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 diamine (HMDA). The aminoalkylated particles were activated with glutaraldehyde and finally, penicillin G acylase (PA) was immobilized to these activated particles. he 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 improved 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.