DESIGN OF A 4-HELIX BUNDLE PROTEIN - SYNTHESIS OF PEPTIDES WHICH SELF-ASSOCIATE INTO A HELICAL PROTEIN
DESIGN OF A 4-HELIX BUNDLE PROTEIN - SYNTHESIS OF PEPTIDES WHICH SELF-ASSOCIATE INTO A HELICAL PROTEIN
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DOI：
10.1021/ja00256a032
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发表时间：
1987-10-28
影响因子：
15
通讯作者：
DEGRADO, WF
中科院分区：
文献类型：
--
作者：
HO, SP;DEGRADO, WF
描述了一种用于设计4-螺旋束蛋白的增量合成方法。在二级结构预测规则和模型建立的基础上，设计了两个两亲性的16个氨基酸残基的多肽，n，A和aqB，使它们形成n-螺旋，并在溶液中协同四聚化（得到稳定的4-螺旋结构）。通过化学方法合成了这些肽，并通过分子量测定和圆二色谱研究证实了它们在变性剂存在和不存在下形成稳定的螺旋四聚体的能力。两种肽的四聚化自由能被确定为约为-20千卡/摩尔。在工作的第二阶段，在两个n，B肽的序列之间插入短肽连接，试图设计4-螺旋束结构中两个螺旋对之间的共价交联。合成了两种肽α、α-和α 1B-Pro-Arg-Arg-α 1B，并探测了它们形成二聚体聚集体（4-螺旋结构）的趋势。发现肽nB-Pro-nB产生三聚体聚集体而不是预期的二聚体结构。在环中掺入带电荷的精氨酸残基实现了期望的结果：随后的肽，-Pro-Arg-Arg-，在溶液中形成稳定的螺旋二聚体。
An incremental synthetic approach is described for the design of a 4-helix bundle protein. On the basis of secondary structure prediction rules and model building, two amphiphilic 16-residue peptides,«, A and aqB, were designed toform «-helices that would cooperatively tetramerize (give stable 4-helix structures) in solution. Thepeptides were synthesized by chemical methods, and their ability to form stable helical tetramers was confirmed by molecular weight determinationsand circular dichroism studies in thepresence and absence of denaturant. The free energy of tetramerization of both peptides was determined to be on the order of-20 kcal/mol. In the second stage of the work, short peptidic links were inserted between the sequence of two «, B peptides in an attempt to design a covalent cross-link between two of the helical pairs in the 4-helix bundle structure. Two peptides,«,--, and a1B-Pro-Arg-Arg-a1B, were synthesized, and their tendency to form dimeric aggregates (4-helix structures) was probed. The peptide «jB-Pro-^ was found to give trimeric aggregates rather than the expected dimeric structures. Incorporation of charged arginine residues in the loop achieved the desired result: the ensuing peptide,,-Pro-Arg-Arg-,, forms stable helical dimers in solution.