心脏高分子量钙调蛋白结合蛋白与钙蛋白酶抑制蛋白I和钙蛋白酶抑制蛋白II同源。

Cardiac high molecular weight calmodulin-binding protein is homologous to calpastatin I and calpastatin II.

作者信息

Singh Nisha, Shrivastav Anuraag, Olson Doug, Lakshmikuttyamma Ashakumary, Ross Andrew, Parr Tim, Bardsley Ronald G, Sharma Rajendra K

机构信息

Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, 103 Hospital Drive, Saskatoon, Saskatchewan, Canada S7N 0W8.

出版信息

Biochem Biophys Res Commun. 2008 Aug 29;373(3):387-91. doi: 10.1016/j.bbrc.2008.06.040. Epub 2008 Jun 20.

DOI:10.1016/j.bbrc.2008.06.040

PMID:18572013

Abstract

Calpastatin is an endogenous inhibitor of calpain, which has been implicated in various physiological and pathological processes. In the present study we determined the molecular and inhibitory properties of HMWCaMBP, calpastatin I, and calpastatin II. Western blot analysis with antibodies raised against either full length HMWCaMBP or internal peptides that are common to all isoforms showed that all three homologs have common antigenic epitopes. However, additional Western blot analysis with N-terminal specific antibodies showed that all three proteins are different at the N-terminal end. HMWCaMBP is clearly different from two other homologues, calpastatin I and II, at the N-terminal end. In addition, HMWCaMBP also showed the same affinities for m-calpain as calpastatin I and calpastatin II. Our findings suggest that HMWCaMBP is the homolog of calpastatin and may be a CaM-binding form of calpastatin.

摘要

钙蛋白酶抑制蛋白是钙蛋白酶的一种内源性抑制剂，它与多种生理和病理过程有关。在本研究中，我们确定了高分子量钙调蛋白结合蛋白（HMWCaMBP）、钙蛋白酶抑制蛋白I和钙蛋白酶抑制蛋白II的分子特性和抑制特性。用针对全长HMWCaMBP或所有同工型共有的内部肽段产生的抗体进行的蛋白质印迹分析表明，所有三种同源物都有共同的抗原表位。然而，用N端特异性抗体进行的额外蛋白质印迹分析表明，所有三种蛋白质在N端是不同的。HMWCaMBP在N端明显不同于其他两种同源物，即钙蛋白酶抑制蛋白I和II。此外，HMWCaMBP对m-钙蛋白酶的亲和力与钙蛋白酶抑制蛋白I和钙蛋白酶抑制蛋白II相同。我们的研究结果表明，HMWCaMBP是钙蛋白酶抑制蛋白的同源物，可能是钙蛋白酶抑制蛋白的一种钙调蛋白结合形式。