Saccharomyces cerevisiae 由来 D-アミノ酸アセチルトランスフェラーゼの精製と性質

Some properties of D-amino scid acetyltransferase purified from Saccharomyces cerevisiae were investigated. The enzyme was purified to homogeneity by ammonium sulfate fractionation, column chromatographies on DEAE-Toyopearl 650M, Sephacryl S-200, QAE-Toyopearl 550C and affinity chromatography with D-glutamate as a ligand. The molecular weight was estimated to be about 53,000 by gel filtration. Relative molecular mass studies indicated that the enzyme was a monomer structure. The purified enzyme had an optimum pH of 8.4 and an optimum temperature of 40C. The Km values of the purified enzyme determined with tryptophan and acetyl-CoA were 4.5 * 10 -3M, respectively. The 20 residues of N-terminal amino acid sequence were analyzed.