The tryptophanase-tryptophan reaction

Abstract

Serine and alanine had an inhibitory effect upon indole production from trypto-phan by Escherichia coli. This effect was not a simple relation between the tryptophan and serine conc, and only held when the enzyme was saturated with tryptophan. Fildes''s (1945) finding that there was no evidence of tryptophan synthesis from indole and serine using cells of E. coli was confirmed. Using partition chromatographic analysis and retarding the reaction with mepacrine, alanine was detected as an intermediate; under similar conditions the presence of the serine was not detected.