Structural basis for a non-phosphorus-containing cyclic peptide binding to Grb2-SH2 domain with high affinity
Structural basis for a non-phosphorus-containing cyclic peptide binding to Grb2-SH2 domain with high affinity
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DOI：
10.1016/s0006-291x(03)01291-9
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发表时间：
2003-08-08
影响因子：
3.1
通讯作者：
Roller, PP
中科院分区：
文献类型：
--
作者：
Li, P;Zhang, MC;Roller, PP
阻断含磷酸酪氨酸（pTyr）的活化受体与生长因子受体结合蛋白2（Grb 2）的Src同源2（SH 2）结构域之间的相互作用被认为是开发新的抗增殖剂的有效且无细胞毒性的策略，因为其可能关闭Ras活化途径。通常，pTyr-X-Asn最小结合基序是高亲和力配体结合Grb 2-SH 2结构域所需的。利用噬菌体展示技术，我们从10（7）个不同的序列中发现了一个具有中等结合亲和力的不含pTyr的环肽G1。为了理解这些新型非含磷抑制剂与Grb 2-SH 2结构域的高亲和力结合的结构基础，我们在本文中广泛研究了由于这些非磷酸化肽中不存在磷酸基团而导致的Tyr-2位置中酸性侧链的独特功能要求。还进行了全面的SAR研究，以开发基于这种新型模板的有效Grb 2-SH 2结构域拮抗剂。通过氨基酸侧链的肽模拟优化和分子模拟指导的骨架构象的约束，我们开发了几种具有低纳摩尔范围结合亲和力的有效拮抗剂，如IC 50 = 0.026 μ M的环肽20，这是迄今报道的最有效的非含磷Grb 2-SH 2拮抗剂之一。全细胞分析表明，肽20可以穿透细胞膜，并抑制在erbB 2过表达的MDA-MA-453癌细胞中的Grb 2与p185（erbB 2）的关联在低微摩尔浓度。爱思唯尔公司出版
Blocking the interaction between phosphotyrosine (pTyr) -containing activated receptors and the Src homology 2 (SH2) domain of the growth factor receptor bound protein 2 (Grb2) is considered to be an effective and non-cytotoxic strategy to develop new antiproliferative agents due to its potential to shut down the Ras activation pathway. Generally, the pTyr-X-Asn minimal binding motif is required for a high-affinity ligand binding to the Grb2-SH2 domain. Using phage-display techniques, we discovered a non-pTyr-containing cyclic peptide G1 with moderate binding affinity from 10(7) different sequences. To understand the structural basis for the high-affinity binding of these novel non-phosphorus-containing inhibitors to the Grb2-SH2 domain, we extensively studied herein the unique functional requirements of the acidic side chain in Tyr-2 position due to the absence of the phosphate group in these nonphosphorylated peptides. A comprehensive SAR study was also carried out to develop potent Grb2-SH2 domain antagonists based upon this novel template. With both the peptidomimetic optimization of the amino acid side-chains and the constraint of the backbone conformation guided by molecular modeling, we developed several potent antagonists with low nanomolar range binding affinity, such as cyclic peptide 20 with an IC50 = 0.026 muM, which is one of the most potent non-phosphorus-containing Grb2-SH2 antagonists reported to date. Whole cell assays indicate that peptide 20 can penetrate the cell membranes and inhibit the association of Grb2 with p185(erbB2) in erbB2-overexpressing MDA-MA-453 cancer cells at low micromolar concentrations. Published by Elsevier Inc.