title: Repetitive region of calpastatin is a functional unit of the proteinase inhibitor.
abstract: A cDNA portion coding for one of the repetitive regions of pig heart calpastatin (107 kDa) was subcloned into E. coli plasmid pUC119 to express the portion of the proteinase inhibitor gene in bacteria. The expressed protein was a chimaeric protein whose calpastatin segment (130 amino acid residues) was fused with an amino-terminus portion (7 amino acid residues) of beta-galactosidase. The chimaeric protein could inhibit proteolytic activity of calpain (Ca2+-dependent cysteine proteinase), and maintained properties of the authentic calpastatin concerning inhibition specificity and heat stability. These findings led us to conclude that the repetitive region is a functional unit of the proteinase inhibitor.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D009206:Myocardium / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D011480:Protease Inhibitors / Q000235:genetics*; D013552:Swine
chemical_list: D002135:Calcium-Binding Proteins; D010446:Peptide Fragments; D011480:Protease Inhibitors; C033668:calpastatin; D004247:DNA; D004262:DNA Restriction Enzymes