Structure-based engineering of internal cavities in coiled-coil peptides.
Structure-based engineering of internal cavities in coiled-coil peptides.
复制标题
卷曲螺旋肽内腔的基于结构的工程。
DOI：
10.1021/bi050742a
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发表时间：
2005
期刊：
影响因子：
2.9
通讯作者：
Ghadiri,MReza
中科院分区：
文献类型：
--
作者：
Yadav,ManeeshK;Redman,JamesE;Leman,LukeJ;Alvarez-Gutiérrez,JuliettaM;Zhang,Yanming;Stout,CDavid;Ghadiri,MReza
空腔和裂缝通常是天然酶或受体与其相应的底物或配体分子之间相互作用的重要位点，并取代了有助于人工催化剂和受体工程化的分子表面类型。即便如此，所设计的腔的结构特征是罕见的。为了解决这个问题，我们进行了一个系统的研究，在四聚体卷曲螺旋肽的疏水核心内的单氨基酸取代的结构效应。在埋藏的L9，L16，L23和I26的疏水核心位置的GCN 4为基础的序列含有单一的甘氨酸，丝氨酸，丙氨酸，或苏氨酸氨基酸取代的肽合成和研究的溶液相和晶体学技术。所有肽均采用预期的四聚体状态，并含有大小为80至370 μ m 3的隧道或内腔。含有L16G取代的两个密切相关的序列，其中一个采用反平行构型，其中一个采用平行构型，说明可以从相同的核心取代工程化不同体积和形状的空腔。最后，我们证明了两个肽（L9G和L9A）结合的小分子碘苯时，结晶过程中存在，留下完整的一般肽四级结构，但改变局部肽构象和某些超螺旋参数。这些高分辨率的描述不同的分子表面内的溶剂封闭的内部空腔说明了宽度的设计空间，甚至密切相关的肽，并提供了有价值的模型从头螺旋蛋白的工程。
Cavities and clefts are frequently important sites of interaction between natural enzymes or receptors and their corresponding substrate or ligand molecules and exemplify the types of molecular surfaces that would facilitate engineering of artificial catalysts and receptors. Even so, structural characterizations of designed cavities are rare. To address this issue, we performed a systematic study of the structural effects of single-amino acid substitutions within the hydrophobic cores of tetrameric coiled-coil peptides. Peptides containing single glycine, serine, alanine, or threonine amino acid substitutions at the buried L9, L16, L23, and I26 hydrophobic core positions of a GCN4-based sequence were synthesized and studied by solution-phase and crystallographic techniques. All peptides adopt the expected tetrameric state and contain tunnels or internal cavities ranging in size from 80 to 370 Å3. Two closely related sequences containing an L16G substitution, one of which adopts an antiparallel configuration and one of which adopts a parallel configuration, illustrate that cavities of different volumes and shapes can be engineered from identical core substitutions. Finally, we demonstrate that two of the peptides (L9G and L9A) bind the small molecule iodobenzene when present during crystallization, leaving the general peptide quaternary structure intact but altering the local peptide conformation and certain superhelical parameters. These high-resolution descriptions of varied molecular surfaces within solvent-occluded internal cavities illustrate the breadth of design space available in even closely related peptides and offer valuable models for the engineering of de novo helical proteins.