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A calcium‐protease activator associated with brain microsomal‐insoluble elements
Author(s) -
Takeyama Yoshihumi,
Nakanishi Hiroyuki,
Uratsuji Yuko,
Kishimoto Akira,
Nishizuka Yasutomi
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80060-6
Subject(s) - microsome , protease , chemistry , calpain , calmodulin , activator (genetics) , affinity chromatography , calcium , biochemistry , differential centrifugation , chromatography , centrifugation , cysteine protease , size exclusion chromatography , enzyme , organic chemistry , gene
A factor which markedly activates Ca 2+ ‐dependent thiol protease (calpain) is associated with Triton X‐100‐insoluble materials, presumably structural elements such as cytoskeletons, of bovine brain microsomal fraction. This factor is extracted with 0.6 M KCl, and purified partially by sucrose density gradient centrifugation and hydroxyapatite column chromatography. The factor appears to be a heat‐stable protein with an approximate M r , of 15000. With casein as substrate this factor activates both calpain I and calpain II severalfold up to more than 10‐ fold without alteration of their affinity to Ca 2+ . Calmodulin is unable to substitute for this factor. A similar factor is associated with human platelet insoluble materials.