Plasma binding proteins for platelet-derived growth factor that inhibit its binding to cell-surface receptors.
Plasma binding proteins for platelet-derived growth factor that inhibit its binding to cell-surface receptors.
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血小板衍生生长因子的血浆结合蛋白，抑制其与细胞表面受体的结合。
DOI：
10.1073/pnas.81.11.3424
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发表时间：
1984
影响因子：
11.1
通讯作者：
Ross,R
中科院分区：
文献类型：
--
作者：
Raines,EW;Bowen-Pope,DF;Ross,R
有证据表明，血小板衍生生长因子 (PDGF) 与血浆成分的结合会抑制 PDGF 与其细胞表面丝裂原受体的结合。在许多不同物种的血浆中发现了大约等量的 PDGF 结合活性，通过放射受体测定已知这些物种的凝血中含有 PDGF 同系物。凝血级联的激活并没有显着改变血浆成分的PDGF结合活性。通过凝胶过滤定义抑制PDGF与其细胞表面受体结合的血浆组分的三个分子量类别：约等于40,000、150,000和大于500,000。 125I 标记的 PDGF 与最高分子量血浆组分的特异性结合也可以通过凝胶过滤来证明。 PDGF 与这些血浆成分的结合在低 pH 条件下或使用盐酸胍时是可逆的，并且可以从较高分子量的组分中回收活性 PDGF。免疫学和功能证据表明最高分子量的血浆部分可能是α2-巨球蛋白。提出了一种模型，其中体内释放的PDGF的活性可以通过与这些血浆结合成分的关联以及通过与细胞表面PDGF受体的高亲和力结合来调节。
Evidence is presented that the binding of platelet-derived growth factor (PDGF) to plasma constituents inhibits the binding of PDGF to its cell-surface mitogen receptor. Approximately equivalent amounts of PDGF-binding activity were found in plasma from a number of different species known by radioreceptor assay to contain PDGF homologues in their clotted blood. Activation of the coagulation cascade did not significantly alter the PDGF-binding activity of the plasma components. Three molecular weight classes of plasma fractions that inhibit PDGF binding to its cell-surface receptor were defined by gel filtration: approximately equal to 40,000, 150,000, and greater than 500,000. Specific binding of 125I-labeled PDGF to the highest molecular weight plasma fraction could also be demonstrated by gel filtration. The binding of PDGF to these plasma components was reversible under conditions of low pH or with guanidine X HCl, and active PDGF could be recovered from the higher molecular weight fractions. Immunologic and functional evidence is presented that the highest molecular weight plasma fraction may be alpha 2-macroglobulin. A model is proposed in which the activity of PDGF released in vivo may be regulated by association with these plasma binding components and by high-affinity binding to cell-surface PDGF receptors.