Nylon particles, grafted with diethylene glycol dimethacrylate (DGDA) using
potassium persulphate as initiator, were treated with hexamethylene diamin
e (HMDA). The aminoalkylated particles were activated with glutaraldehyde a
nd finally, penicillin G acylase (PA) was immobilized to these activated pa
rticles.
Both the conditions of the aminoalkylation- and the immobilization process
were optimized. The hydrolysis of cephalexin was used as model conversion.
The retention of activity of the immobilized enzyme was 12%. This value imp
roved to 30% by adding phenyl acetic acid (PAA), as active-site protecting
agent, to the enzyme solution. The results suggest formation of multi-point
attachment between the enzyme and the matrix. (C) 2000 Elsevier Science B.
V. All rights reserved.