曲霉酸性羧肽酶的C末端肽基-L-脯氨酸水解酶活性

C-Terminal peptidyl-L-proline hydrolase activity of Aspergillus acid carboxypeptidase.

作者信息

Ichishima E, Takeuchi M, Yasuda R, Suzuki Y, Kobayashi S

出版信息

J Biochem. 1977 Jun;81(6):1733-7. doi: 10.1093/oxfordjournals.jbchem.a131633.

DOI:10.1093/oxfordjournals.jbchem.a131633

PMID:19444

Abstract

Aspergillus saitoi acid carboxypeptidase hydrolyzed C-terminal peptidyl-L-proline bonds and released the C-terminal proline from Z-Gly-Pro-Leu-Gly-Pro and Z-Gly-Pro at pH 3.3. Proline liberated by the enzymic reaction was measured by a sensitive colorimetric ninhydrin method in glacial acetic acid at 513 nm. A Km value of 1.0 mM and a kcat value of 0.09 s-1 for Z-Gly-Pro-Leu-Gly-Pro hydrolysis, and a Km value of 5.0 mM and a kcat value of 0.0045 s-1 for Z-Gly-Pro hydrolysis were calculated from Lineweaver-Burk plots.

摘要

斋藤曲霉酸性羧肽酶在pH 3.3时可水解C端肽基-L-脯氨酸键，并从Z-甘氨酰-脯氨酰-亮氨酰-甘氨酰-脯氨酸和Z-甘氨酰-脯氨酸中释放出C端脯氨酸。通过灵敏的比色茚三酮法在513 nm波长下于冰醋酸中测定酶促反应释放的脯氨酸。根据Lineweaver-Burk图计算得出，Z-甘氨酰-脯氨酰-亮氨酰-甘氨酰-脯氨酸水解的Km值为1.0 mM，kcat值为0.09 s-1；Z-甘氨酰-脯氨酸水解的Km值为5.0 mM，kcat值为0.0045 s-1。