Short Communication: Molecular Cloning and Sequence Analysis of C57BL/6 Mouse Contrapsin cDNA

Abstract

Contrapsin is a member of the serpin superfamily and inhibits trypsin much more strongly than αi-antiproteinase. Mouse and rat contrapsins, however, have similarity in sequence to human α1 -antichymotrypsin. In order to test the hypothesis that reactive site regions of contrapsin family evolved under strong selective pressure, cDNA sequence of C57BL/6 mouse contrapsin was determined and compared with that of ICR mouse. The cDNA sequence of C57BL/6 mouse contrapsin was found to contain an open reading frame encoding polypeptide consisting of 418 amino acid residues. The work reported in this paper shows that the reactive site is not hypervariable as compared with the rest of molecule.