Abstract
7-Keto-8-aminopelargonic acid synthetase (KAPA synthetase) which catalyzes the formation of KAPA from pimelyl CoA and L-alanine, and is involved in biotin biosynthesis, was partially purified from a cell-free extract of Bacillus sphaericus by a procedure involving ammonium sulfate fractionation, protamine treatment, and DEAE-cellulose column chromatography. The reaction product was bioautographically confirmed to be KAPA. Some properties of the enzyme were also investigated. Among the amino acids, only L-alanine was active as a substrate, condensing with pimelyl CoA. The reaction required pyridoxal phosphate but the other vitamin B6 compounds were inert. Typical inhibitors of pyridoxal phosphate enzymes showed marked inhibition to the reaction. Various amino acids such as L-cysteine, glycine, D-alanine, L-serine, L-histidine, and D-histidine were also found to be inhibitory.
