8JZ1

Crystal structure of a single-chain monellin mutant C41V

8JZ1 の概要

• エントリーDOI: 10.2210/pdb8jz1/pdb
• 分子名称: Monellin chain B,Monellin chain A (2 entities in total)
• 機能のキーワード: sweet protein, plant protein
• 由来する生物種: Dioscoreophyllum cumminsii (serendipity berry); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 22447.49

構造登録者

Yasui, N.,Ohnuma, K.,Yamashita, A. (登録日: 2023-07-04, 公開日: 2023-10-11, 最終更新日: 2023-11-01)

主引用文献

Ohnuma, K.,Yamashita, A.,Yasui, N.
Investigating the Effect of Substituting a Single Cysteine Residue on the Thermal Stability of an Engineered Sweet Protein, Single-Chain Monellin.
Protein J., 42:698-708, 2023

PubMed Abstract: Single-chain monellin (SCM) is an engineered protein that links the two chains of monellin, a naturally sweet-tasting protein. This protein is an attractive candidate for use as a sugar replacement in food and beverages and has numerous other applications. Therefore, generating SCM mutants with improved stability is an active area of research to broaden the range of its potential applications. In this study, we focused on the Cys41 residue of SCM, which is a single cysteine residue present at a structurally important position. This residue is often substituted with Ser. However, this substitution may destabilize SCM because Cys41 is buried in the hydrophobic core of the protein. Therefore, we designed mutants that substituted Ala, Val, and Leu for this residue, namely C41A, C41V, and C41L. We characterized these three mutants, SCM C41S, and wild type (WT). Differential scanning fluorimetric analysis revealed that substituting Cys41 with Ala or Val increased the thermal stability of SCM, while substitution with Ser or Leu decreased its stability. Determination of the crystal structures of SCM C41A and C41V mutants revealed that the overall structures and main chain structures around the 41st residue of both mutants were almost identical to the WT. On the other hand, the orientations of the amino acid side chains near the 41st residue differed among the SCM variants. Taken together, our results indicate that substituting Cys41 with Ala or Val increases the stability of SCM and provide insight into the structural basis of this improvement.

PubMed: 37737932
DOI: 10.1007/s10930-023-10154-0

実験手法

X-RAY DIFFRACTION (1.239 Å)