Gタンパク質結合受容体のアゴニスト選択経路におけるコンフォームトランジションの計算マッピング
Supriyo Bhattacharya1, Nagarajan Vaidehi
1Division of Immunology, Beckman Research Institute of the City of Hope, 1500, East Duarte Road, Duarte, California 91010, USA.
Journal of the American Chemical Society
|March 19, 2010
まとめ
Gタンパク質結合受容体 (GPCR) の活性化経路を理解することは,薬剤設計の鍵です. コンピューティング・メソッドは,リガンドの有効性が受容体構成と活性化にどのように影響するかを明らかにし,機能的に特定の薬物開発の洞察を提供します.
科学分野:
- 計算式生体物理学について
- 構造生物学 構造生物学とは
- 薬理学 薬理学とは
背景:
- Gタンパク質結合受容体 (GPCR) は,重要な薬物標的である.
- リガンドの化学構造と有効性は,GPCRsの活性状態構成を決定する.
- 活性化経路を理解することは,機能的に特定のGPCR薬の設計に不可欠です.
研究 の 目的:
- 異なるリガンドの有効性がβ2-アドレナリン受容体の潜在的なエネルギー環境をどのように調節するかを調査する.
- 様々なアゴニストおよび部分アゴニストに対するGPCRsの活性化経路を計算的に導き,分析する.
- GPCRの活性化における水素結合や水分極化などの特定の分子相互作用の役割を調査する.
主な方法:
- ベータ2-アドレナリゲン受容体の結晶構造から始まり,粗い粒子の計算方法を使用しました.
- 受容体トランスメブランヘリクスの体系的なコンフォーマーションスランニングを行い,その後,エネルギー最小化とリガンドリドッキングを行いました.
- 活性化経路を導出するためにモンテカルロアルゴリズムを使用し,光スペクトロスコピーの測定に対して検証しました.
主要な成果:
- 完全および部分アゴニストの誘導活性化経路は,実験データと一致する.
- アゴニストの完全活性化における主要なイベントを特定した: エネルギーの下降ステップ,中間形成,ヘリックス5-ヘリックス6の水素結合の断絶を含むバリアの横断.
- ステリック阻害により,フルアゴニスト (ノレアピネフリン) から部分アゴニスト (サルブタモール) の活性化経路が区別され,仮想スクリーニングでノンカテコールアゴニストの濃縮が実証されました.
結論:
- 粗粒度計算方法は,GPCRの活性化経路とリガンド特異の構成変化を効果的にモデル化することができます.
- 水分極化と螺旋間水素結合のダイナミクスは,GPCR活性化バリアの横断に不可欠です.
- 開発された計算アプローチは,実験仮説を生成し,GPCRの活性化メカニズムを理解するための強力なツールを提供します.
関連する概念動画
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...


