Dolphin Gunnar T
Department of Chemistry-IFM, Linköping University, 58183 Linköping, Sweden.
J Am Chem Soc. 2006 Jun 7;128(22):7287-90. doi: 10.1021/ja060524k.
The ultimate goals of de novo protein design are the construction of novel tertiary structures and functions. Here is presented the design and synthesis of a uniquely branched three-helix bundle that folds into a well-folded dimeric protein. The branching of this protein was performed by the method of native chemical ligation, which provides a chemoselective and stable amide bond between the unprotected fragments. This ligation strategy was possible by the presented facile preparation of a peptide (43 amino acids) with a specific side chain thioester, which is synthesized by general Fmoc solid phase peptide synthesis. From the presented structural analysis, it is seen that the folded protein is present as a stable and highly helical dimer, thus forming a six-helix bundle. This unique tertiary structure, composed of a dimer of three individual alpha-helices branched together, offers different possibilities for protein engineering, such as metal and cofactor binding sites, as well as for the construction of novel functions.
从头设计蛋白质的最终目标是构建新的三级结构和功能。本文介绍了一种独特分支的三螺旋束的设计与合成，该三螺旋束折叠成一种折叠良好的二聚体蛋白质。这种蛋白质的分支是通过天然化学连接法实现的，该方法能在未保护的片段之间提供化学选择性且稳定的酰胺键。通过本文介绍的简便方法制备具有特定侧链硫酯的肽（43个氨基酸），使得这种连接策略成为可能，该肽是通过通用的Fmoc固相肽合成法合成的。从本文给出的结构分析可以看出，折叠后的蛋白质以稳定且高度螺旋的二聚体形式存在，从而形成一个六螺旋束。这种独特的三级结构由三个单独的α螺旋分支在一起形成二聚体组成，为蛋白质工程提供了不同的可能性，比如金属和辅因子结合位点，以及构建新功能。
