3QL2

Crystal Structure of Ribonuclease A Variant A4C/D83E/V118C

3QL2 の概要

• エントリーDOI: 10.2210/pdb3ql2/pdb
• 関連するPDBエントリー: 3QL1
• 分子名称: Ribonuclease pancreatic, SULFATE ION (3 entities in total)
• 機能のキーワード: ribonuclease a, disulfide bond, salt bridge, stability, folding, proteolysis, site-directed mutagenesis, hydrolase
• 由来する生物種: Bos taurus (bovine)
• 細胞内の位置: Secreted: P61823
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 27708.99

構造登録者

Arnold, U.,Schoepfel, M. (登録日: 2011-02-02, 公開日: 2012-02-29, 最終更新日: 2024-10-30)

主引用文献

Arnold, U.,Schopfel, M.
Significant stabilization of ribonuclease A by additive effects
Febs J., 279:2508-2519, 2012

PubMed Abstract: Among the strategies that employ genetic engineering to stabilize proteins, the introduction of disulfide bonds has proven to be a very potential approach. As, however, the replacement of amino acid residues by cysteines and the subsequent formation of the covalent bond can result in a severe deformation of the parental protein structure, the stabilization effect is strongly context dependent. Alternatively, the introduction of charged amino acid residues at the surface, which may result in the formation of extra ionic interactions or hydrogen bonds, provide propitious means for protein stabilization. The generation of an extra disulfide bond between residues 4 and 118 in ribonuclease A had resulted in a stabilization by 6 °C or 7 kJ mol(-1), which was mainly caused by a deceleration of the unfolding reaction [Pecher, P. & Arnold, U. (2009) Biophys Chem, 141, 21-28]. Here, Asp83 was replaced by Glu resulting in a comparable stabilization. Moreover, combination of both mutations led to an additive effect and the resulting ribonuclease A variant (T(m) ~ 76 °C, ΔG° ~ 53 kJ mol(-1)) is the most stable ribonuclease A variant described so far. The analysis of the crystal structure of A4C/D83E/V118C-ribonuclease A reveals the formation of a salt bridge between the γ-carboxyl group of Glu83 and the ε-amino group of Lys104.

PubMed: 22594773
DOI: 10.1111/j.1742-4658.2012.08632.x

実験手法

X-RAY DIFFRACTION (1.49 Å)