A hydrogen bond surrogate approach for stabilization of short peptide sequences in alpha-helical conformation.
A hydrogen bond surrogate approach for stabilization of short peptide sequences in alpha-helical conformation.
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DOI：
10.1021/ar700264k
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发表时间：
2008-10
影响因子：
18.3
通讯作者：
Arora PS
中科院分区：
文献类型：
--
作者：
Patgiri A;Jochim AL;Arora PS
α-螺旋构成最大的一类蛋白质二级结构，在介导蛋白质-蛋白质相互作用中发挥重要作用。开发短 α 螺旋的稳定模拟物对于抑制蛋白质-蛋白质相互作用具有不可估量的价值。本报告描述了我们在开发一种通过主链氢键替代 (HBS) 策略将短肽限制在 α 螺旋构象中的通用方法方面所做的努力。 HBS α-螺旋具有源自闭环复分解反应的碳-碳键，取代了肽 i 和 i + 4 残基之间的 N 端分子内氢键。我们的方法以肽中的螺旋-螺旋转变理论为中心，该理论表明将三个连续氨基酸组织成螺旋方向的能量要求固有地限制了短 α 螺旋的稳定性。 HBS 方法提供预组织的 α 转角，以克服这种内在的成核势垒并启动螺旋形成。 HBS 方法是生成蛋白质受体配体的一种有吸引力的策略，因为将交联放置在螺旋内部不会阻碍分子暴露于溶剂的分子识别表面。我们基于复分解的合成策略采用标准的 Fmoc 固相肽合成方法、树脂和试剂，并为后续的生物物理和生物分析提供足够量的 HBS 螺旋。利用 2D NMR、圆二色光谱和 X 射线晶体学对 HBS α-螺旋进行广泛的构象分析，证实了这些化合物中的 α-螺旋结构。晶体结构表明所有 i 和 i + 4 C=O 和 NH 氢键伙伴都落在完全氢键 α 螺旋预期的距离和角度内。晶体结构中 HBS α 螺旋的主链构象与模型 α 螺旋的主链构象以 0.75 Å 的均方根差异叠加。值得注意的是，HBS 螺旋残基的主链扭转角落在规范 α 螺旋的预期范围内。热变性和化学变性研究表明，HBS 方法可从各种短序列中提供异常稳定的 α 螺旋，这些短序列在极高的温度下在水性缓冲液中保留其螺旋构象。观察到的 HBS 螺旋的高度热稳定性与有核螺旋的理论预测一致。 HBS 方法旨在提供内部约束螺旋，以便螺旋的分子识别表面及其蛋白质结合特性不会受到约束部分的影响。值得注意的是，我们的初步研究表明，HBS 螺旋可以以高亲和力靶向其预期的蛋白质受体。
α-Helices constitute the largest class of protein secondary structures and play a major role in mediating protein-protein interactions. Development of stable mimics of short α-helices would be invaluable for inhibition of protein—protein interactions. This Account describes our efforts in developing a general approach for constraining short peptides in α-helical conformations by a main-chain hydrogen bond surrogate (HBS) strategy. The HBS α-helices feature a carbon-carbon bond derived from a ring-closing metathesis reaction in place of an N-terminal intramolecular hydrogen bond between the peptide i and i + 4 residues. Our approach is centered on the helix-coil transition theory in peptides, which suggests that the energetically demanding organization of three consecutive amino acids into the helical orientation inherently limits the stability of short α-helices. The HBS method affords preorganized α-turns to overcome this intrinsic nucleation barrier and initiate helix formation. The HBS approach is an attractive strategy for generation of ligands for protein receptors because placement of the cross-link on the inside of the helix does not block solvent-exposed molecular recognition surfaces of the molecule. Our metathesis-based synthetic strategy utilizes standard Fmoc solid phase peptide synthesis methodology, resins, and reagents and provides HBS helices in sufficient amounts for subsequent biophysical and biological analyses. Extensive conformational analysis of HBS α-helices with 2D NMR, circular dichroism spectroscopies and X-ray crystallography confirms the α-helical structure in these compounds. The crystal structure indicates that all i and i + 4 C=O and NH hydrogen-bonding partners fall within distances and angles expected for a fully hydrogen-bonded α-helix. The backbone conformation of HBS α-helix in the crystal structure superimposes with an rms difference of 0.75 Å onto the backbone conformation of a model α-helix. Significantly, the backbone torsion angles for the HBS helix residues fall within the range expected for a canonical α-helix. Thermal and chemical denaturation studies suggest that the HBS approach provides exceptionally stable α-helices from a variety of short sequences, which retain their helical conformation in aqueous buffers at exceptionally high temperatures. The high degree of thermal stability observed for HBS helices is consistent with the theoretical predictions for a nucleated helix. The HBS approach was devised to afford internally constrained helices so that the molecular recognition surface of the helix and its protein binding properties are not compromised by the constraining moiety. Notably, our preliminary studies illustrate that HBS helices can target their expected protein receptors with high affinity.
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影响因子：
15
作者：
Gemperli, AC;Rutledge, SE;Schepartz, A
通讯作者：
Schepartz, A
影响因子：
15
作者：
Chapman, RN;Dimartino, G;Arora, PS
通讯作者：
Arora, PS
影响因子：
15
作者：
Austin, RE;Maplestone, RA;Bartlett, PA
通讯作者：
Bartlett, PA
DOI：
10.1073/pnas.86.3.765
发表时间：
1989-02-01
影响因子：
11.1
作者：
KARLE, IL;FLIPPENANDERSON, JL;BALARAM, P
通讯作者：
BALARAM, P
影响因子：
2.7
作者：
Baxter, NJ;Williamson, MP
通讯作者：
Williamson, MP