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Properties of calpastatin forms in rat brain
Author(s) -
Melloni Edon,
De Tullio Roberta,
Averna Monica,
Tedesco Ilaria,
Salamino Franca,
Sparatore Bianca,
Pontremoli Sandro
Publication year - 1998
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/s0014-5793(98)00724-8
Subject(s) - calpastatin , calpain , inhibitory postsynaptic potential , proteolysis , recombinant dna , chemistry , biochemistry , microbiology and biotechnology , gene , biology , enzyme , neuroscience
Four recombinant calpastatin forms, deduced from rat brain mRNAs and differing in the number of inhibitory repetitive domains from zero to four, were expressed and characterized for their inhibitory efficiency on μ‐ and m ‐calpain. Although the most effective one is a truncated calpastatin form composed of the N‐terminal region (domain L) and a single inhibitory domain, all inhibitors are more active against μ‐calpain, but are preferentially degraded and inactivated by m ‐calpain. The protein form composed exclusively of a domain L is deprived of any inhibitory activity but prevents inhibition of calpain by the other calpastatin forms, indicating that this calpastatin region could be relevant in the recognition of the proteinase. A calpastatin form having molecular properties similar to those of the recombinant truncated calpastatin, has also been found in rat brain. It does not derive from proteolysis of a higher molecular mass precursor. The expression of multiple calpastatin forms may be relevant for the specific modulation of the different calpain isozymes normally present in a single cell type.