Design and synthesis of flavin-conjugated peptides and assembly on a gold electrode
作者:Seiji Sakamoto、Haruhiko Aoyagi、Naotoshi Nakashima、Hisakazu Mihara
DOI:10.1039/p29960002319
日期:——
Flavin-conjugated peptides composed of one or two amphiphilic α-helix segments have been designed and synthesized. 7-Acetyl-10-methylisoalloxazine (Fla) as a model flavin has been introduced on the side chain of Cys at the 6th, 7th or 8th position of each α-helical 14-peptide. A CD study in aqueous solution revealed that the position of Fla on the peptide strongly influenced the peptide secondary structure. Additionally, CD spectra indicated that the Fla in the peptides was oriented in a different manner depending on the position when the peptide took on the α-helix structure. Furthermore, the flavinconjugated peptides have been adsorbed on a gold surface through the sulfide linkage, as a basic study for peptidyl devices in the future. By the use of Fla as an electrochemical probe, we examined properties of the peptide assembled on the gold electrode. The cyclic voltammetry measurements revealed that the functional group, Fla, was redox-active on the electrode and the peptide bound on the surface in a monolayer. Moreover, the flavin-conjugated peptide could mediate the electron transfer from the electrode to Fe(CN)63– ion or cytochrome c in a vector manner. The redox-active probe, Fla, has been demonstrated to provide significant information about the assembly and function of the α-helix peptides on the gold electrode surface by electrochemical measurements.
我们设计并合成了由一个或两个两亲性α-螺旋段组成的黄素共轭肽。7-Acetyl-10-methylisoalloxazine (Fla) 作为黄素模型,被引入到每个 α-helical 14 肽的第 6、7 或 8 位 Cys 侧链上。水溶液中的 CD 研究表明,Fla 在肽上的位置对肽的二级结构有很大影响。此外,CD 光谱显示,当肽具有 α 螺旋结构时,肽中 Fla 的取向因位置而异。此外,黄素共轭肽通过硫化物连接被吸附在金表面上,为将来的多肽装置提供了基础研究。通过使用 Fla 作为电化学探针,我们研究了组装在金电极上的多肽的特性。循环伏安法测量结果表明,官能团 Fla 在电极上具有氧化还原活性,多肽以单层形式结合在电极表面。此外,黄素共轭肽能以矢量方式介导电子从电极转移到 Fe(CN)63- 离子或细胞色素 c。通过电化学测量,氧化还原活性探针 Fla 可提供有关金电极表面 α 螺旋肽的组装和功能的重要信息。