Highly multilayered urease decomposes highly concentrated urea
Highly multilayered urease decomposes highly concentrated urea
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DOI：
10.1021/bp020072p
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发表时间：
2003-03-01
影响因子：
2.9
通讯作者：
Lee, W
中科院分区：
文献类型：
--
作者：
Kobayashi, S;Yonezu, SJ;Lee, W
通过将尿素酶与接枝到多孔中空纤维膜的孔表面上的阴离子交换聚合物链进行离子交换结合，并随后将尿素酶与转氨酶交联，以每克基质1.2 g尿素酶的密度固定尿素酶。在尿素溶液（其浓度范围为2至8 M）渗透通过厚度约为1 mm的所得膜的孔期间，尿素被水解。在低于1 mL/h的渗透速率下实现4 M尿素的定量水解，即，在环境温度下，停留时间大于5.1分钟。这种性能归因于尿素通过高密度固定化尿素酶聚合物链边缘的孔隙的对流运输。尿素酶变性的尿素浓度高于6 M的存在下，同时水解尿素。
Urease was immobilized at a density of 1.2 g of urease per gram of a matrix via ion-exchange binding of urease to an anion-exchange polymer chain grafted onto a pore surface of a porous hollow-fiber membrane and subsequent cross-linking of urease with transglutaminase. Urea was hydrolyzed during the permeation of a urea solution, the concentration of which ranged from 2 to 8 M, through the pores of the resultant membrane with a thickness of approximately 1 mm. Quantitative hydrolysis of 4 M urea was achieved at a permeation rate lower than 1 mL/h, i.e., a residence time longer than 5.1 min, at ambient temperature. This performance is ascribed to convective transport of urea through the pores rimmed by the urease-immobilized polymer chains at a high density. Urease was denatured in the presence of urea at concentrations higher than 6 M while hydrolyzing urea.