Lundwall A, Dackowski W, Cohen E, Shaffer M, Mahr A, Dahlbäck B, Stenflo J, Wydro R
Proc Natl Acad Sci U S A. 1986 Sep;83(18):6716-20. doi: 10.1073/pnas.83.18.6716.
Protein S is a cofactor of activated protein C; together they function as a regulator of blood coagulation. A human liver cDNA library constructed in bacteriophage lambda gt11 was screened with DNA fragments from a full-length bovine cDNA clone encoding protein S. Several cDNA clones were isolated and sequenced. The combined cDNA sequences encoded the mature protein and 15 residues of the leader sequence when compared to bovine protein S. Human protein S is a single-chain protein consisting of 635 amino acids with 82% homology to bovine protein S. After an NH2-terminal gamma-carboxyglutamic acid-containing region, there is a short region with thrombin-sensitive bond(s), followed by a region with four repeat sequences that are homologous to the precursor of mouse epidermal growth factor. In contrast to the other vitamin K-dependent plasma proteins, the COOH-terminal portion of human protein S does not show any resemblance to serine proteases.
蛋白S是活化蛋白C的辅因子；它们共同作为血液凝固的调节剂发挥作用。用编码蛋白S的全长牛cDNA克隆的DNA片段筛选在噬菌体λgt11中构建的人肝cDNA文库。分离并测序了几个cDNA克隆。与牛蛋白S相比，组合的cDNA序列编码成熟蛋白和前导序列的15个残基。人蛋白S是一种单链蛋白，由635个氨基酸组成，与牛蛋白S有82%的同源性。在含NH2末端γ-羧基谷氨酸的区域之后，有一个具有凝血酶敏感键的短区域，接着是一个与小鼠表皮生长因子前体同源的具有四个重复序列的区域。与其他维生素K依赖性血浆蛋白不同，人蛋白S的COOH末端部分与丝氨酸蛋白酶没有任何相似之处。
