Collagenase enzymes from Clostridium: characterization of individual enzymes

Four collagenases have been purified to apparent homogeneity from extracts of Clostridium histolyticum and partially characterized. The four purified enzymes are devoid of hydrolytic activity against casein and the synthetic substrate, benzolyarginine naphthylamide, but all retain activity against native collagen. The enzymes are initially spearated by isoelectric focusing where three of the enzymes show distinct isoelectric points: collagenase I = 5.50, collagenase II = 5.65, and collagenases IIIa and IIIb = 5.90-6.00. Collagenases IIIa and IIIb can be subsequently separated on diethylaminoethylcellulose. The four purified enzymes show single bands upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Calibration of the molecular weights on the basis of migration distance shows a marked dependence on gel porosity. At high acrylamide concentration, collagenases I, II, and IIIa appear to converge to a limiting molecular weight congruent to 81 000, while collagenase IIIb has a distinctly lower value congruent to 72 000. The similarity between these molecular weight values and those derived from the sedimentation and diffusion coefficients of the native enzyme indicates that each collagenase is a single polypeptide chain. All of the collagenases have comparable catalytic activities against a series of natural and synthetic substrates and are immunologically cross-reactive. Although all four enzymes are evident upon initial electrofocusing of the crude extract, it is possible that the multiplicity of forms is, at least in part, a consequence of lysis following initial secretion from the cell.