Purification of two species of exudate cysteine‐proteinase inhibitors that are acute‐phase reactants in the carrageenin‐induced inflammation in rats

Abstract

Two species of cysteine-proteinase inhibitors (CPIs) have been purified to homogeneity from exudate in the carrageenin-induced inflammation in rats. The exudate CPIs were separated into two forms (named CPI-1 and -2) in affinity chromatography on 4carboxymethyl-papain-Sepharose, the final stage of purification. CPI-1 and -2 gave different mobilities in polyacrylamide gel electrophoresis (PAGE), probably because of different isoelectric points (~14.47 for CPI-1 and ~14.21 for CPI-2). Both CPI-1 and -2 showed immunological identity in double immunodiffusion and same molecular mass of 68 kDa when analysed by SDS-PAGE. These results indicate that CPI-1 and -2 are very similar but distinct CPIs. CPI-1 and -2 are acute-phase reactants and probably represent two species of T-kininogens having inhibitory activity toward cysteine proteinases.