Yang F, Brune J L, Naylor S L, Cupples R L, Naberhaus K H, Bowman B H
Proc Natl Acad Sci U S A. 1985 Dec;82(23):7994-8. doi: 10.1073/pnas.82.23.7994.
The group-specific component (Gc) is the major vitamin D-binding protein in plasma. The gene encoding Gc is linked, on human chromosome 4, to the albumin and alpha-fetoprotein genes. These two genes previously were shown to have evolved from a smaller ancestral gene by intragenic triplication. Recombinant plasmids containing human cDNA encoding Gc have been isolated by screening an adult human liver library with a mixed oligonucleotide probe. Characterization of Gc cDNA has provided the complete amino acid sequence of the protein and revealed strong sequence homology with albumin and alpha-fetoprotein. Of particular interest is a conserved pattern of disulfide bridges that form the triple-domain structures in albumin, alpha-fetoprotein, and Gc. Gc cDNA was used as a probe in Southern blot analysis of somatic-cell hybrids to confirm that the Gc locus is on chromosome 4.
群体特异性成分（Gc）是血浆中主要的维生素D结合蛋白。编码Gc的基因在人类4号染色体上与白蛋白基因和甲胎蛋白基因相连。先前已表明这两个基因是通过基因内重复从一个较小的祖先基因进化而来的。通过用混合寡核苷酸探针筛选成人肝脏文库，已分离出含有人Gc cDNA的重组质粒。对Gc cDNA的特性分析已得出该蛋白完整的氨基酸序列，并揭示了其与白蛋白和甲胎蛋白的强序列同源性。特别令人感兴趣的是在白蛋白、甲胎蛋白和Gc中形成三结构域结构的二硫键桥的保守模式。Gc cDNA被用作探针进行体细胞杂种的Southern印迹分析，以确认Gc基因座位于4号染色体上。
