Human complement component C3: cDNA coding sequence and derived primary structure.
Human complement component C3: cDNA coding sequence and derived primary structure.
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DOI：
10.1073/pnas.82.3.708
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发表时间：
1985-02
影响因子：
11.1
通讯作者：
M. D. Bruijn;Georg H. Fey
中科院分区：
文献类型：
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作者：
M. D. Bruijn;Georg H. Fey
给出了人补体成分C3的完整cDNA编码序列和衍生氨基酸序列。编码的前体分子包含22个氨基酸残基的信号肽、β链（645个残基）和α链（992个残基）。这两条链由四个精氨酸残基连接在一起，这些精氨酸残基不存在于成熟的蛋白质中。几个重要的功能位点已经定位，如硫酯位点、释放过敏毒素的切割位点、丝氨酸蛋白酶因子I切割的两个位点，以及具有白细胞动员活性的肽片段。已经确定了至少两个碳水化合物的附着位点，每条链上一个。人类C3与小鼠C3在核苷酸水平上具有79%的同源性，在氨基酸水平上具有77%的同源性。蛋白酶α - 2巨球蛋白和补体成分C4与C3具有相当的同源性，表明这三种蛋白是从一个共同的祖先进化而来的。
The complete cDNA coding sequence and derived amino acid sequence of human complement component C3 are presented. The encoded precursor molecule contains a signal peptide of 22 amino acid residues, the beta chain (645 residues), and the alpha chain (992 residues). The two chains are joined by four arginine residues not present in the mature protein. Several functionally important sites have been localized, such as the thiolester site, the cleavage site liberating the anaphylatoxin, and two sites of cleavage by the serine protease factor I, as well as a peptide fragment with leukocyte mobilizing activity. At least two carbohydrate attachment sites, one on each chain, have been identified. Human C3 has 79% identity to mouse C3 at the nucleotide level and 77% identity at the amino acid level. The protease alpha 2-macroglobulin and complement component C4 show considerable homology to C3, suggesting that the three proteins have evolved from a common ancestor.