Yamate T, Umekawa T, Iguchi M, Kurita T, Kohri K
Department of Urology, Kinki University School of Medicine.
Hinyokika Kiyo. 1997 Sep;43(9):623-7.
Osteopontin (OPN) has been identified as a matrix protein of calcium oxalate urinary stones by sequencing c-DNA for urinary stone protein. OPN, a phosphoprotein, is susceptible to thrombin digestion and specifically stainable with Stains-All. We examined the matrix in 4 kinds of urinary stones, calcium oxalate dihydrate, calcium phosphate, magnesium ammonium phosphate and uric acid; for the presence of OPN by staining thrombin-digestion and undigested matrix with Stains-All. Matrix was extracted with a 0.1 M ethylenediamine tetraacetic acid (EDTA) solution. Furthermore, the amino acid sequence was determined for the NH2-terminal 20 amino acid residues. OPN was identified in calcium oxalate dihydrate and calcium phosphate stones, but was absent in magnesium ammonium phosphate and uric acid stones. Our findings suggest that OPN, which binds tightly to hydroxyapatite and is related to bone formation as bone matrix, also participates in the formation of calcium-containing urinary stones.
通过对草酸钙尿结石蛋白的互补脱氧核糖核酸（c-DNA）进行测序，骨桥蛋白（OPN）已被确定为草酸钙尿结石的一种基质蛋白。OPN是一种磷蛋白，易受凝血酶消化作用的影响，且能用氨基黑10B特异性染色。我们通过用氨基黑10B对凝血酶消化后的和未消化的基质进行染色，来检测4种尿结石（二水草酸钙、磷酸钙、磷酸镁铵和尿酸）中的基质是否存在OPN。用0.1M乙二胺四乙酸（EDTA）溶液提取基质。此外，还测定了氨基末端20个氨基酸残基的氨基酸序列。在二水草酸钙结石和磷酸钙结石中鉴定出了OPN，但在磷酸镁铵结石和尿酸结石中未发现。我们的研究结果表明，OPN与羟基磷灰石紧密结合，作为骨基质与骨形成相关，它也参与含钙尿结石的形成。
