Requirements of different subdomains of calpastain for calpain inhibition and for binding to calmodulin-like domains

Hong Ma, Hong Qiong Yang,, Emiko Takano,, Woon Joo Lee,, Masakazu Hatanaka, Masatoshi Maki

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Calpain requires Ca2+ for both proteolysis of its substrates and interaction with its endogenous inhibitor, calpastatin. The mechanism of inhibition of calpain by calpastatin has remained unsolved, although Nishimura and Goll [J. BioL Chem. 266, 11842-11850 (1991)] reported that autolyzed calpain fragments containing calmodulin-like domains (CaMLDs) bound to an immobilized calpastatin column. We investigated the correlation between CaMLD-binding and calpain inhibition using immobilized columns of geneengineered CaMLDs derived from the human t-calpain large subunit and various recombinant calpastatin mutants. Among the four internally repetitive inhibitory domains of calpastatin, each having conserved regions A, B, and C, only domains 1 and 4 showed the binding activity. The region B deletion mutant of domain 1, retaining the CaMLD-binding ability, no longer had the calpain inhibition activity, and became susceptible to proteolysis. In contrast, a synthetic oligopeptide of region B with moderate calpain inhibition activity did not bind to the column. Domain 3 acquired the binding ability on substitution of region A with that of domain 1. These results suggest that calpain inhibition and binding to the CaMLDs are not correlated or mediated by different subdomains of calpastatin. 1993

Original languageEnglish (US)
Pages (from-to)591-599
Number of pages9
JournalJournal of Biochemistry
Issue number5
StatePublished - May 1993

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Requirements of different subdomains of calpastain for calpain inhibition and for binding to calmodulin-like domains'. Together they form a unique fingerprint.

Cite this