A latent collagenase from rheumatoid synovial fluid. Purification and partial characterization.

1. A latent collagenase (EC 3.4.24.3) has been isolated from rheumatoid synovial fluids and purified by (NH4)2SO4 precipitation and column chromatography, utilising Sephadex G-150, DEAE Sephadex A-50 and Sephadex G-100 superfine grade. 2. The final preparation activated by trypsin (EC 3.4.21.4) had a specific activity against thermally reconstituted collagen fibrils of 259 micrograms collagen degraded/min per mg enzyme protein, representing a nearly 800-fold increase over that of the original rheumatoid synovial fluid. 3. The latent collagenase preparation can be activated by trypsin and to some extent by HgCl2 but not by 3 M NaSCN, 3.5 M NaCl, 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) or p-chloromercuribenzoate. 4. Inhibition studies and the acrylamide gel electrophoretic pattern of collagen degradation products showed that the trypsin-activated enzyme has the essential features of a neutral collagenase. 5. The molecular weights, determined by calibrated gel filtration, were 52 000 and 43 000 for the latent and the activated enzyme, respectively. 6. The nature of the latency of synovial fluid collagenase is discussed.