A novel alpha-amino-acid esterase from Bacillus mycoides capable of forming peptides of DD- and DL-configurations.
A novel alpha-amino-acid esterase from Bacillus mycoides capable of forming peptides of DD- and DL-configurations.
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一种来自蕈状芽孢杆菌的新型 α-氨基酸酯酶，能够形成 DD-和 DL-构型的肽。
DOI：
10.1093/oxfordjournals.jbchem.a002949
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发表时间：
2001
影响因子：
2.7
通讯作者：
Y. Tominaga
中科院分区：
文献类型：
--
作者：
A. Sugihara;Y. Shimada;Shigeo Sugihara;T. Nagao;Yomi Watanabe;Y. Tominaga
从拟芽孢杆菌发酵液中分离纯化出一种新的α-氨基酸酯酶，该酶具有合成D-氨基酸多肽的良好性质。该酶由4个39 kDa亚基组成，等电点为7.0，最适温度为47℃，最适pH为7.6。苯甲烷磺酰氟对该酶有较强的抑制作用，而青霉素G和氨苄西林对该酶无抑制作用，提示该蛋白是一种缺乏青霉素结合能力的丝氨酸酶。该酶对D-Phe、D-Trp、D-Tyr和D-Asp(Och(3))甲酯等多种D-和L-氨基酸甲酯均有水解性，但对D-或L-氨基酸酰胺不起作用。Ac-D-Phe-Ome和D-/L-Leu-NH(2)的混合物与酶反应生成Ac-D-Phe-D-/L-Leu-NH(2)和羧基成分的水解物Ac-D-Phe-OH。值得称道的是，该酶不能水解酪蛋白以及包括二苯丙氨酸和二苯丙氨酸等非对映异构体的多肽，这表明该酶不会导致一次形成的多肽的二次水解。这些观察表明，新分离的酶在合成含有D-氨基酸的多肽方面具有潜在的应用价值。
A novel alpha-amino-acid esterase possessing some properties favorable for the synthesis of D-amino acid-containing peptides has been purified from the culture broth of Bacillus mycoides. The enzyme consisted of 4 subunits of 39 kDa, had an isoelectric point of 7.0, and showed its maximum activity at around 47 degrees C and pH 7.6. The enzyme activity was strongly depressed by phenylmethanesulfonyl fluoride, but not by penicillin G or ampicillin, suggesting that the protein is a serine enzyme lacking penicillin-binding ability. The enzyme hydrolyzed a variety of D- and L-amino acid methyl esters with concomitant formation of homooligomers from D-Phe, D-Trp, D-Tyr, and D-Asp(OCH(3)) methyl esters, but it did not act on the D- or L-amino acid amides tested. Incubation of a mixture of Ac-D-Phe-OMe and D-/L-Leu-NH(2) with the enzyme yielded Ac-D-Phe-D-/L-Leu-NH(2) together with Ac-D-Phe-OH, the hydrolysate of the carboxyl component. To its credit, the enzyme failed to hydrolyze casein as well as peptides including diastereomers of diphenylalanine and dialanine, indicating that the enzyme would not cause secondary hydrolysis of once-formed peptides. These observations indicate the potential utility of the newly isolated enzyme for the synthesis of D-amino acid-containing peptides.