Oligomerization of uniquely folded mini-protein motifs:: Development of a homotrimeric ββα peptide
Oligomerization of uniquely folded mini-protein motifs:: Development of a homotrimeric ββα peptide
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DOI：
10.1021/ja004292f
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发表时间：
2001-05-02
影响因子：
15
通讯作者：
Imperiali, B
中科院分区：
文献类型：
--
作者：
Mezo, AR;Cheng, RP;Imperiali, B
最近报道了离散折叠的同源三聚体β β α基序（BBAT 1）的发现（J. Am.化学分析2001，123，1002-1003）。本文描述了导致BBAT 1分离的小肽库的设计、合成和分析。基于BBA 5的单体序列的β β α肽（Folding DES. 1998，120，95-103），以包括邻氨基苯甲酸/硝基酪氨酸荧光猝灭对，从而快速检测肽间缔合。在合成的第一代肽中，连接P-发夹与α-螺旋的环区域中的截短揭示了环中的两个残基缺失促进了肽间缔合，如通过荧光猝灭检测到的。随后合成22个环截短的β β α肽的额外文库，以包括各种序列突变，以增强观察到的肽-肽结合。从荧光猝灭筛选中，发现肽B2具有最强的荧光猝灭反应，表明肽-肽结合较强。由于肽B2的溶解性差，将环中9位的S-甲基化半胱氨酸用甘氨酸取代以产生肽BBAT 1，其具有大大改善的水溶性并形成离散的三聚体。这种寡聚体β β α结构的成功设计将可能有助于设计更复杂的α-β超结构，并进一步了解控制α-β蛋白质界面处蛋白质-蛋白质相互作用的因素。
The discovery of a discretely folded homotrimeric beta beta alpha motif (BBAT1) was recently reported (J. Am. Chem. Sec. 2001, 123, 1002-1003). Herein the design, synthesis, and analysis of a small library of peptides which led to the isolation of BBAT1 is described. beta beta alpha peptides based on the monomeric sequence of BBA5 (Folding DES. 1998, 120, 95-103) were synthesized to include the anthranilic acid/nitrotyrosine fluorescence quenching pair to rapidly detect interpeptide association. In the first generation of peptides synthesized, truncations in the loop region connecting the P-hairpin to the a-helix revealed that a two-residue deletion in the loop promoted an interpeptide association as detected by fluorescence quenching. An additional library of 22 loop-truncated beta beta alpha peptides was subsequently synthesized to include a variety of sequence mutations in an effort to enhance the observed peptide-peptide binding. From the fluorescence quenching screen, peptide B2 was found to possess the strongest fluorescence-quenching response, indicative of a strong peptide-peptide association. Due the poor solubility of peptide B2, the S-methylated cysteine at position 9 in the loop was substituted with a glycine to generate peptide BBAT1 which possessed greatly improved water solubility and formed discrete trimers. The successful design of this oligomeric beta beta alpha structure will likely aid the design of more complex alpha-beta superstructures and further our understanding of the factors controlling protein-protein interactions at alpha-beta protein interfaces.