SOME VITAMIN AND AMINO ACID INTERRELATIONSHIPS IN ESCHERICHIA COLI 113-3: I. THE INHIBITORY EFFECTS OF CYSTINE AND CYSTEINESULPHINIC ACID

Abstract

Cystine, cysteinesulphinic acid (CSA), and other closely related sulphur-containing amino acids inhibited growth of Escherichia coli 113-3, particularly in aerobic conditions. The cystine inhibition was completely prevented by aspartic acid, partially reversed by pantothenic acid or β-alanine and slightly reversed by lysine or thiamine. The inhibitory effect of CSA was completely or partially reversed by aspartic acid, lysine, glutamic acid, proline, ornithine, or homoserine. Aspartic acid and glutamic acid appeared to reverse the inhibition competitively while lysine seemed to reverse the inhibition in a noncompetitive manner. Reversal of the inhibitory effect of relatively high concentrations of CSA by lysine was not complete, however, unless methionine was also present. Possible mechanisms of the cystine and CSA inhibition are discussed.