酵素の固有のダイナミクスは,触媒の基礎となっている
Elan Z Eisenmesser1, Oscar Millet, Wladimir Labeikovsky
1Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA.
Nature
|November 4, 2005
まとめ
酵素触媒はタンパク質の柔軟性に依存しています. 研究によると,酵素機能に必要な動きは固有であり,自由酵素に先行して存在し,反応速度を制限する可能性がある.
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:
- 酵素触媒には,折りたたまれたタンパク質内の反応性原子が含まれています.
- 酵素の機能を理解することは,伝統的に化学反応と静的構造に焦点を当てています.
- 酵素触媒におけるタンパク質ダイナミクスの役割は,ますます認識されています.
研究 の 目的:
- タンパク質の柔軟性と酵素機能の関連性を調査する.
- 触媒処理中のプロリルシス・トランス・イソメラーゼ・サイクロフィリンA (CypA) の動態を特徴づける.
- 酵素の動きが固有の性質であるか,または基板結合によって誘発されるかどうかを判断する.
主な方法:
- 核磁共振 (NMR) のリラクゼーション実験は,CypAのダイナミクスを研究するために使用されました.
- CypA.の基質フリー状態と触媒活性状態の分析
- 集団運動を調査するためにCypAの変異形態を利用した.
主要な成果:
- 触媒作用に不可欠な酵素の動きは,CypA.の基板のない状態で検出されました.
- これらの動きは,触媒の回転率に似た周波数で起こります.
- タンパク質のダイナミクスは,活性部位に限定されず,より広範なネットワークに広がり,集団的行動を示します.
結論:
- タンパク質の可塑性と既にある集団的動態は,酵素触媒の重要な特徴である.
- これらの内在的運動は,酵素の触媒の回転率を決定したり,制限したりする可能性があります.
- 酵素の進化には,タンパク質の構造とダイナミクスの間の相乗効果的圧力が含まれている可能性が高い.
関連する概念動画
01:13Induced-fit Model
Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
02:34Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
01:22Introduction to Enzymes
The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an enzyme-catalyzed reaction. Wilhelm Kuhne coined the term 'enzyme' in 1877 from the Greek words ‘en’ meaning ‘in’ or ‘within’ and ‘zyme’ meaning ‘yeast.’
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also...
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also...
01:13Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
01:22Introduction To Enzymes
The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an enzyme-catalyzed reaction. Wilhelm Kuhne coined the term 'enzyme' in 1877 from the Greek words ‘en’ meaning ‘in’ or ‘within’ and ‘zyme’ meaning ‘yeast.’
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also...
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also...
01:13Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...