Platelet-derived growth factor binds specifically to receptors on vascular smooth muscle cells and the binding becomes nondissociable.
Platelet-derived growth factor binds specifically to receptors on vascular smooth muscle cells and the binding becomes nondissociable.
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血小板衍生的生长因子与血管平滑肌细胞上的受体特异性结合，并且这种结合变得不可解离。
DOI：
10.1073/pnas.79.19.5867
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发表时间：
1982
影响因子：
11.1
通讯作者：
Antoniades,HN
中科院分区：
文献类型：
--
作者：
Williams,LT;Tremble,P;Antoniades,HN
放射性碘化血小板衍生生长因子（125I-PDGF）用于血管平滑肌细胞PDGF结合位点的研究。125I-PDGF刺激细胞增殖的能力与与培养的血管平滑肌细胞特异性结合的能力之间存在良好的相关性。两种工艺的半最大浓度均为0.1 nM。每个细胞有5万个结合位点。用20 mM二硫苏糖醇处理PDGF制备的还原PDGF，既不能与平滑肌细胞结合，也不能刺激细胞增殖。在10 nM浓度下，表皮生长因子、神经生长因子、成纤维细胞生长因子和组蛋白B不竞争结合位点。125I-PDGF结合在4℃时缓慢可逆，在37℃孵育1 min后迅速完全可逆。在37℃继续孵育后，结合变得不可逆。在37℃下，125I-PDGF结合的非解离状态形成的半衰期约为5 min，在4℃下，即使孵育1小时也未形成非解离状态。这些数据表明，我们标记的位点是介导PDGF有丝分裂作用的PDGF受体，PDGF结合的不可解离状态在37℃时形成。不可解离的PDGF很可能代表内化配体或与配体结合后转化为高亲和力状态的位点结合。
Radioiodinated platelet-derived growth factor (125I-PDGF) was used in studies of PDGF binding sites on vascular smooth muscle cells. There was an excellent correlation between the ability of 125I-PDGF to stimulate cell proliferation and to bind specifically to cultured vascular smooth muscle cells. The half-maximal concentration for both processes was 0.1 nM. There were 50,000 binding sites per cell. Reduced PDGF, prepared by treatment of PDGF with 20 mM dithiothreitol, had neither the ability to bind to smooth muscle cells nor to stimulate cellular proliferation. Epidermal growth factor, nerve growth factor, fibroblast growth factor, and histone B did not compete for the binding sites at a concentration of 10 nM. 125I-PDGF binding was slowly reversible at 4 degrees C and was rapidly and totally reversible after a 1-min incubation at 37 degrees C. After continued incubation at 37 degrees C, the binding became irreversible. The half-time for formation of the nondissociable state of 125I-PDGF binding was approximately equal to 5 min at 37 degrees C. The nondissociable state of binding was not formed at 4 degrees C even after 1 hr of incubation. These data suggest that the sites we labeled are the PDGF receptors that mediate PDGF's mitogenic action and that a nondissociable state of PDGF binding is formed at 37 degrees C. It is likely that nondissociable PDGF represents internalized ligand or binding to sites that are converted to a high-affinity state after the ligand binds.