山羊脑源性二肽基肽酶III同源物的分离、纯化及特性分析

Isolation, purification and characterization of a DPP-III homologue from goat brain.

作者信息

Dhanda Suman, Singh Hari, Singh Jasbir, Singh Tej P

机构信息

Department of Biochemistry, Kurukshetra University, Kurukshetra 136119, Haryana, India.

出版信息

Protein Expr Purif. 2007 Apr;52(2):297-305. doi: 10.1016/j.pep.2006.10.004. Epub 2006 Oct 25.

DOI:10.1016/j.pep.2006.10.004

PMID:17182254

Abstract

A dipeptidyl peptidase (DPP) from goat brain has been purified. The purified enzyme showed a single band on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). It is a monomer with molecular weight of 69kDa with a pI of 4.5. The K(m) was estimated to be 39microM for Arg-Arg-4-methoxy-beta-naphthylamide (Arg-Arg-4mbetaNA). This enzyme is strongly inhibited by commonly used metallochelators and sulfhydryl reagents. Among various beta-naphthylamides examined, Arg-Arg-4mbetaNA was the most rapidly hydrolyzed substrate. Although, initially it was thought to be the DPP-III but on the basis of its molecular weight and inhibition studies, it was concluded that this enzyme is a functional homologue of DPP-III.

摘要

从山羊脑中纯化出一种二肽基肽酶（DPP）。纯化后的酶在十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）上呈现出一条带。它是一种单体，分子量为69kDa，等电点为4.5。对于精氨酸-精氨酸-4-甲氧基-β-萘酰胺（Arg-Arg-4mbetaNA），其米氏常数（K(m)）估计为39μM。这种酶受到常用金属螯合剂和巯基试剂的强烈抑制。在所检测的各种β-萘酰胺中，Arg-Arg-4mbetaNA是水解最快的底物。尽管最初认为它是DPP-III，但基于其分子量和抑制研究，得出结论：这种酶是DPP-III的功能同源物。