Collins H W, Buettger C, Matschinsky F
Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia 19104.
Proc Natl Acad Sci U S A. 1990 Jul;87(14):5494-8. doi: 10.1073/pnas.87.14.5494.
High-resolution two-dimensional PAGE was used to search for glucose-response proteins in isolated pancreatic islets that were labeled with [35S]methionine at ambient glucose concentrations of 0-18 mM. A 65-kDa protein, isoelectric focusing point of approximately 6.6-7.0, was discovered that showed at least a 20-fold stimulation of radiolabeling when glucose in the labeling medium was increased from 3 to 18 mM, in contrast to a 2.5-fold enhancement of label incorporation into total islet proteins. This 65-kDa protein is evident after 30 min of labeling with 18 mM glucose and is preferentially synthesized compared to its nearest neighbors after both 30 and 60 min of labeling. Glucose induction of the 65-kDa protein was virtually blocked by D-mannoheptulose. Glucose induction of this 65-kDa protein is in practically all aspects comparable to glucose induction of insulin and glucokinase in pancreatic beta cells. A working hypothesis is developed proposing that glucose-response proteins or "glucospondins" are pivotal constituents of pancreatic islet cells and that their discovery and exploration promise new insights into normal and pathological islet cell function.
高分辨率二维聚丙烯酰胺凝胶电泳用于在分离的胰岛中寻找葡萄糖反应蛋白，这些胰岛在0 - 18 mM的环境葡萄糖浓度下用[35S]甲硫氨酸进行标记。发现一种65 kDa的蛋白质，其等电聚焦点约为6.6 - 7.0，当标记培养基中的葡萄糖从3 mM增加到18 mM时，其放射性标记至少有20倍的刺激，相比之下，标记掺入总胰岛蛋白的增强为2.5倍。在用18 mM葡萄糖标记30分钟后，这种65 kDa的蛋白质很明显，并且在标记30分钟和60分钟后，与其最接近的相邻蛋白相比，它被优先合成。65 kDa蛋白质的葡萄糖诱导几乎被D - 甘露庚酮糖阻断。这种65 kDa蛋白质的葡萄糖诱导在几乎所有方面都与胰腺β细胞中胰岛素和葡萄糖激酶的葡萄糖诱导相当。提出了一个工作假设，即葡萄糖反应蛋白或“葡萄糖应答素”是胰岛细胞的关键成分，对它们的发现和探索有望为正常和病理胰岛细胞功能带来新的见解。
