呼吸器複合体Iによる生物学的エネルギー変換におけるキノールアニオンの触媒的関連性
Oleksii Zdorevskyi1, Johannes Laukkanen1, Vivek Sharma1,2
1Department of Physics, University of Helsinki Helsinki Finland oleksii.zdorevskyi@helsinki.fi vivek.sharma@helsinki.fi.
Chemical science
|February 12, 2026
まとめ
呼吸器複合体Iのセミキノンはアニオンであり,閉じ込められ,ユビキノールアニオンはプロトンポンプを駆動するために押し出されます. これは,細胞呼吸におけるキノン・レドックス化学に関する新しい洞察を明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- コンピューティング・ケミストリー
背景:
- キノンのリドックス化学は,細胞呼吸とATP合成に不可欠です.
- コンプレックスIにおけるウビキノン還元は,ミトコンドリアの電子輸送鎖の重要なステップである.
研究 の 目的:
- 複合体Iにおけるウビキノン還元のリドックスメカニズムを解明する.
- セミキノンおよびユビキノール中間物質の性質を調査する.
- プロトンポンプを駆動するこれらの中間物質の役割を理解する.
主な方法:
- 古典的およびハイブリッドのQM/MMシミュレーション.
- 無料エネルギーの計算.
- 高解像度の冷凍-EM構造の分析.
主要な成果:
- コンプレックスIのセミキノン種はアニオン性であり,活性部位に閉じ込められている.
- メタステーブルなユビキノールアニオンが形成され,結合室から静電的に押し出されます.
- ヒスティジンのタウトメリゼーションを含むプロトンの再配置は,ユビキノン還元中に発生します.
結論:
- この発見は,コンプレックスIにおけるキノン・レドックス化学の既存のモデルに異議を唱えている.
- 陽子結合電子伝送の詳細なメカニズム図が提供されています.
- この研究は,野生型と突然変異の条件について,検証可能な仮説を提供している.
関連する概念動画
02:08Gene Conversion
10.7K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
10.7K
02:08Gene Conversion
3.1K
3.1K
01:21Free Energy
52.3K
Free energy—abbreviated as G for the scientist Gibbs who discovered it—is a measurement of useful energy that can be extracted from a reaction to do work. It is the energy in a chemical reaction that is available after entropy is accounted for. Reactions that take in energy are considered endergonic and reactions that release energy are exergonic. Plants carry out endergonic reactions by taking in sunlight and carbon dioxide to produce glucose and oxygen. Animals, in turn, break...
52.3K
02:56Free Energy and Equilibrium
27.3K
The free energy change for a process may be viewed as a measure of its driving force. A negative value for ΔG represents a driving force for the process in the forward direction, while a positive value represents a driving force for the process in the reverse direction. When ΔGrxn is zero, the forward and reverse driving forces are equal, and the process occurs in both directions at the same rate (the system is at equilibrium).
Recall that Q is the numerical value of the mass action...
Recall that Q is the numerical value of the mass action...
27.3K
02:39Gibbs Free Energy
39.4K
One of the challenges of using the second law of thermodynamics to determine if a process is spontaneous is that it requires measurements of the entropy change for the system and the entropy change for the surroundings. An alternative approach involving a new thermodynamic property defined in terms of system properties only was introduced in the late nineteenth century by American mathematician Josiah Willard Gibbs. This new property is called the Gibbs free energy (G) (or simply the free...
39.4K
02:59Biological Effects of Radiation
18.1K
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they...
18.1K