以聚醚多元醇和甲苯二异氰酸酯(TDI)为原料,选用氨基酰化酶I作为模型酶,采用一步发泡法,将酶固定在软质聚氨酯泡沫塑料(FPUF)上,并对其进行表征.研究结果表明,在发泡过程中加入一定量的惰性蛋白质,对酶蛋白有一定的屏蔽效果,降低了被TDI损伤的概率,客观上对酶分子起到保护作用,使固定化后的酶活力收率有所提高.测得FPUF对蛋白质的负载率高达100%,固定化酶活力收率为81.03%,该固定化酶的最适pH值为6.8,与最适pH值为7的酶液相比,略向酸性偏移;最适反应温度与游离酶相似,在50～70℃.将固定化酶用于拆分乙酰-DL-甲硫氨酸的试验,体现了较好的连续使用稳定性,其半衰期为404.3 min.
Lipase and lauric acid were added into a copolymer system, which contained PEG400-dimethacrylate, trimethylolpropane trimethacrylate, and a surface-active agent.The polymerization was initiated by ultraviolet irradiation .Then recorded lipase polymers (RLP) of locking lipase conformation were obtained after lauric acid was extracted by a neat organic solvent.The adsorption of RLP in the lauric acid solution was studied.The adsorption isothermal curves were measured at temperature 30—50℃.The results indicated that RLP’s adsorption capacity was far stronger than blank carrier’s and immobilized lipase polymers (ILP)’s,about 8.7 and 3.9 times respectively.The adsorption process followed the Langmuir and Freundlich isothermal adsorption equations.
