Studies Of Immobilized Aminoacylase On Resin DEAE-E/H And Separation Of Enzymatic Deacylation Of N-acetyl-DL-methionin

The performance and physical properties of DEAE-E/H resin is systematically studied in the paper, by which the possible influence on the immobilization of aminoacylase is also analyzed. Through the comparison between the resins 8/4/12, 12/4/12 and 4/4/6, the former is chosen as the carrier of immobilization. The adsorption of aminoacylase is investigated and the immobilized enzyme is assessed. Besides, the separation technique of enzymatic deacylation of N-acetyl-DL-methionin is also improved so that the efficiency of separation and the purity of the product are increased. The paper begins with the selection of carriers due to the great effect on the enzyme activity on carrier. Based on the understanding of others' study and investigations, a series of resins of DEAE-E/H were used to adsorb the aminoacylase in which the resin 8/4/12 is more excellent in many aspects, including surface, content of reaction group, distribution of pore and so on. The activity of immobilized enzyme reaches 956U/g at its best. The yield of enzyme activity and the activity of immobilized enzyme reach their peaks when the concentration of enzyme solution is 2.0mg/ml and the optimal time of vibration is 8 hours. A conclusion that the adsorption of aminoacylase on the resin 8/4/12 in single molecule can't be drawn from the adsorption isotherm, furthermore, the cycle adsorption in column is better than oscillation adsorption. Besides, the optimum temperature, pH and other factors on the reaction of immobilized enzyme are investigated and decided. It's sure that the inhibition of substrate is not obvious. As far as the separation of enzymatic deacylation of N-acetyl-DL-methionin is concerned, a new technique is developed that an exchange column of cation resin is adopted resulting to two products, i.e L-Met and Ac-D-Met, and these products acquired high yield of 85% and 75% respectively. Finally, coupling model of two columns is put forward in order to get high efficiency of resolution. In a conclusion, studies on the physical and chemical characters of the resins help to instruct the synthesis of better carrier and provide theory for the improvement of the resolution of amino acids. The optimum reactive conditions of immobilized enzyme and separation of enzymatic deacylation of N-acetyl-DL-methionin are helpful to increase the purity and separation efficiency of products and build solid foundation for industilization.