As a model of Serine hydrolase

the p olycondensates of salicylic acid

formaldehyde and methyl

n-propyl

n-hexyl

or n-lauryl amine were prepared by Mannich's condensation. The catalytic activities of the above polymers for hydrolysis

of p-nitrophenyl acetate (PNPA)

were investigated. It was found kinetically that the rate of hydrolysis of PNPA increases with increasing length of the alkyl groups in the side-chain of the polymers. Hydrolysis of PNPA catalyzed by the polycondensate of salicylic acid

formaldehyde and n-laurylamine proceeded by the simple Michaelis-Menten type mechanism. The kinetics parameters were obtained as: Km=6.7×10-5M

and Vmax=2.07×10-7M·min-1.