メタロチャペロンSlyDのNi (II) 結合特性について
Harini Kaluarachchi1, Duncan E K Sutherland, Alex Young
1Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
Journal of the American Chemical Society
|December 2, 2009
まとめ
エシェリキア・コーライ・メタルロチャペロンSlyDは,高親和度で最大7個のニッケルイオンに結合する. このニッケル結合は,SlyDDに影響を与える.
科学分野:
- バイオケミストリー バイオケミストリー
- メタルプロテインの研究
- 分子生物学は分子生物学である.
背景:
- メタロチャペロンは,金属コファクターのタンパク質への伝達を促進します.
- ニッケルは細胞のプロセスに不可欠ですが,過剰に有毒です.
- Escherichia coliのSlyDタンパク質は,ニッケルホメオスタシスと[Ni-Fe]-ヒドロゲナーゼ組成に関与しています.
研究 の 目的:
- エシェリキヤ大腸SlyD.のニッケル結合特性を調査する.
- ニッケル蓄積と代謝におけるSlyDの役割を明らかにする.
- スライドに対するニッケル結合の構造的,機能的な影響を理解する.
主な方法:
- 非共性金属-タンパク質複合体を分析するための電子スプレーイオン化質量スペクトロメトリ (ESI-MS).
- 金属による形状の変化を観察するための構造分析技術.
- ニッケルイオンの協調幾何学を決定するX線吸収スペクトロスコーピー (XAS).
- ニッケル結合の重要な残留物を特定するためにSlyD変異体の特徴づけ.
主要な成果:
- SlyDは7個のニッケルイオンまで非協力的に結合し,サブミクロモラー近親性を有する.
- ニッケル結合は,SlyDの微妙な構造変化を誘導し,N端末とC端末ドメインの両方に影響を及ぼします.
- ニッケル結合部位にはベータターン形成があり,システイン残留物は結合親和性と結合能力を高めます.
- SlyDは,多様なニッケルイオン座標幾何学と数字を展示しています.
結論:
- SlyDは,Escherichia coliにおけるマルチニッケルイオン結合メタロチャペロンとして機能する.
- このタンパク質は,ニッケルホメオスタシスとメタロ酵素組成において重要な役割を果たします.
- 構造的な柔軟性と特定の残留物は,SlyDのニッケル結合能力に寄与しています.
さらに関連する動画
11:38Quantifying the Binding Interactions Between Cu(II) and Peptide Residues in the Presence and Absence of Chromophores
Published on: April 5, 2022
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
関連する概念動画
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
00:49Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
00:56Extraction: Advanced Methods
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...