High-affinity binding of basic fibroblast growth factor and platelet-derived growth factor-AA to the core protein of the NG2 proteoglycan
High-affinity binding of basic fibroblast growth factor and platelet-derived growth factor-AA to the core protein of the NG2 proteoglycan
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DOI：
10.1074/jbc.274.24.16831
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发表时间：
1999-06-11
影响因子：
4.8
通讯作者：
Stallcup, WB
中科院分区：
文献类型：
--
作者：
Goretzki, L;Burg, MA;Stallcup, WB
NG2是一种跨膜的硫酸软骨素蛋白多糖，由几个发育谱系的未成熟祖细胞和某些类型的恶性细胞表达。体外研究表明，NG2参与了血小板衍生生长因子-α受体的生长因子激活。本研究采用两种不同的检测系统：酶联免疫吸附测定法和光学生物传感器(Biacore)系统，研究了重组NG2核心蛋白与多种不同生长因子(表皮生长因子、碱性成纤维细胞生长因子、血小板衍生生长因子AA、PDGF-BB、血管内皮生长因子165和转化生长因子β1)相互作用的能力。两种方法均可证实bFGF和PDGF-AA与NG2核心蛋白的高亲和力结合。使用Biacore软件分析程序和固相结合数据的非线性回归分析，获得了这些生长因子与NG2结合的低纳摩尔范围内的K-D值。结果进一步表明，NG2至少含有这两种生长因子的两个结合位点。在这两种检测中，PDGF-BB、转化生长因子-β1、血管内皮生长因子和EGF与NG2的结合很少或没有。这些数据表明，NG2可以在细胞表面组织和呈递某些类型的有丝分裂生长因子方面发挥重要作用。
NG2 is a transmembrane chondroitin sulfate proteoglycan that is expressed by immature progenitor cells in several developmental lineages and by some types of malignant cells. In vitro studies have suggested that NG2 participates in growth factor activation of the platelet-derived growth factor-alpha receptor. In this study the ability of recombinant NG2 core protein to interact with several different growth factors (epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-AA, PDGF-BB, vascular endothelial growth factor (VEGF)(165) and transforming growth factor (TGF)-beta 1) was investigated using two different assay systems: enzyme-linked immunosorbent assay-type solid-phase binding and an optical biosensor (BIAcore) system. High-affinity binding of bFGF and PDGF-AA to the core protein of NG2 could be demonstrated with both types of assays. Using both the BIAcore software analysis program and nonlinear regression analysis of the solid phase binding data, K-D values in the low nanomolar range were obtained for binding of each of these growth factors to NG2. The results further indicate that NG2 contains at least two binding sites for each of these two growth factors. PDGF-BB, TGF-beta 1, VEGF, and EGF exhibited little or no binding to NG2 in either type of assay. These data suggest that NG2 can have an important role in organizing and presenting some types of mitogenic growth factors at the cell surface.