Deacylation rate constants of acylated human and porcine plasmins

Deacylation rate constants, k3, were measured for the human acyl-plasmins which contain in the acyl portion, RCO, the R groups methyl, cyclohexyl, p-nitrophenyl, isobutyl, trans-isopropenyl, phenyl, alpha-naphthyl, anisoyl and p-guanidinophenyl. Values of k3 were also determined for the porcine acyl-plasmins which have R = methyl, cyclohexyl, phenyl, anisoyl and p-guanidinophenyl. In general, for both the human and porcine acyl-plasmins, k3 decreased as the electron-donating ability of the acyl group increased. At 25 degrees C, the human acyl-plasmin with R = methyl has the highest k3, 1.06 +/- 0.05 X 10(-2) s-1, and the porcine acyl-plasmin with R = p-guanidinophenyl the lowest k3, 1.4 +/- 0.1 X 10(-6) s-1.