フォスフォリル移転反応のペンタコヴァラントリン中介物質である
Sushmita D Lahiri1, Guofeng Zhang, Debra Dunaway-Mariano
1Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118-2394, USA.
まとめ
研究者らは,酵素触媒における高エネルギー中間物質の原子構造を捉えた. これは,酵素がどのように移行状態を安定させるかを明らかにし, fosforyl 移転反応におけるそれらの驚くべき触媒力を説明します.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 酵素学 酵素学とは
背景:
- 酵素は強力な生物学的触媒であり,高エネルギー反応状態を安定させることで,著しい速度向上を達成します.
- 酵素機構を理解するには,これらの一時的な高エネルギー中間物質を視覚化する必要があります.
研究 の 目的:
- 酵素によるフォスフォリル移転中の高エネルギー反応中間物質の原子解像度構造を決定する.
- 酵素活性部位における安定した移行状態を観察することによって,触媒力のメカニズムを解明する.
主な方法:
- リン酸化ベータ-フォスフォグルコムターゼの結晶化とMg (II) コファクターと基板 (グルコース1-リン酸またはグルコース6-リン酸).
- 原子解像度 (1.2および1.4アングストーム) までの酵素-Mg(II) -グルコース1,6-(bis) フォスファート複合体のX線微分分析.
主要な成果:
- 安定したペンタコヴァレンントフォスフォラン中間物の原子構造が明らかになった.
- この中間物質は,グルコース1,6-(bis) フォスファートからアクティブサイトアスパルテート残留物 (Asp8) へのフォスフォリル移転中に形成されます.
結論:
- この研究は,酵素触媒における安定した高エネルギー中間物質の直接的な構造的証拠を提供します.
- この安定化メカニズムは,ペンタコヴァレンントのフォスフォランを伴うもので,フォスフォリル移転における酵素の触媒効率の鍵である.
関連する概念動画
Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Energy Transfer in Chemical Reactions
Chemical reactions require sufficient energy to cause the matter to collide with enough precision and force that old chemical bonds can be broken and new ones formed. In general, kinetic energy is the form of energy powering any type of matter in motion. Imagine a person building a brick wall. The energy it takes to lift and place one brick on top of another is the kinetic energy—the energy matter possesses because of its motion. Once the wall is in place, it stores potential energy. Potential...
Transport Number
The transport number is the fraction of the total current carried by an ion in an electrolyte solution. It is defined as the ratio of the current carried by a specific ion to the total current flowing through the solution. The transport number, t, is central to understanding ionic mobility, which describes how fast an ion moves under the influence of an electric field. This link connects the physical behavior of ions in solution to the chemical processes that occur during electrochemical...
Transition State Theory
Transition-state theory, also known as activated-complex theory, provides a molecular-level explanation of reaction rates in both gas-phase and solution-phase reactions. It extends earlier kinetic models by considering the formation of a short-lived, high-energy configuration during a reaction.The progress of a chemical reaction can be represented using a reaction profile, which plots potential energy against the reaction coordinate. As two reactant molecules approach one another, their...


