Studies on oral enzymes. VI. Hydrolysis of periodontal collagen by plaque enzyme extract

Elevated conversion of alpha-2-macroglobulin to the complexed form in gingival crevicular fluid from adult periodontitis patients

The broad spectrum protease inhibitor, alpha 2-macgrolobulin (alpha 2M), is one of the host's principal regulators of both endogenous and exogenous proteases and is likely to have an important role in the regulation of proteolytic activity at inflammatory sites. We have determined the amount of complexed (com alpha 2M) and total alpha 2M (tot alpha 2M) in gingival crevicular fluid (GCF) harvested from shallow and deep sites in adult periodontitis (AP) patients (n = 21). An ELISA technique was developed to measure both forms of alpha 2M in the same sample utilizing a monoclonal antibody (MAb) specific for the complexed form. In addition, protease activity towards human serum albumin (Prot1), transferrin (Prot2) and N alpha-benzoyl-L-arginine 7-amido-4-methylcoumarin-hydrochloride (BAAMc; Prot3) were determined in a second GCF sample from the same site. Plasma alpha 2M concentrations were only positively correlated (p = 0.0163) with GCF tot alpha 2M from highly inflamed sites. We observed a significant positive correlation between tot alpha 2M and proteolytic activity in GCF from deep sites but not from shallow sites (Prot1: p = 0.002; Prot2: p = 0.005). A similar correlation between tot alpha 2M and proteolytic activity was found at highly inflamed sites (Prot1: p = 0.014; Prot2: p = 0.002). A very high proportion of the tot alpha 2M in GCF was in the complexed form at both shallow (71.14% +/- 29.13) and deep sites (68.17% +/- 28.5) Com alpha 2M was positively correlated with proteolytic activity only in deep sites (Prot1: p = 0.015; Prot2: p = 0.031). Our results suggest that the concentration of tot alpha 2M in the gingival crevice is positively associated with the amount of proteolytic activity at the site and that protease activities in GCF may only partly explain the high percentage conversion alpha 2M to the complexed form. The high level of alpha 2M inactivation in GCF from AP patients reported here may have significance not only in view of its role as a broad spectrum protease inhibitor but also through the differential effects of native vs complexed alpha 2M on the regulation of immune responses.

Proteases and their inhibitors in chronic inflammatory periodontal disease

This article reviews the current knowledge of the sources, function and interactions of proteolytic enzymes and their inhibitors in chronic inflammatory periodontal disease. Proteolytic tissue degradation is a typical phenomenon in chronic inflammatory periodontal disease. The proteolytic enzymes can be both host- and bacteria-derived. The proteases of the inflammatory cells are aimed for digestion of bacteria, enhanced locomotion through connective tissue, demarcation of the site of infection and tissue remodeling. Uncontrolled release of proteases in inflammation causes self-digestion and tissue destruction. The potential of the bacterial proteases in degradation of connective tissue is not yet known. Biochemical and immunologic mediators of inflammation are released by proteolytic reactions. Immunoglobulin-cleaving proteases present a specific mechanism in perturbation of host defenses. The 2 main protease inhibitors in serum, alpha-1-antitrypsin and alpha-2-macroglobulin, are also present in the gingival tissue fluid guarding the function of proteases. It has been suggested, although not confirmed, that deficiency in serum protease inhibiting capacity could be correlated with susceptibility to periodontal disease. Mucous secretions contain local low molecular weight protease inhibitors, but their possible rôle in saliva is not known. Bacteria-derived, antiproteolytic short peptides may prove to be useful in pharmacological control of tissue destruction at inflammatory sites.

The interaction of collagenase with hydroxyapatite and related materials and enzymatic properties of the adsorbed enzyme

The commercial collagenase from Clostridium histolyticum was adsorbed on hydroxyapatite, on bovine femur shaft and on enamel and dentin powders. The substrate specificity of the adsorbed enzyme tested, with chromophore substrate, azocoll and native collagen, differed from that obtained with the soluble enzyme. The adsorption and the substrate specificity was also dependent on the adsorbent used. A pretreatment of hydroxyapatite with chondroitin sulphate, hyaluronate and DNA lowered the adsorption of collagenase. Phosphate ion caused desorption of the enzyme from hydroxyapatite. Sodium fluoride caused partial desorption of the enzyme from hydroxyapatite and enamel and dentin powders. Colangenase adsorbed on root surfaces of teeth liberated hydroxyproline containing material.