Kinetics of the inhibition of human pancreatic elastase by recombinant eglin c. Influence of elastin.

摘要: Recombinant eglin c is a potent reversible inhibitor of human pancreatic elastase. At pH 7.4 and 25 degrees C, kass. = 7.3 x 10(5) M-1.s-1, kdiss. 2.7 10(-4) s-1 Ki 3.7 10(-10) M. Stopped-flow kinetic indicate that the formation stable enzyme-inhibitor complex not preceded by fast pre-equilibrium or latter has dissociation constant greater than 0.3 microM. The elastase-eglin much less at 5.0 where 1.1 10(-2) 10(-8) activation energy for 43.9 kJ.mol-1 (10.5 kcal.mol-1). increases between 8.0 remains essentially up to 9.0. This pH-dependence could be described simple ionization curve. Both alpha 2-macroglobulin 1-proteinase are able dissociate complex, as evidenced measurement enzymic activity 2-macroglobulin-bound elastase polyacrylamide-gel electrophoresis mixtures complex. rough estimate obtained with experiment (1.6 s-1) was same order magnitude measured progress curve method. Eglin strongly inhibits solubilization aorta elastin extent inhibition whether added suspension preincubated 3 min before addition c. However, efficiency sharply decreases if reacted more prolonged periods.