Publications by authors named "Ahmed K El-Sayed"

5 Publications

  • Page 1 of 1

Ergosterol Peroxide from the Egyptian Red Lingzhi or Reishi Mushroom, Ganoderma resinaceum (Agaricomycetes), Showed Preferred Inhibition of MCF-7 over MDA-MB-231 Breast Cancer Cell Lines.

Int J Med Mushrooms 2020 ;22(4):389-396

Chemistry Department, Faculty of Science, Damietta University, New Damietta City, Egypt; Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.

Ergosterol peroxide and ganoderic acid AMI were isolated for the first time from the mycelium of the Egyptian Ganoderma resinaceum mushroom. The structure of these two metabolites was established by detailed analysis of 1D and 2D NMR. The isolated compounds were tested for their antitumor in vitro activities in MCF-7 and MDA-MB-231 breast cancer cell lines. Ergosterol peroxide showed preferred inhibition of MCF-7 (ER +ve) cell lines relative to MDA-MB-231 (ER -ve) cell lines with an IC50 of 1.18 μM and 12.82 μM respectively. Our data suggest that ergosterol peroxide targets estrogen receptors.
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http://dx.doi.org/10.1615/IntJMedMushrooms.2020034223DOI Listing
February 2021

Identification and Functional Analysis of Temperate Siphoviridae Bacteriophages of .

Viruses 2020 05 31;12(6). Epub 2020 May 31.

Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland.

is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable infections. In search for new specific bacteriophages, 20 clinical strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family . The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52-54 predicted genes, an site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two strains. In conclusion, we have isolated and characterized three novel temperate phages that infect .
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http://dx.doi.org/10.3390/v12060604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354433PMC
May 2020

Gross morphological features of the air sacs of the hooded crow (Corvus cornix).

Anat Histol Embryol 2020 Mar 15;49(2):159-166. Epub 2019 Oct 15.

Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt.

Air sacs are considered to be one of the controlling factors of bird behaviour and habits in addition to their roles in ventilation, regulating body temperature, swimming and flight. As a scavenger and an omnivorous flight bird, air sacs of the hooded crow were the focus of this study. Eight healthy, adult hooded crows were used to examine the morphological characteristics of the air sacs, which were examined grossly and with latex and cast preparations. In general, the morphological overview of the hooded crow air sacs is similar to other avian species. We observed nine air sacs; four paired sacs (cervical, cranial thoracic, caudal thoracic and abdominal air sacs) and one unpaired sac; the clavicular air sac. The cervical air sac communicated to the lung through the medioventral bronchus and had three diverticula; intermuscular, subscapular and subcutaneous. The clavicular air sac communicated with lung through the medioventral bronchus and had subscapular, axillary, humeral, subpectoral and sternal diverticula. The cranial and caudal thoracic air sacs were communicated with lung through the lateroventral bronchi and the both sacs did not have any diverticula. The abdominal air sacs were posterior to the caudal thoracic air sacs. The left abdominal sac was the largest air sac. The right and left abdominal sacs gave off branches to diverticula that pneumatized synsacrum. The abdominal air sacs gave off femoral diverticula behind the hip joint as well as perirenal diverticula.
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http://dx.doi.org/10.1111/ahe.12504DOI Listing
March 2020

Heterologous expression, purification, immobilization and characterization of recombinant α-amylase AmyLa from Laceyella sp. DS3.

Int J Biol Macromol 2019 Jul 3;132:1274-1281. Epub 2019 Apr 3.

Botany and Microbiology Department, Faculty of Science, Damietta University, Egypt. Electronic address:

AmyLa α-amylase gene from Laceyella sp. DS3 was heterologously expressed in E. coli BL21. E. coli BL21 maximally expressed AmyLa after 4 h of adding 0.02 mM IPTG at 37 °C. The recombinant AmyLa α-amylase was purified 2.19-fold through gel filtration and ion exchange chromatography. We immobilized the purified recombinant AmyLa α-amylase on four carriers; chitosan had the best efficiency. The recombinant free and the immobilized AmyLa α-amylase showed optimum activity in the pH ranges of 6.0-7.0 and 4.0-7.0, respectively and possessed an optimum temperature of 55 °C. The free enzyme had activation energy, Km, and Vmax of 291.5 kJ, 1.5 mg/ml, and 6.06 mg/min, respectively. The immobilized enzyme had activation energy, Km, and Vmax of 309.74 kJ, 6.67 mg/ml, and 50 mg/min, respectively. The immobilized enzyme was calcium-independent and insensitive (relative to the free enzyme) to metals. It could also be reused for seven cycles.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.04.010DOI Listing
July 2019

Purification, sequencing, and biochemical characterization of a novel calcium-independent α-amylase AmyTVE from Thermoactinomyces vulgaris.

Appl Biochem Biotechnol 2013 Jun 4;170(3):483-97. Epub 2013 Apr 4.

Botany Department, Faculty of Science, Damietta University, P.O. Box 34517, New Damietta, Egypt.

α-Amylase from Thermoactinomyces vulgaris was highly purified 48.9-fold by ammonium sulfate precipitation, gel filtration on Sephadex G-50 column, and ion exchange chromatography column of DEAE-cellulose. The molecular weight of the enzyme was estimated to be 135 and 145 kDa by SDS-PAGE. Its high molecular weight is due to high glycosylation. The purified amylase exhibited maximal activity at pH 6.0 to 7.0 and was stable in the range of pH 4.0 to 9.0. The optimum temperature for its activity was 50 °C. The enzyme half-life time was 120 min at 50 °C, suggesting intermediate temperature stable α-amylase. The enzyme was sensitive to different metal ions, including NaCl, CoCl(2), and CaCl(2), and to different concentrations of EDTA. The enzyme activity was inhibited in the presence of 1 mM CaCl(2), suggesting that it is a calcium-independent α-amylase. The TLC showed that the amylase hydrolyzed starch to produce large maltooligosaccharides as the main products. A 1.1-kb DNA fragment of the putative α-amylase gene (amy TVE) from T. vulgaris was amplified by using two specific newly designed primers. Sequencing analysis showed 56.2 % similarity to other Thermoactinomyces α-amylases with two conserved active sites confirming its function.
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http://dx.doi.org/10.1007/s12010-013-0201-7DOI Listing
June 2013
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