ミトコンドリアの電子輸送酵素のダイオードのような行動
A Sucheta1, B A Ackrell, B Cochran
1Department of Chemistry, University of California, Irvine 92717.
Nature
|March 26, 1992
まとめ
ミトコンドリアサクシネート脱水素酵素は,生物学的ダイオードのように作用し,電子の流れを1方向に導きます. 熱力学ではなく,この運動ゲーティングが,生物学的電子輸送の方向性を強制する.
科学分野:
- バイオケミストリー バイオケミストリー
- ミトコンドリアの機能
- 酵素の動力学について
背景:
- ミトコンドリアは,トリカルボキシル酸サイクルにおける電子移転のために,サクシネート-ウビキノン酸化還元酵素を用いる.
- サクシネート酸化からの電子は,通常,キノンプールに転送されます.
研究 の 目的:
- 溶性サッキナート脱水素酵素の方向性電子流の性質を調査する.
- 熱力学ではなく,運動的要因が生物学的電子輸送の方向性を支配するかどうかを判断する.
主な方法:
- グラファイト電極を用いて,サクシネート脱水素酵素の溶解形態を研究した.
- 継続的に変動する電気化学的ポテンシャル下で測定された酵素回転量.
- 酵素と電極の間の電子交換運動を分析した.
主要な成果:
- サッキナート脱水素酵素はダイオードのような行動を示し,一方的な電子の流れを可能にしました.
- 酵素のフーマレートを減少させる能力 (逆反応) は,過剰ポテンシャルの増加によって著しく阻害されました.
- この運動ゲーティングは,酵素結合群の還元酸化状態への依存を示唆する.
結論:
- サクシネート脱水素酵素は,運動的メカニズムを通じて片方向の電子輸送を強制する.
- この発見は,生物学的電子輸送システムにおける動的方向性を示しています.
- 酵素のリドックス状態は,基板結合や産物放出などの速度制限のステップに影響する可能性があります.
関連する概念動画
Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.Electrons Orbit the NucleusElectrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus...
The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
Electron Behavior
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
Electron Transport Chain Components
The electron transport chain (ETC) is a crucial metabolic pathway that facilitates energy conversion in prokaryotic and eukaryotic cells. In eukaryotes, the ETC comprises four membrane-associated protein complexes in the inner mitochondrial membrane. In prokaryotes, the ETC in the plasma membrane can vary in composition, with fewer or different complexes depending on the organism and environmental conditions. These complexes transfer electrons from electron donors, such as NADH and FADH2, to...


