Aminolytic reaction catalyzed by D-stereospecific amidohydrolases from Streptomyces spp

作者：Arima Jiro^*; Ito Hitomi; Hatanaka Tadashi; Mori Nobuhiro

来源：Biochimie, 2011, 93(9): 1460-1469.

DOI：10.1016/j.biochi.2011.04.020

• Amidohydrolase
• D-Amino-acid
• Aminolysis
• Streptomyces
• Peptide bond formation

From investigation of 2000 soil isolates, we identified two serine-type amidohydrolases that can hydrolyze D-aminoacyl derivatives from the culture supernatant of Streptomyces species 82F2 and 83D12. The enzymes, redesignated as 82F2-DAP and 83D12-DAP, were purified for homogeneity and characterized. Each enzyme had molecular mass of approximately 40 kDa, and each showed moderate stability with respect to temperature and pH. Among hydrolytic activities toward D-aminoacyl-pNAs, the enzymes showed strict specificity toward D-Phe-pNA, but showed broad specificity toward D-aminoacyl esters. The specific activity for D-Phe-pNA hydrolysis of 82F2-DAP was ten-fold higher than that of 83D12-DAP. As a second function, each enzyme showed peptide bond formation activity by its function of aminolysis reaction. Based on results of D-Phe D-Phe synthesis under various conditions, we propose a reaction mechanism for D-Phe D-Phe production. Furthermore, the enzymes exhibited peptide elongation activity, producing oligo homopeptide in a one-pot reaction. We cloned the genes encoding each enzyme, which revealed that the primary structure of each enzyme showed 30-60% identity with those of peptidases belonging to the clan SE, S12 peptidase family categorized as serine peptidase with D-stereospecificity.

• 出版日期2011-9