Elastolysis of normal and partially cross-linked elastin.

Rate of elastolysis by pancreatic and leukocyte elastases of normal and copper deficient porcine aortic elastins were measured using a conductimetric method. Kinetics obey to Michaelis-Menten model for both substrates and enzymes. KM and Vmax values derived from Lineweaver-Burk plots indicate that, if a near uniformity exists in KM, differences were observed in catalytic rates, kcat increasing approximately 40% for copper deficient elastin elastolysis by leukocyte elastase. This higher susceptibility to proteolysis may have implications for understanding turnover of elastin in tissues.