含pPpa的水通道蛋白AQPZ在无细胞体系中的表达及其水过滤特性  

Expression of p-Propargyloxyphenylalanine-Containing Aquaporin Z in Cell-Free System and its Application in Water Filtration

作　　者：庄冰佳 于道永[2] 黄磊[1] 徐志南[1] 蔡谨[1] 

机构地区：[1]浙江大学化学工程与生物工程学院,浙江杭州310027 [2]中国石油大学(华东)化学工程学院,山东青岛266580

出　　处：《高校化学工程学报》2016年第6期1335-1340,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(21276226;21306164)

摘　　要：水通道蛋白Z(AQPZ)具有水选择专一性强、渗透性高等特点,可广泛用于制备水回收和脱盐的生物仿生膜。定点突变詹氏甲烷球菌(Methanococcus jannaschii)的酪氨酸-t RNA合成酶(tyrosyl-t RNA synthetase,Tyr RS),使其可催化非天然氨基酸(丙炔氧基-L-苯丙氨酸(p-propargyloxyphenylalanine,p Ppa))合成对应氨酰t RNA。将上述转运系统与大肠杆菌无细胞体系结合,在AQPZ的特定位点引入了p Ppa将改性的AQPZ(P-AQPZ)重构到1,2-二油酰基磷脂酰胆碱(1,2-dioleoyl-sn-glycero-3-phosphocholine,DOPC),经停留光谱分析,其水渗透因子Pf值为3.42?10?4 m?s?1,是AQPZ的2.78倍。用截留反渗透装置分析发现P-AQPZ仿生膜的水通量高于AQPZ仿生膜并可保持较高的截盐率。Aquaporin Z （AQPZ） is a typical orthodox aquaporin with high water permeability and selectivity, and it could be widely used in biomimetic membrane for water recycling and desalination. Site-specific mutagenesis of tyrosyl-tRNAsynthetase （TyrRS） from Methanococcus jannaschii was processed to synthesize corresponding amino acyl tRNA from unnatural amino acids （p-propargyloxyphenylalanine,pPpa）. pPpa was then site-specifically incorporated into AQPZ by combining the above transfer system with a Escherichia coli cell-free system, and the modified AQPZ was reconstituted into 1,2-dioleoyl-sn-glycero-3-phosphocholine （DOPC） liposomes and analyzed by stopped-flow spectroscopy. The results show that the osmotic water permeability value （Pf） of the modified AQPZ proteoliposomes is 3.42×10^-4 m·s^-1, which is 2.78 times higher than that of the AQPZ proteoliposomes. The layer-by-layer membrane embedded with the modified AQPZ demonstrates higher water flux than the AQPZ embedded membrane with same high salt rejection rates.

关 键 词：非天然氨基酸 水通道蛋白Z 基因编码 生物仿生膜 无细胞体系 

分 类 号：Q786[生物学—分子生物学]