Murphy B F, Kirszbaum L, Walker I D, d'Apice A J
Department of Nephrology, Royal Melbourne Hospital, Australia.
J Clin Invest. 1988 Jun;81(6):1858-64. doi: 10.1172/JCI113531.
We report herein the isolation and initial characterization of a novel protein, termed SP-40,40, which is present at moderate levels (35-105 micrograms/ml) in normal human serum. SP-40,40 is deposited in the renal glomeruli of patients with glomerulonephritis but is not found in normal glomeruli. The protein is a heterodimeric structure of relative molecular mass 80 kD, both chains of which are of a similar size (40 kD). The amino-terminal sequences of both chains are unrelated to one another and possess no significant homology to any known protein sequence. The tissue distribution of SP-40,40 closely resembles that of the terminal complement components and its physicochemical properties are similar to, but distinct from, those of the S protein of complement. We have identified SP-40,40 in the SC5b-9 complex of complement and have demonstrated incorporation of labeled SP-40,40 into this complex. These data suggest that SP-40,40 is an additional component of SC5b-9.
我们在此报告一种名为SP-40,40的新型蛋白质的分离及初步特性研究。该蛋白在正常人血清中含量适中（35 - 105微克/毫升）。SP-40,40沉积于肾小球肾炎患者的肾小球中，而在正常肾小球中未发现。该蛋白是一种相对分子质量为80 kD的异二聚体结构，两条链大小相似（40 kD）。两条链的氨基末端序列彼此无关，与任何已知蛋白质序列均无显著同源性。SP-40,40的组织分布与补体末端成分极为相似，其物理化学性质与补体S蛋白相似但又不同。我们已在补体的SC5b-9复合物中鉴定出SP-40,40，并证明标记的SP-40,40可掺入该复合物。这些数据表明SP-40,40是SC5b-9的另一个成分。
