Studies on the Mechanism of Lipase Reaction. IV. Action of the Lipase from Chromobacterium on Monomeric p-Nitrophenyl Acetate

The hydrolytic activity of the lipase (EC 3. 1. 1. 3) from Chromobacterium for the monomeric esters was found. The hydrolysis of p-nitrophenyl acetate by the lipase proceeded with three step reaction in which acylation and deacylation processes of the enzyme were involved. The rate limiting step was found to be the acylation. The enzymic hydrolysis was accelerated about 2-fold by the additions of hydrophobic glass beads. Water soluble organic solvents did not activate but inhibit the enzymic hydrolysis and they did not affect significantly on the activating effect by hydrophobic glass beads. It was found that the lipase was adsorbed on the glass beads and once adsorbed enzyme was difficult to desorb. These results were discussed relation to the reaction mechanism of lipolysis by lipase and an assumption was made.