Coe F L, Nakagawa Y, Asplin J, Parks J H
Nephrology Section MC5100, University of Chicago, School of Medicine, IL 60637, USA.
Miner Electrolyte Metab. 1994;20(6):378-84.
Kidney cells produce at least three proteins that slow the rate of calcium oxalate crystallization. Nephrocalcin (NC), one of the three, is an acidic glycoprotein that contains gamma-carboxyglutamic acid (GLA), and inhibits nucleation, aggregation and growth of calcium oxalate crystals. Nephrocalcin is abnormal in urine of stone-forming patients, in lacking GLA. It acts by absorbing to crystal surfaces. NC is produced by cultured renal proximal tubule cells, and by some lines of renal carcinoma cells, but its regulation is not yet characterized. Its sequence is not known, nor do we known the molecular basis for the abnormal character of NC is stone-forming patients. Compared to Tamm-Horsefall protein and uropontin, the two other inhibitors, NC is very potent, and is probably of major importance in protecting kidneys against supersaturations caused by normal water conservation.
肾细胞至少产生三种可减缓草酸钙结晶速率的蛋白质。其中一种名为肾钙素（NC）的蛋白质是一种酸性糖蛋白，含有γ-羧基谷氨酸（GLA），可抑制草酸钙晶体的成核、聚集和生长。在形成结石患者的尿液中，肾钙素缺乏GLA，因而出现异常。它通过吸附于晶体表面发挥作用。肾钙素由培养的近端肾小管细胞以及某些肾癌细胞系产生，但其调控机制尚未明确。其序列未知，我们也不清楚在形成结石的患者中肾钙素异常特征的分子基础。与另外两种抑制剂Tamm-Horsefall蛋白和尿桥蛋白相比，肾钙素的作用非常强大，可能在保护肾脏免受正常节水导致的过饱和影响方面具有重要作用。
