2020年6月
Intrahelical Interactions in an alpha-Helical Coiled Coil Determine the Structural Stability of Tropomyosin
BIOCHEMISTRY
- ,
- ,
- ,
- ,
- ,
- ,
- ,
- 巻
- 59
- 号
- 23
- 開始ページ
- 2194
- 終了ページ
- 2202
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/acs.biochem.0c00203
- 出版者・発行元
- AMER CHEMICAL SOC
Tropomyosin (Tpm) is a two-stranded parallel alpha-helical coiled-coil protein, and studying its structure is crucial for understanding the nature of coiled coils. Previously, we found that the N-terminal half of the human skeletal muscle alpha-Tpm (alpha-Tpm 140) was less structurally stable in the presence of phosphate ions than the coiled-coil protein carrier (CCPC) 140 variant with 18 mutated residues, in which all amino acid residues located at the interface between the two alpha-helices were completely conserved. A classical hypothesis explains that interhelical interactions stabilize the coiled-coil structure. In this study, we tested the hypothesis that the structural stability of Tpm and its variant is governed by the binding of multivalent ions that form a bridge between charged side chains located at positions b, c, and f of the heptad repeat on a single alpha-helical chain. We found that the structural stability of alpha-Tpm 140 and CCPC 140 markedly increased upon addition of divalent cations and divalent anions, respectively. We also clarified that the structural stability of the alpha-Tpm 140/CCPC 140 heteromeric coiled-coil molecule was governed by the stability of a less stable alpha-helical chain. These results demonstrated that the entire structural stability of Tpm is determined by the stability of a single alpha-helix. Our findings provide new insights into the study of the structure of coiled-coil proteins.
- リンク情報
- ID情報
-
- DOI : 10.1021/acs.biochem.0c00203
- ISSN : 0006-2960
- Web of Science ID : WOS:000542225300009