Catalytic activity of elastase in reverse micelles.
The activity of porcine pancreatic elastase has been studied in reverse micelles formed by AOT (sodium bis(2-ethylhexyl) sulfosuccinate) in isooctane. For the two substrates succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide and succinyl-L-Ala-L-Ala-L-Pro-L-Leu-p-nitroanilide, the catalytic constant, kcat, in reverse micelles increases with increasing wo until, at high wo, the value of kcat measured in bulk buffer solution is approached (wo = [H2O/]AOT]). In analogy to alpha-chymotrypsin--and in apparent contrast to many other enzymes--elastase does not show a maximum in the kcat-wo profile. Within the wo range of 8 to 35, for both substrates, the Michaelis constant Km (as expressed relative to the total volume of the solution, Km,overall) increases with increasing wo.
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Eidgenössische Technische Hochschule, Institut für Polymere, Zürich, Switzerland.
Walde
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D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D066298:In Vitro Techniques; D007700:Kinetics; D008823:Micelles; D008969:Molecular Sequence Data; D010179:Pancreas / Q000201:enzymology*; D010196:Pancreatic Elastase / Q000378:metabolism*; D013552:Swine
D008823:Micelles; D010196:Pancreatic Elastase