Determination of the esterase activity of serine proteinases using synthetic substrates

: The authors suggest a highly sensitive rapid and simple method for measuring esterase activities of bovine pancreatic chymotrypsin, human neutrophilic cathepsin D, and elastase, and of human blood serum chymotrypsin-like esterase and elastase-like esterase activities, with fluorogenic synthetic ethers, amino acid derivatives, employed as substrates: N-benzoxycarbonylphenylalanine 4-methylumbelliferyl ester (Z-Phe-OMC) and tret-butyloxycarbonyl-1-alanine 4-methylumbelliferyl ester (BOC-Ala-OMC).