Use of Copper-Amino Acid Gomplexing for Determining Amino Acid Esterase Activity.

Abstract

A procedure for the determination of specific proteolytic activity when using an amino acid ester as substrate is described. The method depends on the hydrolysis of the amino acid ester by the enzyme to the free amino acid which is then determined colorimetrically by formation of the blue copper-amino acid complex. The 95% confidence limits for the determination of a single unknown sample of lysine, using a single lysine standard curve, was found to be [plus or minus] 3.5%. The method could be adapted for determining the extent of hydrolysis of other amino acid esters.