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Some antagonisms between naturally occurring amino acids, peptides and keto acids in adaptive enzyme synthesis and growth

1958; Elsevier BV; Volume: 73; Issue: 2 Linguagem: Inglês

10.1016/0003-9861(58)90285-6

1096-0384

Eddie Ball, Jean S. Humphreys, William Shive,

Chemical Synthesis and Analysis

Glycylvaline and α-ketoisovaleric acid replace valine for synthesis of the adaptive malic enzyme in Lactobacillus arabinosus as well as for growth of the organism. Isoleucine, glycylisoleucine, and α-keto-β-methylvalerate competitively inhibit the utilization of valine, glycylvaline, and α-ketovalerate, respectively, for both synthesis of the adaptive malic enzyme and growth, but valine and its derivatives are each inhibited by the corresponding analog, but not by the other two derivatives of the analog. Each competitive inhibition involving the keto acids, peptides, or free amino acids is independent of the other two competitive inhibitions; so the utilization of keto acid and peptide does not involve the inhibited site of utilization of the free amino acid. The formation of an active form of valine for enzyme synthesis by separate pathways from keto and amino acid and peptide affords a plausible explanation for these results.