関連する実験動画
Updated: Aug 12, 2026
11:37
Analyzing Protein Dynamics Using Hydrogen Exchange Mass Spectrometry
Published on: November 29, 2013
水素結合による電子結合の直接評価:生物学的電子伝送への影響
P J de Rege1, S A Williams, M J Therien
1Department of Chemistry, University of Pennsylvania, Philadelphia 19104-6323, USA.
Science (New York, N.Y.)
|September 8, 1995
まとめ
水素結合は,超分子系におけるシグマ結合よりも効果的に電子結合を促進する. この発見は,既存の理論に異議を唱え,生物学的電子伝送における水素結合の重要性を強調しています.
科学分野:
- 超分子化学 超分子化学
- フォトケミストリー フォトケミストリー
- 生物物理化学 生物物理化学
背景:
- 電子の移転は生物学的プロセスに不可欠である.
- 電子結合メカニズムの理解は,電子伝送率の予測に不可欠です.
- 以前の理論は,電子結合における水素結合の役割をしばしば過小評価していた.
研究 の 目的:
- 超分子バイクロモフォア系を合成し,特徴づけること.
- 水素,シグマ,π結合の電子結合強さを定量的に比較する.
- 光誘導による電子移転を媒介する水素結合の役割を調査する.
主な方法:
- 亜鉛 (II) と鉄 (III) ポルフィリンシステムの合成.
- 激励状態を生成するためのレーザーフラッシュ光分解.
- 電子伝送速度定数の測定. 電子伝送速度定数の測定.
主要な成果:
- 水素結合による電子結合は,シグマ結合よりも強いことが判明した.
- 光誘発電子伝送速度は,3つの異なる超分子システムで測定されました.
- この結果は,電子結合経路に関する確立された理論と矛盾しています.
結論:
- 水素結合は,生物学的電子伝送において重要な役割を果たします.
- 現在の理論的モデルは,生物学的システムにおける電子トンネリングを正確に予測するために精錬する必要があるかもしれません.
- この研究は,タンパク質経由の電子移転を分析するための重要なデータを提供します.
さらに関連する動画
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
関連する概念動画
02:35Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
01:17Coupled Reactions
Cellular processes such as building and breaking down complex molecules occur through stepwise chemical reactions. Some of these chemical reactions are spontaneous and release energy, whereas others require energy to proceed. Cells often couple the energy-releasing reaction with the energy-requiring one to carry out important cell functions.
Energy in adenosine triphosphate or ATP molecules is easily accessible to do work. ATP powers the majority of energy-requiring cellular reactions. Cells...
Energy in adenosine triphosphate or ATP molecules is easily accessible to do work. ATP powers the majority of energy-requiring cellular reactions. Cells...
01:17Spin–Spin Coupling: One-Bond Coupling
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
01:27¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.