Iynedjian P B, Möbius G, Seitz H J, Wollheim C B, Renold A E
Proc Natl Acad Sci U S A. 1986 Apr;83(7):1998-2001. doi: 10.1073/pnas.83.7.1998.
The tissue distribution of glucokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) was examined by protein blotting analysis. Antibodies raised against rat liver glucokinase recognized a single protein subunit with an apparent Mr of 56,500 on nitrocellulose blots of cytosol protein from liver, separated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. A protein of identical electrophoretic mobility was detected by immunoblotting of cytosol protein from pancreatic islets. Hepatic glucokinase and the immunoreactive islet product bound to and were eluted from DEAE-cellulose at the same ionic strength. Glucokinase was displayed as a set of two spots with apparent pI values of 5.54 and 5.64 by immunoblotting after two-dimensional gel electrophoresis. The two isoforms appeared equally abundant in liver extract, whereas the component with a pI of 5.64 was predominant in islets. By quantitative immunoblotting, glucokinase was estimated to represent 0.1% of total cytosol protein in liver and 1/20th as much in islets. The glucokinase activity of both liver and islet cytosols was suppressed by the antibodies to hepatic glucokinase. Immunoblotting of cytosol protein from intestinal mucosa, exocrine pancreas, epididymal adipose tissue, kidney, brain, and spleen failed to reveal the glucokinase protein. Thus, significant expression of the glucokinase gene appears restricted to the liver and pancreatic islets.
通过蛋白质印迹分析检测了葡萄糖激酶（ATP：D-己糖6-磷酸转移酶，EC 2.7.1.1）的组织分布。用针对大鼠肝脏葡萄糖激酶产生的抗体在十二烷基硫酸钠/聚丙烯酰胺凝胶电泳分离的肝脏胞质溶胶蛋白的硝酸纤维素印迹上识别出一个表观分子量为56,500的单一蛋白质亚基。通过对胰岛胞质溶胶蛋白进行免疫印迹检测到一种具有相同电泳迁移率的蛋白质。肝脏葡萄糖激酶和免疫反应性胰岛产物在相同离子强度下与DEAE-纤维素结合并从其上洗脱。二维凝胶电泳后通过免疫印迹显示葡萄糖激酶为一组两个斑点，表观pI值分别为5.54和5.64。这两种同工型在肝脏提取物中似乎同样丰富，而pI为5.64的组分在胰岛中占主导地位。通过定量免疫印迹法估计，葡萄糖激酶在肝脏中占总胞质溶胶蛋白的0.1%，在胰岛中的含量为肝脏的1/20。肝脏和胰岛胞质溶胶的葡萄糖激酶活性均被抗肝脏葡萄糖激酶的抗体所抑制。对肠黏膜、外分泌胰腺、附睾脂肪组织、肾脏、大脑和脾脏的胞质溶胶蛋白进行免疫印迹未能检测到葡萄糖激酶蛋白。因此，葡萄糖激酶基因的显著表达似乎仅限于肝脏和胰岛。
