Hayward C P, Kelton J G
McMaster University Medical Centre, Hamilton, Ontario, Canada.
Curr Opin Hematol. 1995 Sep;2(5):339-44. doi: 10.1097/00062752-199502050-00003.
Multimerin is a massive, disulfide-linked protein with a unique complementary DNA sequence. It is stored in platelets and the endothelium of blood vessels and is comprised of subunits linked by interchain disulfide bonds to form large, variably sized homomultimers. The multimerin subunits are derived from a common precursor protein, promultimerin, which undergoes proteolysis and extensive N-glycosylation during biosynthesis. The complementary DNA sequence of multimerin indicates that multimerin is a novel protein, with Arg-Gly-Asp-Ser, coiled-coil, and epidermal growth factor-like domains. The C-terminal region of multimerin resembles the globular head domain of complement C1q and collagens type VIII and X. Multimerin is expressed by megakaryocytes and endothelial cells and stored within platelet alpha granules and endothelial cell Weibel-Palade bodies. Following cellular activation, multimerin is released and binds to these cells and the extracellular matrix. The function of this novel protein in hemostasis is under investigation. Recent studies have identified multimerin as a specific Factor V/Va binding protein that is complexed with Factor V within platelet alpha granules.
多聚体蛋白是一种巨大的、通过二硫键连接的蛋白质，具有独特的互补DNA序列。它储存于血小板和血管内皮中，由通过链间二硫键连接的亚基组成，形成大小可变的大型同型多聚体。多聚体蛋白亚基来源于一种共同的前体蛋白——前多聚体蛋白，该前体蛋白在生物合成过程中经历蛋白水解和广泛的N-糖基化。多聚体蛋白的互补DNA序列表明它是一种新型蛋白质，具有精氨酸-甘氨酸-天冬氨酸-丝氨酸、卷曲螺旋和表皮生长因子样结构域。多聚体蛋白的C末端区域类似于补体C1q以及Ⅷ型和Ⅹ型胶原的球状头部结构域。多聚体蛋白由巨核细胞和内皮细胞表达，并储存于血小板α颗粒和内皮细胞的魏尔-帕拉德小体中。细胞激活后，多聚体蛋白被释放并与这些细胞和细胞外基质结合。这种新型蛋白质在止血中的功能正在研究中。最近的研究已确定多聚体蛋白是一种特异性的因子V/Va结合蛋白，它在血小板α颗粒内与因子V形成复合物。
