Broze G J, Lange G W, Duffin K L, MacPhail L
Division of Hematology, Jewish Hospital, Washington University Medical Center, St Louis, MO 63110.
Blood Coagul Fibrinolysis. 1994 Aug;5(4):551-9.
Much of tissue factor pathway inhibitor (TFPI) in plasma is bound to lipoproteins. The major form of TFPI associated with low density lipoproteins (LDL) is 34 kDa, whereas that associated with high density lipoproteins (HDL) is 41 kDa and appears in part to represent a mixed disulphide complex between TFPI and apolipoprotein AII. The native and recombinant TFPI produced by mammalian cells in tissue culture and the TFPI released by heparin in vivo, however, are 34 kDa. Western blotting with antibodies raised against specific TFPI peptides and cation exchange chromatography under denaturing conditions of partially purified plasma TFPI suggest that only a fraction of TFPI circulating in plasma is in the form of the full length molecule, the remainder consisting of variably carboxyl-terminal truncated forms. Electrospray mass spectrometry of the isolated 34 kDa form of plasma TFPI, which predominantly circulates bound to LDL, confirms that it lacks a substantial portion of the carboxyl-terminus including at least a portion of the third Kunitz-type domain.
血浆中的组织因子途径抑制物（TFPI）大部分与脂蛋白结合。与低密度脂蛋白（LDL）相关的TFPI主要形式为34 kDa，而与高密度脂蛋白（HDL）相关的TFPI为41 kDa，并且部分似乎代表TFPI与载脂蛋白AII之间的混合二硫键复合物。然而，组织培养中哺乳动物细胞产生的天然和重组TFPI以及体内肝素释放的TFPI均为34 kDa。用针对特定TFPI肽产生的抗体进行蛋白质印迹分析以及在部分纯化的血浆TFPI变性条件下进行阳离子交换色谱分析表明，血浆中循环的TFPI只有一部分是全长分子形式，其余部分由羧基末端可变截短形式组成。对主要与LDL结合循环的分离的34 kDa血浆TFPI形式进行电喷雾质谱分析证实，它缺少羧基末端的很大一部分，包括至少一部分第三个Kunitz型结构域。
