INTERFACIAL ENZYMOLOGY OF GLYCEROLIPID HYDROLASES - LESSONS FROM SECRETED PHOSPHOLIPASES A(2)

Interfacial enzymes operate at an organized interface such as lipid ag gregates in contact with the aqueous phase. The enzyme phospholipase A (2) is a well studied interfacial enzyme, and a discussion of its beha vior at interfaces is the topic of this review. Knowledge gained from studies of phospholipases A(2) can be applied toward the quantitative analysis of other interfacial enzymes. The kinetic analysis of these e nzymes is greatly simplified if one establishes certain experimental c onditions that limit the exchange of enzyme and substrate between diff erent substrate aggregates. With such constraints, the kinetics can be analyzed in terms of classical Michaelis-Menten theory adopted for th e action of enzymes at interfaces. It is also possible to describe oth er enzyme properties such as inhibition and substrate preferences in a meaningful way using formalism that is well known in solution-phase e nzymology.