Chemical characterization and study of the autodigestion of pure collagenase from Achromobacter iophages

Abstract

Only one collagenase (EC 3.4.24.3) is produced by the non-pathogenic Achromobacter iophagus strain. The chromatography of the crude enzyme on DE-32 cellulose followed by gel filtration on Sephadex G-100 in the presence of 1 M sodium chloride led to the isolation of a homogeneous enzyme. Its specific activity (1.642 μkat/mg) represents the highest value ever obtained for a bacterial collagenase. The amino acid composition of A. iophagus collagenase differs from that of Clostridium histolyticum mainly in the sulfur-containing amino acids. 1 mol of zinc was found for 1 mol of enzyme of molecular weight 104 000. The autodegradation of the A. iophagus collagenase results in the formation of at least three active fractions which can be separated by preparative polyacrylamide gel electrophoresis as well as rechromatography on DE-32 cellulose. They are active towards the synthetic substrate as well as towards the native collagen. The results of ORD have shown that the digestion of the last one occurs in the helical parts of the substrate.