1974 Volume 27 Issue 4 Pages 267-273
Biosynthesis of pepstatin by Streptomyces testaceus HAMADA et OKAMI was studied.U-14C-L-Alanine and U-14C-L-valine were incorporated into alanine and valine moietiesof pepstatin respectively. U-14C-L-Leucine, U-14C-malonate and U-14C-acetate were incorporatedinto (3S, 4S)-4-amino-3-hydroxy-6-methylheptanoic acid (AHMHA) moiety of pepstatin. Radioactivity of U-14C-L-leucine was located almost exclusively in C3-C8 of AHMHA but not in C1 and C2 and radioactivity of U-14C-malonate was located in C1 and C2 Labeled AHMHA itself was not incorporated into pepstatin. Malonate was incorporated into pepstatin at about 18 times higher rate than acetate. These results indicate that AHMHA is biosynthesized from L-leucine and malonic acid during biosynthesis of pepstatin and suggested that pepstatin biosynthesis proceeds on a multienzyme system in a similar way as in the case of fatty acid synthesis.