Chhetri D R, Adhikari J, Mukherjee A K
Plant Physiology and Biochemistry Laboratory, Post Graduate Department of Botany, Darjeeling Govt. College, Darjeeling, WB, India.
Prep Biochem Biotechnol. 2006;36(4):307-19. doi: 10.1080/10826060600912476.
Relative thermotolerance of the enzyme, L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4), from the chloroplastic and cytosolic sources of Diplopterygium glaucum was studied. The purification involved streptomycin sulphate precipitation, ammonium sulphate fractionation, ion-exchange chromatography, and molecular sieve chromatography. After the final chromatography, 16.62% of chloroplastic and 13.47% of cytosolic MIPS could be recovered. Between 15 degrees C and 55 degrees C, the two forms of MIPS exhibited differential thermal stability, which is related to the presence of the MIPS co-factor, NAD+. Added NAD+ increased the lower thermotolerance of the chloroplastic MIPS and the removal of 'built-in' NAD+ decreased the higher thermal stability of the cytosolic MIPS.
对来自光叶双盖蕨叶绿体和胞质来源的L-肌醇-1-磷酸合酶（MIPS；EC：5.5.1.4）的相对耐热性进行了研究。纯化过程包括硫酸链霉素沉淀、硫酸铵分级分离、离子交换色谱和分子筛色谱。最终色谱分离后，可回收16.62%的叶绿体MIPS和13.47%的胞质MIPS。在15℃至55℃之间，两种形式的MIPS表现出不同的热稳定性，这与MIPS辅因子NAD+的存在有关。添加NAD+提高了叶绿体MIPS的较低耐热性，去除“内在”的NAD+降低了胞质MIPS的较高热稳定性。
