J. Biol. Chem., Vol. 259, Issue 21, 13145-13150, 11, 1984
Purification and characterization of tadpole back-skin collagenase with low gelatinase activity
TA Bicsak and E Harper
A collagenase secreted by tadpole (Rana catesbiana) back-skin explants in
culture has been purified to electrophoretic homogeneity by successive
chromatography on sulfopropyl Sephadex, Sephacryl S-200, collagen
Sepharose, and heparin Sepharose. The purified enzyme has a molecular
weight of approximately 49,000 and an isoelectric pH of 5.0. The enzyme is
more active versus soluble collagen than reconstituted fibrils and exhibits
very low activity against gelatin (specific activities: Type I collagen,
7660 units/mg; Type I gelatin, 66 units/mg). The collagenase obeys simple
Michaelis-Menten kinetics using soluble type I collagen (Km), 0.35 microM;
Vm, 1380 units/mg, at 25 degrees C and pH 7.4) and is inhibitable by
chelating agents specific for transition metals. Methylene blue catalyzes
the photoinactivation of this collagenase, suggesting the presence of
essential histidine, tryptophan, tyrosine, or methionine residues.