Structural mimicry of retroviral Tat proteins by constrained, β-hairpin peptidomimetics:: Ligands with high affinity and selectivity for viral TAR RNA regulatory elements
Structural mimicry of retroviral Tat proteins by constrained, β-hairpin peptidomimetics:: Ligands with high affinity and selectivity for viral TAR RNA regulatory elements
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DOI：
10.1021/ja0497680
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发表时间：
2004-06-09
影响因子：
15
通讯作者：
Robinson, JA
中科院分区：
文献类型：
--
作者：
Athanassiou, Z;Dias, RLA;Robinson, JA
描述了一种设计牛免疫缺陷病毒（BIV） Tat蛋白的β -发夹肽拟配体的方法，该配体抑制其与反激活反应元件（TAR） RNA的结合。通过将与Tat RNA识别元件相关的发夹诱导D-Pro-L-Pro模板序列接枝，获得了一个肽模拟物库。鉴定出一种发夹模拟物与BIV TAR紧密结合（K-d约为150 nM），另一种也与HIV-1 TAR RNA结合（K-d约为1-2 nM）。（在同一实验中，野生型BIV Tat（65-81）肽与BIV TAR结合的K-d约为50 nM。）核磁共振结果表明，高亲和BIV-Tat模拟物在自由溶液中呈稳定的发夹构象。这种模拟物中的氨基酸取代被证明会影响发夹结构并破坏与RNA的结合。这个构象受限的肽拟物家族提供了对与TAR RNA结合的结构要求的见解，并为设计对BIV和HIV TAR RNA具有更高抑制活性和特异性的新配体提供了基础。
An approach is described to the design of beta-hairpin peptidomimetic ligands for bovine immunodeficiency virus (BIV) Tat protein, which inhibit binding to its transactivator response element (TAR) RNA. A library of peptidomimetics was derived by grafting onto a hairpin-inducing D-Pro-L-Pro template sequences related to the RNA recognition element in Tat. One hairpin mimetic was identified that binds tightly (K-d approximate to 150 nM) to BIV TAR, and another that binds also to HIV-1 TAR RNA (K-d approximate to 1-2 muM). (In the same assay, the wild-type BIV Tat(65-81) peptide binds to BIV TAR with K-d approximate to 50 nM.) The high-affinity BIV-Tat mimetic was shown to adopt a stable beta-hairpin conformation in free solution by NMR methods. Amino acid substitutions in this mimetic were shown to impact on the hairpin structure and to disrupt binding to the RNA. This family of conformationally constrained peptidomimetics affords insights into the structural requirements for binding to TAR RNA and provides a basis for the design of new ligands with increased inhibitory activity and specificity to both BIV and HIV TAR RNAs.