Biomedical subjects
Publications and source records attributed to N S Shenouda.
The crosslink index of the peptidoglycan of intact cell walls of Bacillus subtilis grown in media containing L-[15N]aspartic acid has been determined by a combination of cross-polarization magic-angle spinning 15N NMR and gas chromatography/mass spectrometry. The crosslink index of 62% decreased to 52% when the bacteria were exposed to the antibiotic cephalothin.
The cross-link index of peptidoglycan of intact cell walls of Bacillus subtilis grown in media containing L-[2-13C,15N]aspartic acid has been determined by rotational-echo double-resonance 15N NMR. A cross-link index of 72% decreased to 47% when the bacteria were exposed to the antibiotic cephalosporin C. The fraction of 15N label routed from aspartic acid in the media to glutamic acid in the peptidoglycan peptide stems more than doubled for the cephalosporin-exposed cells, indicating interference with general cell wall nitrogen metabolism by the antibiotic.