Homocysteine binds to human plasma fibronectin and inhibits its interaction with fibrin
Homocysteine binds to human plasma fibronectin and inhibits its interaction with fibrin
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DOI：
10.1161/01.atv.0000023899.93940.7c
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发表时间：
2002-08-01
影响因子：
8.7
通讯作者：
Jacobsen, DW
中科院分区：
文献类型：
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作者：
Majors, AK;Sengupta, S;Jacobsen, DW
目的-超过 70% 的循环同型半胱氨酸通过二硫键与蛋白质结合，但对结合同型半胱氨酸的特定蛋白质及其由于同型半胱氨酸结合而产生的功能知之甚少。方法和结果-当人血浆与 [S-35]L-同型半胱氨酸一起孵育时，大部分同型半胱氨酸与白蛋白结合。然而，检测到了额外的同型半胱氨酸结合蛋白，其中 1 个与纤连蛋白共迁移。用 2-巯基乙醇处理去除了结合的同型半胱氨酸，证明了二硫键的参与。相反，[S-35]L-半胱氨酸不与纤连蛋白结合。纯化的纤连蛋白每个纤连蛋白二聚体结合大约 5 个同型半胱氨酸分子。高半胱氨酸化纤连蛋白的有限胰蛋白酶消化的 SDS-PAGE 显示，几个胰蛋白酶片段含有 [S-35] 高半胱氨酸。序列分析表明，含有结合同型半胱氨酸的片段主要定位于纤维蛋白结合域内和邻近的C端区域。纤连蛋白的同型半胱氨酸化显着抑制其结合纤维蛋白的能力达 62%（P
Objective-More than 70% of circulating homocysteine is disulfide-bonded to protein, but little is known about the specific proteins that bind homocysteine and their function as a consequence of homocysteine binding.Methods and Results-When human plasma was incubated with [S-35]L-homocysteine, most of the homocysteine bound to albumin. However, additional homocysteine-binding proteins were detected, and 1 of them comigrated with fibronectin. Treatment with 2-mercaptoethanol removed the bound homocysteine, demonstrating the involvement of disulfide bonding. In contrast, [S-35]L-cysteine did not bind to fibronectin. Purified fibronectin bound approximate to5 homocysteine molecules per fibronectin dimer. SDS-PAGE of a limited trypsin digestion of homocysteinylated fibronectin showed that several tryptic fragments contained [S-35]homocysteine. Sequence analysis demonstrated that the fragments containing bound homocysteine had localized mainly to the C-terminal region, within and adjacent to the fibrin-binding domain. Homocysteinylation of fibronectin significantly inhibited its capacity to bind fibrin by 62% (P