Penicillin-insensitive incorporation of D-amino acids into cell wall peptidoglycan influences the amount of bound lipoprotein in Escherichia coli.
Certain D-amino acids, such as D-methionine and D-cystine, were incorporated into cells of Escherichia coli under conditions inhibiting protein and cell wall synthesis. Part of the radioactivity of D-14C-amino acids incorporated into the cells was found in the isolated cell wall peptidoglycan. A covalent linkage between the amino group of the D-amino acids and the peptidoglycan was presumed to be the main cause of the binding of the D-amino acids to peptidoglycan, because the amino group of the D-amino acids in the incorporation product was substituted. Whether the carboxyl terminus was substituted was unknown. The formation of the D-amino acid-peptidoglycan linkage was insensitive to beta-lactam antibiotics such as benzylpenicillin and ampicillin (500 micrograms/ml) and therefore was not due to the reaction of DD-transpeptidation which is involved in the biosynthesis of peptidoglycan. The D-amino acids also strongly inhibited the formation of peptidoglycan-bound lipoprotein in the E. coli cells. The results may suggest the correlation between binding of D-amino acid to peptidoglycan and inhibition of formation of the bound form of lipoprotein.
D000596:Amino Acids / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D007536:Isomerism; D007700:Kinetics; D008074:Lipoproteins / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology*; D010457:Peptidoglycan / Q000096:biosynthesis*
D000596:Amino Acids; D002250:Carbon Radioisotopes; D008074:Lipoproteins; D010406:Penicillins; D010457:Peptidoglycan