人脑神经特异性烯醇化酶的纯化及其性质研究

Purification and Characterization of Neuron-specific Enolase From Human Brain

本研究设计了利用DEAE-52离子交换层析、Sephadex G-150凝胶过滤、以及经Ultrogel和DEAE-Sepharose CL-6B柱进一步层析分离获得高纯度人脑神经特异性烯醇化酶(NSE)的纯化方案。纯化的酶经SDS电泳鉴定为单一亚基区带,其亚基分子量约为45,000。NSE的等电点约为4.7。该酶作用2-磷酸甘油酸的km值为0.7mmol/L,对Mg^++的km值为0.7mmol/L。Mg^++为烯醇化酶必不可少的辅助因子。在50℃以下,NSE具有一定的热稳定性。

Neuron-specific enolase (NSE) has been purified from human brain. The method includes column chromatography on DEAE-52, Sephadex G-150, DEAE-Sep-hacel, Ultrogel and DEAE-Sepharose CL-6B. The specific activity of the purified NSE was 52.2 units/mg protein. The purified enzyme showed a single band on SDS -polyacrylamide gel electrophoresis, with a relative mobility corresponding to a sub-unit molecular weight of about 45000. The pI value for NSE is about 4.7 on PAGIF electrophoresis. The optimum pH for the enzyme is between 6.8-7.1, and Km values for Mg++ and 2-phosphoglycerate were found to be 0.1 and 0.7m mol/L, respectively. Mg++ was an essential colactor for the enolase.