Hydrolysis of the elastase substrate succinyltrialanine nitroanilide by a metal-dependent enzyme in rheumatoid synovial fluid.

摘要: A new type of enzyme hydrolyzing the elastase substrate succinyl-L-alanyl-L-alanine-4-nitroanilide has been found in cell-free rheuma todi synovial fluid. Normal plasma and osteoarthritic fluid contained relatively little enzyme. The pH optimum was 8.0. Unexpectedly, activity not due to leukocyte or any proteinase bound alpha2-macroglobulin. metal-dependent being inhibited by chelating agents but di-isopropylfluorophos phate thiol-blocking reagents. Gel chromatography showed associated with material high molecular weight. On Sepharose 4B two-thirds eluted void volume one-third a position about 106 mol wt. Utracentrifugation that both components were lipid. buoyant density higher weight 1.15-1.22 g/ml., lower 1.2-1.33 g/ml. No latency revealed freezing thawing treatment detergents. nature is discussed. It likely be possibly some kind membrane fragment.