Middleditch C, Clottes E, Burchell A
Department of Obstetrics and Gynaecology, Ninewells Hospital and Medical School, Dundee University, UK.
FEBS Lett. 1998 Aug 14;433(1-2):33-6. doi: 10.1016/s0014-5793(98)00878-3.
There are differences in the kinetic properties of the liver and brain microsomal glucose-6-phosphate transport systems suggesting the possibility of tissue specific isoforms. The availability of a human liver cDNA sequence which is mutated in patients with deficiencies of liver microsomal glucose-6-phosphate transport (glycogen storage disease 1b) made it possible to determine if a brain isoform exists. Northern blots of liver and brain RNA revealed that the mRNA of the brain form is slightly longer than the liver one. Isolation and sequencing of the respective human brain cDNA revealed that the brain protein has an additional 22 amino acid sequence.
肝脏和脑微粒体葡萄糖-6-磷酸转运系统的动力学特性存在差异，这表明可能存在组织特异性同工型。人类肝脏cDNA序列的获得使得确定脑同工型是否存在成为可能，该序列在肝脏微粒体葡萄糖-6-磷酸转运缺陷患者（糖原贮积病1b型）中发生了突变。肝脏和脑RNA的Northern印迹显示，脑型mRNA略长于肝型。对相应人类脑cDNA的分离和测序表明，脑蛋白具有一个额外的22个氨基酸序列。
