Clostripain (Endoproteinase-Arg-C)

Clostripain is a sulfhydryl proteinase associated with collagenase and isolated from Clostridium histolyticum. It is highly specific for the carboxyl peptide bond of arginine.

Characteristics of the Enzyme from Clostridium histolyticum

Enzymatic Reaction (image will open in a new window)

Molecular Weight: Gilles et al. (1979) indicate it to be composed of two chains with relative molecular masses of 45,000 and 12,500.

Composition: The amino acid composition is described by Mitchell and Harrington (1968). Studies on the active site are reported by Porter et al. (1971).

Optimum pH: pH 7.4-7.8 (activity against a-benzoyl-arginine ethyl ester).

Isoelectric point: 4.8-4.9 (8°C.)

Inhibitors: Oxidizing agents and sulfhydryl reactants; also Co²⁺, Cu²⁺, Cd²⁺, and heavy metal ions. Citrate, borate, and Tris anions partially inhibit. TLCK reacts with active site. (Porter, et al., 1971).

Activators: Sulfhydryl requirement -- dithiothreitol, cysteine, or other reducing agents. Calcium ion is essential.