Study On Immobilized Phospholipase A₁,Enzymatic Modificaton Of Lecithin And Microemulsifiable Properties Of Lysolecithin

PLA1(phospholipase A1) was immobilizied by the methods of covalention and microcapsule. There ared studied the meathods of immobilization immobilized carriers and dependence between recovery of enzyme activity and conditions of immobilizied PLA1. The results shows that the condition of microcapsule for immobilizied PLA,are the chitosan (DD%=85%,Mw=1.3 105) concentration-1.5%, alginate concentration-3% glutaradehyde concentration - 1% Ca2+ concentration - 0. 5moL/L pH=6, Finally getting recovery of enzyme activity-81% and T1/2=350h.When immobilized PLAi, inhibitor, phosphate can couple amine residues which is important for catalysis or maintaining protein structure. Therefore, it can protect amine groups of activing site by binding between glutaradehyde and inactive groups of amine so that increasing activity retention of immobilized enzyme. In addtion, it is proved that phosphate is a competive inhibitor of PLA1,and by the means of making chart getting the Ki.Chitosan alginate loaden enzyme have prominent effect for activity of immobilized enzyme by orthogonal experimental design, and getting optimum condition . IR spectra analyz chitosan/alginate microcapsule, and study on the inner structure of microcapsule by the ways of SEM which shows that it have regular micro-hole which have very large inner superficial area. Consequently , microcapsule can enhance activity of immobilized enzyme, increase interface area of reaction of lecithin and PLA1.There are of modified lecithin by free PLA1 and immobilized PLA1 ?The optium reaction condition are temperature(50), pH(8.0), 4mL2% lysolecithin reaction time (10h) by immobilized PLA1. In addition, lysolecithin is the most prominent factor for modified lecithin.There are study on the part of qualities of lysolecithin and the results that lysolecithin have better qualities of wetting ability and emulsionstability than that of phospholipid. Meanwhile , it has been analyzed by IR and physical-chemical properities of lysolecithin.Lysolecithin having higher HLB, can form system o/w easily, which is thermodynamically stable colloidal system. Preparing system of lysolecithin-based microemulsion containing cholesterol, was made up of cholesterol / lysolecithin / n-propanol, lysolecithin as emulsifier, n-propanol as co-surfactant, cholesterol as oil phase. It was show that the microeroulsions are clear, transparent, stable system.