The immplication of crystal surface binding substances (CSBS) on urinary stone formation.

尿大分子被认为在结石的形成中起着重要作用。本研究的目的是研究尿蛋白对结石形成的影响。1.在人体全尿中加入钙和草酸，得到晶体表面结合物质(CSBS)。CSBS是吸附在草酸钙晶体表面的尿液大分子，对草酸钙结晶有很强的抑制作用。通过DEAE-SepharoseCL-6B离子层析分离得到富含抑制草酸钙晶体生长活性的蛋白质组分。这些组分经羟基磷灰石柱层析，磷酸钠分级洗脱。3.SDS-PAGE显示多条蛋白质条带。用氨基酸测序仪分析了相对分子质量为30Kd和67Kd的两种主要蛋白质。结果表明，30Kd蛋白与人凝血酶原蛋白同源性较高，67Kd蛋白与人骨桥蛋白同源性较高。4.免疫印迹分析了羟基磷灰石柱层析物的蛋白质组成。检测人血清白蛋白、α1-酸性糖蛋白、α1-微球蛋白、α2-HS糖蛋白、视黄醇结合蛋白、转铁蛋白、Tamm-Horsfall粘蛋白和凝血酶原。然而，我们认为这些蛋白质对草酸钙晶体的形成没有明显的作用，因为每个蛋白质组分对晶体生长的抑制作用都很弱。我们得出结论，CSBS中包含的其他未知蛋白质被认为是主要的蛋白质抑制剂。

Urinary macromolecules are considered to play a important role in stone formation. The aim of our study is to characterize the urinary protein affecting stone formation.1.We obtained crystal surface binding substance (CSBS) by adding calcium and oxalate to human whole urine. The CSBS is urinary macromolecules absorbed onto the surface of calcium oxalate crystals and yields strong inhibitory activity on calcium oxalate crystallization. Proteins contained in the CSBS are analyzed.2.Fractions enriched in proteins with strong calcium oxalate crystal growth inhibitory activity are obtained by DEAE-Sepharose CL-6B ion-chromatography. These fractions are fractionated by hydroxyapatite column with stepwise elution of sodium phosphate.3.The SDS-PAGE shows many bands of protein. Two major proteins, molecular weight of 30Kd and 67Kd, are analyzed by a amino acid sequencer. As a result, 30Kd protein is identified with human prothrombin and 67Kd protein with human osteopontin.4.Protein composition of fractions obtained by hydroxyapatite column is also analyzed by immunoblotting. Human serum albumin, alpha 1-acid glycoprotein, alpha 1-microglobulin, alpha 2-HS glycoprotein, retinol-binding protein, transferrin, Tamm-Horsfall mucoprotein and prothrombin are detected. However, it is considered that these proteins does not play a signifficant role on calcium oxalate crystal formation because each fractions containing each proteins reveal weak inhibitory power on crystal growth.We conclude that other unknown proteins included in CSBS are thought to be dominant protein inhibitors.