Abstract
Pseudocholinesterase (PchE EC 3.1. 1.8) inhibition by capric acid did not occur when the substrate (benzoylcholine) concentration was less than 50mM, but did occur, dose-dependently at higher substrate concentrations, double-reciprocal plots for the fatty acid (FA)-inhibited enzyme reaction of pchE showed that the inhibition was kinetically uncompetitive. It occurred at above room temperature (26-27°C), whereas pchE activity was stimulated at 4°C. The pchE activity was restored in proportion to the increasing concentration (0-1 mM) of human serum albumin (HSA) when it was added to the pchE solution before the capric acid solution, but not when HSA was added after capric acid. This result suggests that for effective restoration of the esterase activity, HSA must react with pchE or capric acid before the interaction of pchE with capric acid.
