IMMOBILIZATION OF PENICILIN G ACYLASE ON POLYACRYLONITRILE FIBER
以聚丙烯腈纤维为载体制备固定化青霉素G酰化酶的研究

The immobilization of Penicillin G Acylase from Bacillus megaterium by glutaraldehyde crosslinking on the partially acid-hydrolyed polyacrylonitrile fiber was studied. When the amount of--NH2 on fiber were 690 mumol/g and the moisture in the fiber was 64%, and the content of enzyme protein immobilized on fiber was more than 100 mg/g. The activity of 2300 IU/g was obtained with 30% of overall yield and 56% of binding efficiency. The immobilization yield was markedly influenced by ratio of the amount of free enzyme used to the weight of the fiber. The half-life of storage stability of immobilized PGA at room temperature was 130 days. The immobilized PGA kept 80% of the initial activity after 20 cycles of operation in 10% of PGK(W/V) in 0.05 mol/L phosphate buffer, pH 8.0, at 37 degrees C and an enzyme load of 150 IU/g(PGK) and 10 g(PGK) for per cycle of operation. The hydrolysis conversion of PGK in the range of 2.5%-12.5% (W/V) were over 98% for the immobilized PGA. The operation stability of immobilized PGA treated with DTT was better than that of immobilized PGA untreated.