Kefalides N A, Cameron J D, Tomichek E A, Yanoff M
J Biol Chem. 1976 Feb 10;251(3):730-3.
The synthesis of collagen has been demonstrated in endothelial cells of Descemet's membrane isolated from rabbit cornea. Incorporation of [14C]proline and [14C]lysine into nondialyzable protein was measured in the medium and cell fraction after incubating Descemet's membrane for up to 5 hours. In the [14C]collagen synthesized by the endothelium, 15% of the hydroxy[14C]proline was present as the 3-isomer. About 98% of the hydroxy[14C]lysine in the 14C-labeled-protein found in the medium was glycosylated; 95% of the glycosylated hydroxy[14C]lysine was in the form of the disaccharide glucosyl-galactosyl-hydroxy[14C]lysine. Time course experiments with [14C]proline indicated that there was a delay of about 60 min before significant amounts of [14C]collagen were secreted into the medium. The initial polypeptides of [14C]collagen synthesized by the corneal endothelium had an apparent molecular weight of 155,000. The chemical and physical properties of the [14C]collagen synthesized by rabbit corneal endothelium are consistent with those of basement membrane collagen synthesized by other cell types.
已证实在从兔角膜分离的Descemet膜的内皮细胞中可合成胶原蛋白。在将Descemet膜孵育长达5小时后，测定培养基和细胞组分中[14C]脯氨酸和[14C]赖氨酸掺入不可透析蛋白的情况。在内皮细胞合成的[14C]胶原蛋白中，15%的羟[14C]脯氨酸以3-异构体形式存在。培养基中14C标记蛋白中的羟[14C]赖氨酸约98%发生了糖基化；95%的糖基化羟[14C]赖氨酸为二糖葡萄糖基-半乳糖基-羟[14C]赖氨酸形式。用[14C]脯氨酸进行的时间进程实验表明，在大量[14C]胶原蛋白分泌到培养基中之前有大约60分钟的延迟。角膜内皮细胞合成的[14C]胶原蛋白的初始多肽的表观分子量为155,000。兔角膜内皮细胞合成的[14C]胶原蛋白的化学和物理性质与其他细胞类型合成的基底膜胶原蛋白的性质一致。
