Sensitive assays for trypsin, elastase, and chymotrypsin using new fluorogenic substrates.

Gillian Beamer, Samuel Major, Bikul Das, Antonio Campos-Neto

Index: Anal. Biochem. 78 , 47, (1977)

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Abstract

Sensitive fluorogenic substrates for trypsin, chymotrypsin, and elastase were prepared. These substrates are amides of an acyl amino acid or peptide with 7-amino-4-methylcoumarin (AMC). The substrates with their respective K cat K m ratios given in parentheses are: for chymotrypsin, glutaryl-Phe-AMC (78) and Ala-Ala-Phe-AMC · TFA (1660); for trypsin, benzoyl- dl-Arg-AMC (800) and Carbobenzoxy (Cbz)- l-Arg-AMC (5300); for elastase, N-acetyl-Ala-Ala-Pro-Ala-AMC (15,000). The detection limits obtained by using the best substrates and short incubation times are: chymotrypsin, 25 ng; trypsin, 5 ng; and elastase, 2 ng.