神経毒素IIは,ダイナミックな核極化NMRによって研究された原生膜のアセチルコリン受容体と結合する
Arne H Linden1, Sascha Lange, W Trent Franks
1Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany.
Journal of the American Chemical Society
|November 2, 2011
まとめ
この研究は,ニコチンアセチルコリン受容体 (nAChR) のような膜タンパク質の構造分析のためのダイナミック核偏振 (DNP) NMRを,浄化なしで実証しています. 最適化されたビラジカル分布は,ネイティブ膜における受容体-リガンド相互作用を研究するための感受性を高めます.
科学分野:
- 膜タンパク質の構造生物学
- 生物物理化学 生物物理化学とは
- 神経科学は神経科学である.
背景:
- 膜タンパク質を本来の環境で研究することは,極めて重要ですが,挑戦的です.
- 浄化はしばしばタンパク質の構造と機能を破壊する.
- ダイナミック・ニュクリア・ポラライゼーション (DNP) NMRは,構造研究の感度を高めます.
研究 の 目的:
- タンパク質浄化なしで膜統合受容体システムの構造研究のためにDNP NMRを使用する可能性を調査する.
- ネイティブ膜におけるニコチンアセチルコリン受容体 (nAChR) と結合した神経毒素IIの固体状態のNMRスペクトルを観察する.
- DNPの偏光剤 (TOTAPOL) の局所化と安定性,およびNMRデータに対するその影響を評価する.
主な方法:
- 固体ダイナミック核極化 (DNP) マジック・アングル・スピニング (MAS) NMRスペクトロスコーピー.
- (13) C-ラベル付ニューロトキシンIIを,ネイティブの膜でnAChRに結合させることを広く利用する.
- DNP強化のためにバイラジカルTOTAPOLを使用する.
主要な成果:
- nAChR-神経毒素II複合体の固体状態のNMRスペクトルが,ネイティブの膜で得られた.
- ビラジカルであるTOTAPOLは,膜とタンパク質の表面に局所することが観察されました.
- 活性ビラジカルの最適な分布は,時間とともに何らかの不活性化にもかかわらず,信号の有意な強化につながりました (ε = 12).
結論:
- DNP NMRは,浄化なしでネイティブ環境での膜タンパク質の構造研究のための有効な方法です.
- この研究は,ネイティブの膜パッチ内のタンパク質-リガンド相互作用を調査する可能性を実証しています.
- これらの発見により,埋め込まれたタンパク質のさらなるDNP NMR調査が容易になります.
関連する概念動画
Cholinergic Receptors: Nicotinic
Nicotinic receptors are ligand-gated ion channels that are activated by acetylcholine and nicotine. Upon activation, they cause a rapid increase in the permeability of cells to K+, Na+, and Ca2+, followed by depolarization and excitation. They are in the autonomic ganglia, skeletal neuromuscular junction, CNS, and adrenal medulla.
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
Botulism
Botulism is a life-threatening neuroparalytic condition caused by botulinum neurotoxin, which is produced by the bacterium Clostridium botulinum, a Gram-positive, spore-forming, obligate anaerobe.In adults, the toxin enters the body in different ways: in foodborne botulism, the preformed toxin is absorbed in the intestine. In wound botulism, spores grow in injured tissue and release the toxin into the blood. Infant botulism differs mechanistically from adult forms. In infants, botulism commonly...
Cholinergic Neurons: Neurotransmission
Cholinergic neurotransmission involves the synthesis and the release of acetylcholine (ACh) in order to transmit nerve impulses across the synapse. The process begins with the synthesis of acetyl CoA, a precursor for ACh, from ATP, acetate, and coenzyme A in the mitochondria. Choline, another vital precursor, is transported inside the neuron through choline transporters, including high-affinity choline transporter CHT1, low-affinity choline transporter CTL1, and lower-affinity choline...
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Indirect-acting cholinergic agonists are agents that interact with the acetylcholinesterase enzyme in the synaptic cleft, preventing the breakdown of acetylcholine into choline and acetate. Consequently, the concentration of acetylcholine in the synaptic cleft increases. These agonists can be classified into reversible and irreversible inhibitors based on their duration of action.
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Neuromuscular Junction And Blockade
The site of chemical communication between a motor neuron and a muscle fiber is called the neuromuscular junction (NMJ). The end of the motor neuron at the NMJ divides into a cluster of synaptic end bulbs. The cytoplasm of these bulbs consists of synaptic vesicles enclosing acetylcholine molecules, the principal neurotransmitter released at the NMJ. The region opposite the synaptic bulb that ends in the muscle fiber is called the motor end plate, which has acetylcholine receptors. Within the...

