VEGF165-binding sites within heparan sulfate encompass two highly sulfated domains and can be liberated by K5 lyase
VEGF165-binding sites within heparan sulfate encompass two highly sulfated domains and can be liberated by K5 lyase
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DOI：
10.1074/jbc.m510760200
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发表时间：
2006-01-20
影响因子：
4.8
通讯作者：
Stringer, SE
中科院分区：
文献类型：
--
作者：
Robinson, CJ;Mulloy, B;Stringer, SE
血管内皮生长因子（VEGF）家族的蛋白质控制血管的形成和生长。最有效和广泛表达的同种异构体VEGF（165）以二硫连接的同型二聚体的形式分泌，具有两个相同的肝素结合位点。与硫酸肝素（HS）的相互作用调节VEGF对其信号受体的扩散、半衰期和亲和力（165）。我们已经确定了介导VEGF（165）二聚体特异性结合的一些关键HS结构特征。羧酸基团和HS的2-O-、6-O-和n -磺化有助于VEGF（165）相互作用的强度；然而，6- o -硫酸盐似乎特别重要。肝素酶、肝素酶或肝素酶切割HS严重降低VEGF（165）的结合。相比之下，K5裂解酶切割的HS保留了显著的VEGF（165）亲和力，这表明生长因子的结合位点存在于硫酸化的延伸区域内。结合研究和分子模型表明，长度为6或7个残基的寡糖足以完全占据VEGF（165）单体的肝素结合位点。所提供的数据与一个模型一致，即VEGF（165）二聚体的两个肝素结合位点同时与HS链的高度硫酸化s结构域区域相互作用，该区域可以通过一段过渡序列连接。
The vascular endothelial growth factor (VEGF) family of proteins controls the formation and growth of blood vessels. The most potent and widely expressed isoform, VEGF(165), is secreted as a disulfide-linked homodimer with two identical heparin-binding sites. Interactions with heparan sulfate (HS) regulate the diffusion, half-life, and affinity of VEGF(165) for its signaling receptors. We have determined a number of key HS structural features that mediate the specific binding of the VEGF(165) dimer. Carboxylate groups and 2-O-, 6-O-, and N-sulfation of HS contributed to the strength of the VEGF(165) interaction; however, 6-O-sulfates appeared to be particularly important. Cleavage of HS by heparinase, heparitinase, or heparanase severely reduced VEGF(165) binding. In contrast, K5 lyase-cleaved HS retained significant VEGF(165) affinity, suggesting that binding sites for the growth factor are present within extended stretches of sulfation. Binding studies and molecular modeling demonstrated that an oligosaccharide 6 or 7 residues long was sufficient to fully occupy the heparin-binding site of a VEGF(165) monomer. The data presented are consistent with a model whereby the two heparin-binding sites of the VEGF(165) dimer interact simultaneously with highly sulfated S-domain regions of the HS chain that can be linked through a stretch of transition sequence.