来自盘基网柄菌的一种新型二肽基肽酶的纯化与特性分析

Purification and characterization of a novel dipeptidyl peptidase from Dictyostelium discoideum.

作者信息

Choi W S, Fu Q, Jones T H

机构信息

Department of Chemistry, University of San Francisco, CA, USA.

出版信息

Biochem Mol Biol Int. 1999 Mar;47(3):455-64. doi: 10.1080/15216549900201483.

DOI:10.1080/15216549900201483

PMID:10204082

Abstract

A dipeptidyl peptidase (DPP) was purified to homogeneity using lys-ala-beta-naphthylamide, the standard substrate for DPP II. The enzyme is a monomer with a Mr of 70kDa, pl 5.2, and Km 5.0 microM. Its terminal amino acid sequence was XXLLYAIQKRLF and was not identical to that of any known protein. Although initially considered to be a DPP II, the enzyme differed in some properties from classical DPP IIs. It had a pH optimum of 7.9, was not active on X-pro-naphthylamides, the usual substrates of mammalian DPP II, but was active on arg-arg- and asp-arg-naphthylamides, substrates acted on by the DPP III class of enzymes. This enzyme therefore combines properties typical of both DPP II and III and differs from all previously described DPPs. Activity on lys-ala-beta-naphthylamide was most abundant during aggregation and its activity is consistent with processing specific peptides during development.

摘要

利用赖氨酰 - 丙氨酰 -β- 萘酰胺（二肽基肽酶II的标准底物）将一种二肽基肽酶（DPP）纯化至同质。该酶是一种单体，分子量为70kDa，等电点为5.2，米氏常数为5.0微摩尔。其末端氨基酸序列为XXLLYAIQKRLF，与任何已知蛋白质的序列均不相同。尽管最初被认为是一种二肽基肽酶II，但该酶在某些特性上与经典的二肽基肽酶II有所不同。它的最适pH值为7.9，对哺乳动物二肽基肽酶II的常用底物X - 脯氨酰 - 萘酰胺无活性，但对精氨酰 - 精氨酰 - 和天冬氨酰 - 精氨酰 - 萘酰胺有活性，这些是二肽基肽酶III类酶作用的底物。因此，这种酶兼具二肽基肽酶II和III的典型特性，与之前描述的所有二肽基肽酶都不同。在聚集过程中，其对赖氨酰 - 丙氨酰 -β- 萘酰胺的活性最为丰富，且其活性与发育过程中特定肽段的加工过程一致。