorpion polypeptide toxins: a molecular modeling method for protein functional site recognition.

Biochem Biophys Res Commun 2009 Jan 5;378(2):157-61. Epub 2008 Nov 5.

School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 17, 103 Wenhua Road, Shenhe District, Shenyang, Liaoning Province 110016, PR China.

To understand the principles underlying protein folding, many molecular modeling methods are being developed for predicting functional positions. In this work, fully flexible dinucleotides d(pApA), d(pApC), d(pApG), d(pApT), d(pCpA), d(pCpC), d(pCpG), d(pCpT), d(pGpA), d(pGpC), d(pGpG), d(pGpT), d(pTpA), d(pTpC), d(pTpG), and d(pTpT) were first docked onto the surface of scorpion polypeptide toxins (LqhIT2, PDB ID:2I61) and homology modeled ANEPIII. Automated docking was able to identify sites on scorpion polypeptide toxins where favorable nucleotide interactions can occur, and those sites were in agreement with the mutation data of this protein published recently [I. Read More

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January 2009

The study of sodium channels involved in pain responses using specific modulators.

Sheng Li Xue Bao 2008 Oct;60(5):628-34

School of Life Sciences, Shanghai University, Shanghai 200444, China.

Voltage-gated sodium channels (VGSCs) are transmembrane proteins responsible for generation and conduction of action potentials in excitable cells. Physiological and pharmacological studies have demonstrated that VGSCs play a critical role in chronic pain associated with tissue or nerve injury. Many long-chain peptide toxins (60-76 amino acid residues) purified from the venom of Asian scorpion Buthus martensii Karsch (BmK) are investigated to be sodium channel-specific modulators. Read More

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October 2008