聚乳酸-聚半胱氨酸混纺纤维毡用于谷胱甘肽S-转移酶的捕获和洗脱

本文研究一种分离纯化GST（谷胱甘肽S-转移酶）的方法：将嵌段聚合物聚左旋乳酸-聚半胱氨酸（PLLA—PCys）电纺丝制成超细纤维，将还原型谷胱甘肽（GSH）通过二硫键偶联到纤维上，再将纤维填充玻璃管，制成吸附柱；含有GST的混合溶液通过吸附柱时，GST被纤维捕获；再用含GSH的溶液流过吸附柱，GST被洗脱下来，经冷冻干燥获得GST纯品．用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳进行检测．结果表明，键合了GSH的PLLA—PCys混纺纤维毡能够从蛋白混合溶液中专一性地捕获GST，被捕获的GST可以有效地回收．所以，此种键合了GSH的电纺丝纤维可望用于GST或以GST为标签的蛋白的分离、纯化以及检测．

PLLA-PCys co-electrospun fibers for capture and elution of glutathione S-transferase

The copolymer poly（L-lactic acid）-b-poly（L-cysteine） （PLA-b-PCys） was co-electrospun with PLGA into ultrafine fibers. The reduced glutathione （GSH） was conjugated to fiber surfaces via disulfide bonds. The Glutathione S-transferase （GST） was captured onto GSH fibers based on the specific substrate-enzyme interaction btween the bound GSH and GST. The captured GST was eluted with free GSH aqueous solution and lyophilized to get pure GST powders. The results show that the GSH moieties on the fiber surface retain the bioactivity of the free GSH and thus they can bind specifically with GST and the GST in solution is captured onto the fiber surface. On the other hand, the bound GSH is not as active as free GSH so that the captured GST can be eluted off from the fiber by free GSH aqueous solution. Based on this principle, GST itself or its fused proteins can be separated and purified very easily. The preliminary purification efficacy is 6.5 mg·（g PCys）^-1. Further improvements are undertaken.