Assay method of enzyme activity

摘要

Novel amine compounds of the formula wherein R1 is lower alkyl and R2 is substituted methyl amino or D-amino acid residue, or a salt thereof. R1 can typically be isobutyl or methyl; and R2 can be methylamino of the formula -NH-CH2-R3 in which R3 is organic, more particularly methyl, ethyl, n-propyl, isopropyl, n-butyl, amyl, p-hydroxybenzyl, 3,4-di-hydroxybenzyl, 5-imidazolemethyl, 3-imidazolemethyl or phenyl. R2 can also be D-amino acid residue of the formula in which one of R4 and R5 is carboxyl and the other is organic, more particularly methylthioethyl, isobutyl, methyl or phenyl, and C* is a D-asymmetric carbon atom. The compounds are useful in an assay method for leucine and aminopeptidase which comprises reacting a substrate amide as above, or a salt thereof, with a sample for leucine aminopeptidase assay, incubating the reaction product produced thereby, and measuring the thus-consumed oxygen or liberated hydrogen peroxide.