De Novo Design, Synthesis, and Function of Semiartificial Myoglobin Conjugated with Coiled-Coil Two-α-Helix Peptides
De Novo Design, Synthesis, and Function of Semiartificial Myoglobin Conjugated with Coiled-Coil Two-α-Helix Peptides
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卷曲螺旋二-α-螺旋肽缀合的半人工肌红蛋白的从头设计、合成和功能
DOI：
10.1002/chem.200306068
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Yoshikawa
中科院分区：
文献类型：
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作者：
S. Sakamoto;A. Ito;K. Kudo;S. Yoshikawa
利用异链卷曲螺旋肽的自组装，成功地在肌红蛋白（Mb）表面引入黄素发色团并通过黄素进行有效的电子转移（ET）反应。我们制备了一种半人工 Mb，命名为 Mb-1alphaK，其中两亲性阳离子 α-螺旋肽与丙酸血红素 (Heme-1alphaK) 缀合。 Heme-1alphaK 在 1alphaK 肽序列的 N 末端有一个共价结合的铁原卟啉 IX（血红素）。该序列被设计为在平行方向的对应两亲性和阴离子 1alphaE 肽序列存在的情况下形成异链卷曲螺旋。还制备了两种肽Fla(1)-1alphaE和Fla(31)-1alphaE，两者均掺入10-甲基异咯嗪部分作为人工黄素分子(Fla=2-[7-(10-甲基)异咯嗪基]-2-氧代乙基)。 Heme-1alphaK 成功插入脱辅基肌红蛋白中，得到 Mb-1alphaK。 Mb-1alphaK 识别黄素修饰肽并形成双α螺旋结构。此外，还观察到从还原烟酰胺腺嘌呤二核苷酸通过黄素单元到血红素中心的有效 ET。 Fla(1)-1alphaE 存在时的 ET 速率比 Fla(31)-1alphaE 或不含肽链的等效分子存在时更快。这些结果表明，通过使用特定的肽-肽相互作用可以在 Mb 表面引入功能性发色团。此外，ET率对黄素位置的依赖性表明，血红素活性位点和黄素发色团之间的距离是由所设计的多肽的三维结构调节的。
The introduction of a flavin chromophore on the myoglobin (Mb) surface and an effective electron-transfer (ET) reaction through the flavin were successfully achieved by utilizing the self-assembly of heterostranded coiled-coil peptides. We have prepared a semiartificial Mb, named Mb-1alphaK, in which an amphiphilic and cationic alpha-helix peptide is conjugated at the heme propionate (Heme-1alphaK). Heme-1alphaK has a covalently bound iron-protoporphyrin IX (heme) at the N terminus of a 1alphaK peptide sequence. This sequence was designed to form a heterostranded coiled-coil in the presence of a counterpart amphiphilic and anionic 1alphaE peptide sequence in a parallel orientation. Two peptides, Fla(1)-1alphaE and Fla(31)-1alphaE, both incorporating a 10-methylisoalloxazine moiety as an artificial flavin molecule, were also prepared (Fla=2-[7-(10-methyl)isoalloxazinyl]-2-oxoethyl). Heme-1alphaK was successfully inserted into apomyoglobin to give Mb-1alphaK. Mb-1alphaK recognized the flavin-modified peptides and a two-alpha-helix structure was formed. In addition, an efficient ET from reduced nicotinamide adenine dinucleotide to the heme center through the flavin unit was observed. The ET rate was faster in the presence of Fla(1)-1alphaE than in the presence of Fla(31)-1alphaE or the equivalent molecule that has no peptide chain. These results demonstrate that the introduction of a functional chromophore on the Mb surface can be achieved by using specific peptide-peptide interactions. Moreover, the dependence of the ET rate on the position of the flavin indicated that the distance between the heme active site and the flavin chromophore was regulated by the three-dimensional structure of the designed polypeptide.