Simultaneous determination of esterase and peptidase activities of elastase.

Abstract

1. Synthetic substrates conventionally used can give either the esterase or peptidase activity of elastase separately, but simultaneous determination of both activities using one substrate has not previously been attempted. 2. In this work, the esterase and peptidase activities of elastase were determined simultaneously. Esterase activity can be expressed in terms of formation of Ala3 and peptidase activity can be expressed in terms of formation of Ala2 with Ala3OMe as the substrate : Ala3OMe is split into Ala3+MeOH by the esterase activity of elastase and into Ala2+Ala-OMe by the peptidase activity. 3. The present method differentiates the esterase or peptidase activities of other enzymes from those of elastase. Ala3OMe is split to Ala3, and then to Ala2+Ala in a stepwise manner by other proteases such as collagenase and pronase E. 4. Trypsin and chymotrypsin enhanced both the peptidase activity and esterase activity of elastase in parallel. 5. The substrate, suc Ala3NA has been used conventionally to determine elastase activity, and the results with suc Ala3NA and Ala3OMe showed a good correlation.