Cigarette smoke decreases the rate constant for the association of elastase with alpha 1-proteinase inhibitor by a non-oxidative mechanism.
This paper describes a non-oxidative impairment of the biological function of alpha 1-proteinase inhibitor by cigarette smoke. Aqueous solutions of cigarette smoke are able to decrease the rate constant kass for the inhibition of porcine pancreatic elastase by human plasma alpha 1-proteinase inhibitor. The value of kass decreases linearly with the concentration of smoke (from 2.2 X 10(5) M-1 s-1 to 0.6 X 10(5) M-1 s-1). This effect is not due to an oxidation of the inhibitor. When pancreatic elastase is reacted with elastin in the presence of alpha 1-proteinase inhibitor and cigarette smoke solution, elastolysis occurs at a rate nearly identical to that observed in the absence of inhibitor. This effect is due to a smoke-induced decrease in kass. These observations may serve as a model of biological regulation of proteolysis via a change in the rate constant for a proteinase-proteinase inhibitor association. The influence of cigarette smoke on the inhibition of human neutrophil elastase by alpha 1-proteinase inhibitor could not be studied in detail because the enzyme precipitates in the presence of concentrated smoke solution.
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D007700:Kinetics; D009504:Neutrophils / Q000201:enzymology; D010179:Pancreas / Q000201:enzymology; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012907:Smoking; D012995:Solubility; D013552:Swine; D013997:Time Factors; D000515:alpha 1-Antitrypsin
D001798:Blood Proteins; D000515:alpha 1-Antitrypsin; D010196:Pancreatic Elastase