Synthesis and kinetic characterisation of omega-guanidinocarbonic acid ethyl esters as trypsin substrates.

Aliphatic omega-guanidinocarbonic acid ethyl esters of different chain length (C3-C6) were synthesized and characterized as 4-toluenesulfonates. The kinetic parameters of the trypsin-catalyzed hydrolysis indicate that the ethyl ester of delta-guanidinovaleric acid is the most effective substrate in this series. The Km value of this compound is in the same order of magnitude as those of arginine-containing ester substrates like N alpha-benzoylarginine ethyl ester (BAEE). However, kcat is decreased by approximately two orders of magnitude.