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Biomedical subjects

S Shoukry

Publications and source records attributed to S Shoukry.

9 recordsLinked to original sources
PubMed1991

A new technique for determining the distribution of N7-methylguanine using an automated DNA sequencer.

We have developed a method to determine rapidly the sequence specificity of DNA alkylation resulting from chemical treatment. The utility of this approach is demonstrated here in a study of the sequence specificity of alkylation by dimethylsulphate (DMS). The method is independent of the sequence chosen and makes use of the polymerase chain reaction (PCR) to generate a fluorescently labelled DNA target. In this study, a 302 bp segment of the Escherichia coli lacI gene was amplified and the product purified by liquid chromatography on a Mono Q column. This DNA was alkylated with DMS and treated with hot piperidine to produce single-strand breaks at sites of N7 alkylation. The distribution of the break points, and hence the position and extent of alkylation, were determined on an Applied Biosystems 370A automated DNA sequencer.

Alkylation↗
PubMed1979

Staphcoccomycin, a new basic macrolide antibiotic.

Staphcoccomycin (SCM) is a new member of the basic macrolide family of antibiotics which was isolated from the fermentation broth of Streptomyces sp. AS-NG 16. The production, purification and determination of physical and chemical properties of this novel metabolite have been completed. Comparison of the mass fragmentation patterns of SCM and its peracetate with those of angolamycin peracetate suggested a des-mycarosyl derivative of angolamycin. Moreover, the molecular ion peak (m/e 771) corresponded to C39H65NO14 and the 1H-NMR of SCM was also consistent with the proposed structure.

Animals↗
PubMed1977

Kuwaitimycin, effect on synthesis of lipids in Bacillus subtillis cells.

The effects exerted by kuwaitimycin on synthesis of lipids as well as some metabolic activities of Bacillus subtilis were studied. The antibiotic not only arrested the inocrporation of 14C-acetate into the microbial lipids but also altered the fatty acids pattern, contents of i-C 15, a-C 15, i-C 17 and a-C 17 WERE MARKEDLY REDUCED, CONCOMITANT WITH AN INCREASE IN THE CONtents of i-C 14 AND N-C 14. Moreover, the rates of synthesis of phospholipids were decreased by the drug, especially that of phosphatidyl ethanolamine.

Anti-Bacterial Agents↗
PubMed1976

4,4'-isopropylidine-bis(2-isopropyl)phenol, a new inhibitor for cell wall formation of Bacillus subtilis.

4,4'-Isopropylidine-bis[2-isopropyl]phenol was found to possess antimicrobial activity against gram-positive bacteria and some fungi, whereas it had no effect on gram-negative organisms. The drug has a potent inhibitory action on the synthesis of cell wall mucopeptides of Bacillus subtilis by inhibiting the enzyme d-glutamate ligase, which is responsible for the incorporation of d-glutamic acid into uridine 5'-diphosphate-muramyl-l-alanine. The drug had a weak lytic effect on protoplasts and inhibited protein synthesis, whereas no significant effect on the synthesis of deoxyribonucleic acid and ribonucleic acid was found.

Alanine↗
PubMed1976

The mode of action of ASK-753 on Bacillus subtilis.

The mode of action of ASK-753 on Bacillus subtilis was examined. Unlike proper sideromycin antibiotics ferrioxamine B failed to antagonize the antimicrobial effects of ASK-753. The antibiotic could inhibit the biosynthesis of nucleic acids; effect on the RNA was more pronounced. ASK-753 affected the stability of prelabelled DNA of B, subtilis in growing or resting cultures; the effect on the latter was more pronounced. Lysis of B, subtilis protoplasts could be attained at 30 degrees C but not at 4 degrees C which excludes a possible detergent affect of the drug. The drug exerted a potent inhibiting influence on protein synthesis by arresting the activity of lysyl-tRNA synthetase and thus could prevent the incorporation of 14C-lysine.

Anti-Bacterial Agents↗
PubMed1975

On the effect of N-methyl-bis (3-mesyloxypropyl) amine hydroxychloride on Bacillus subtilis cells.

N-Methyl-bis (3-mesyloxypropyl)amine hydrochloride is now in use as an antitumer drug. In view of its activity against some bacteria the present work was conducted to study its mode of action of Bacillus subtilis. The compound was found to induce irreversible damage to bacterial DNA whereas its effect on RNA was temporary and depending on maintenance of effective concentrations of the compound.

Antineoplastic Agents↗