Immobilization of penicillin G acylase onto chemically grafted nylon particles

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.