Molecular cloning of S‐protein, a link between complement, coagulation and cell‐substrate adhesion.
Molecular cloning of S‐protein, a link between complement, coagulation and cell‐substrate adhesion.
复制标题
S-蛋白的分子克隆，补体、凝血和细胞基质粘附之间的联系。
作者：
D. Jenne;K. Stanley
已使用单克隆抗体分离编码人S蛋白的cDNA克隆，以筛选pEX中的cDNA文库。根据序列、组成和免疫学标准，这些克隆被证明是真实的S蛋白克隆。已确定S蛋白的完整开放阅读框序列，并显示其为459个氨基酸的单链多肽链，前有19个残基的裂解前导肽。未发现S蛋白多态性的证据，表明蛋白水解降解产生不同的分子量形式。在前44个氨基末端残基中，42个与所谓的生长调节素B肽相同，表明S蛋白是生长调节素B前体。序列的其余部分与血清扩散因子玻连蛋白具有惊人的同源性，也已显示其氨基末端含有生长调节蛋白B序列。我们得出结论，S蛋白和玻连蛋白是相同的，并讨论了这一发现与凝血和补体途径的相关性。
cDNA clones coding for human S‐protein have been isolated using monoclonal antibodies to screen a cDNA library in pEX. These clones are shown to be authentic S‐protein clones on the basis of sequence, composition and immunological criteria. The complete open reading frame sequence for S‐protein has been determined and shows it to be a single polypeptide chain of 459 amino acids preceded by a cleaved leader peptide of 19 residues. No evidence was found for polymorphism of S‐protein suggesting that different molecular weight forms arise by proteolytic degradation. Of the first 44 amino‐terminal residues 42 are identical with the so‐called somatomedin B peptide suggesting that S‐protein is the somatomedin B precursor. Striking homology is found in the rest of the sequence with the serum spreading factor, vitronectin, which has also been shown to contain somatomedin B sequences at its amino terminus. We conclude that S‐protein and vitronectin are identical and discuss the relevance of this finding to the coagulation and complement pathways.