Characteristics of neutral proteases present in inflamed human gingiva

The existing forms of neutral proteases present in inflamed human gingiva were examined. Neutral 2 M K Cl extracts of inflamed human gingival tissue were fractionated by gel filtration on Sephacryl S-200 and the fractions were assayed for collagenase, trypsin-, chymotrypsin-, and elastase-like proteases. Apparent molecular weights of 80-85 kDa were obtained for trypsin-, chymotrypsin-, and elastase-like proteases, and 70-75 kDa for latent collagenase. Further fractionation of high molecular weight proteases on Con A-Sepharose revealed that, unlike collagenase, chymotrypsin- and elastase-like proteases, the trypsin-like protease was bound by the affinity column. Native human placental type IV (basement membrane) collagen was degraded by chymotrypsin-like and elastase-like proteases but not by the trypsin-like protease. This degradation was inhibited by phenylmethyl sulfonyl fluoride and EDTA. The serine proteases also degraded efficiently denatured type I collagen. No correlation of the activities of trypsin-like protease and the other proteolytic enzymes was found in extracts of 18 individual gingival specimens. Significant correlation, however, was noted between collagenase and gelatinase. The gingival culture studies showed that, while the highest activity of the trypsin-, chymotrypsin-, and elastase-like enzymes were measured in medium during first days of the culture, collagenase and gelatinase activities increased up to the fourth day of culture and stayed high until the end of the culture. These results suggest that the neutral proteases that may participate in the periodontal tissue destruction are produced by different cell types of gingiva.