Degradation of type IV (basement membrane) collagen by a proteinase isolated from human polymorphonuclear leukocyte granules

A serine esterase with potent proteolytic activity against native bovine lens capsule type IV collagen was isolated and purified from extract of human polymorphonuclear leukocytes (PMN). The type IV collagenolytic activity co-purified with N-t-benzyloxycarbonyl-L-alanine nitroanilidase, and was inhibited by phenylmethanesulfonyl fluoride and N-acetyl-Ala-Ala-Ala-Ala chloromethyl ketone. In addition, the purified enzyme had elastolytic activity, reacted with a specific antibody to PMN elastase, and, therefore, appeared to be identical with this enzyme. A simple, reproducible assay for the detection of type IV collagenase activity using insoluble bovine anterior lens capsule collagen was defined. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the enzyme released large molecular weight peptides (greater than 30,000) from the insoluble substrate. The enzyme was also active against native, pepsin-solubilized type IV collagen; five reaction products could be identified. These data suggest that PMN elastase may be involved in the degradation of basement membrane collagen in physiologic and pathologic states.