Biochemistry of Amino Acids - A. Majster 1961

General Biochemistry and Physiology of Amino Acid Metabolism
Racemization of Amino Acids
Racemization of Threonine

Data have been obtained indicating the interconversion of L- and D-isomers of Threonine in Escherichia coli Cells [384]. Upon incubation of D-threonine with an E. coli extract, adenosine triphosphate (or adenylic acid), phosphate buffer, and an L-threonine deaminase preparation (from Clostridium welchii), ammonia is formed. In the absence of deaminase, L-threonine is formed, which is determined microbiologically using an E. coli mutant strain requiring it. In the same system, the disappearance of L-threonine is observed when it is added to the extract instead of the D-isomer. This reaction requires a more detailed study. Its mechanism appears to be complex, since unusual Cofactors are involved, and also because the interconversion of L- and D-threonine requires the inversion of both centers of Asymmetry in the molecule of this amino acid:

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Last update: 06/08/2026

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