A protease that cleaves proteins on the carboxyl bond of arginine
Clostripain from Clostridium histolyticum has been used as a proteolytic enzyme in perfusate to detect its effect on tube hematocrit. It has also been used in limited proteolysis of DNA polymerase (gp43) of phage T4 (RB69 gp43).
Clostripain from Clostridium histolyticum is composed of two polypeptide chains, with molecular masses of 41.7 kDa and 15.4 kDa. Clostripain has a highly restricted substrate specificity for Arg-Xaa peptide bonds. Therefore, clostripain has been explored as a potential enzyme for protein sequencing purposes. It has also been studied as a catalyst for condensation of pharmaceutically important peptides containing Arg-Pro bonds.
Clostripain is isolated from Clostridium histolyticum callogenase by extraction in pH 6.7 buffer, followed by hydroxylapatite chromatography with a 0.1-0.2 M phosphate gradient, then Sephadex G-75 gel filtration with 0.05M phosphate pH 6.7, dialysis and a second hydroxylapatite chromatography (gradient elution with 0.1M 0.3M phosphate, pH 6.7). It has proteinase and esterase activity and is assayed by hydrolysing N-benzoyl-L-arginine methyl ester. [Mitchell & Harrington J Biol Chem 243 4683 1968, Methods Enzymol 19 635 1970.]
