Influence of water miscible organic solvents on orange flavedo peptide amidase

Due to the broad substrate spectrum and stability in some water-miscible organic solvents, the peptide amidase from orange flavedo was found to be a suitable enzyme for experiments in water-miscible organic solvents. Immobilization and the kind of organic solvent had no significant influence on the kinetic data while the polarity of the substrate caused a great difference in the apparent Km values. The results are explained by inadequate partition of the substrate between the microenvironment of the enzyme and the reaction solution.