キネシンによるプロセス性ATP水解の経路
S P Gilbert1, M R Webb, M Brune
1Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802.
Nature
|February 23, 1995
まとめ
キネシン (kinesin) とは
科学分野:
- 分子モーター機能は分子モーター機能である.
- バイオケミストリー バイオケミストリー
- 細胞生物学 細胞生物学
背景:
- キネシンは,マイクロチューブルに沿って移動するモータータンパク質です.
- キネシン ATP 酵素のサイクルを理解することは,その運動性を説明する上で極めて重要です.
- キネシンの機能は,骨格のミオシンと比較されます.
研究 の 目的:
- キネシンの微小管との相互作用の運動学を直接測定する.
- キネシンATPアゼサイクルのメカニズムを解明する.
- キネシンと骨格ミオシンの運動性の違いを説明するために.
主な方法:
- キネシンと微小管の相互作用の直接的運動測定.
- リン酸塩とADPの放出を含むキネシンのATP水解周期の分析.
- マイクロチューブルへのキネシン再結合の調査.
主要な成果:
- ATPの水解後に微小管からキネシン解離が速度を制限するステップです.
- キネシンプロセッシビティ (サイト毎のATP水解) は,塩分濃度が増加するにつれて減少する.
- キネシン-ADPのマイクロチューブルへの再結合は迅速であり,解離状態の時間を最小限に抑えます.
結論:
- この研究では,キネシンATPアゼサイクルメカニズムが定義されています.
- 解離運動学は,キネシンの機能周期と運動性を説明する.
- 解離と再結合の動態の違いは,骨格のミオシンと比較して運動性の変動を説明する.
関連する概念動画
01:08Hydrolysis of ATP
The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process called hydrolysis. This reaction liberates the energy in the bonds for use in the cell—for instance, to synthesize proteins from amino acids.
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
01:08Hydrolysis of ATP
The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process called hydrolysis. This reaction liberates the energy in the bonds for use in the cell—for instance, to synthesize proteins from amino acids.
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:32Microtubule Associated Motor Proteins
Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
01:43The 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,...