相关实验视频
Updated: Jun 16, 2025

11:45
Quantifying Agonist Activity at G Protein-coupled Receptors
Published on: December 26, 2011
19.2K
pKaGPCRs的计算:理解受体激活中的质突状态
Carlos A V Barreto1,2, João N M Vitorino3, Pedro B P S Reis3
1PhD Programme in Experimental Biology and Biomedicine, Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Casa Costa Alemão, 3030-789 Coimbra, Portugal.
Journal of chemical information and modeling
|August 16, 2024
概括
一个关键残留物的质子化,酸2.50,对于激活一些G蛋白结合受体 (GPCRs) 至关重要. 这种与质子结合的激活机制似乎是特定于某些GPCRs,如A2AR和B2AR.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 计算化学计算化学
背景情况:
- G蛋白结合受体 (GPCRs) 是关键的跨膜受体,参与许多细胞过程.
- 了解GPCR激活机制对于药物发现至关重要,但质子化-构造合的作用仍然不清楚.
- 保存的酸2.50残留物与GPCR功能有关,但其激活期间的质子化动态需要详细调查.
研究的目的:
- 在不同的A类GPCR中研究保存的酸2.50残留物的质子化行为.
- 确定酸2.50质子化在非活性和活性GPCR构造之间的过渡中的作用.
- 评估质子构成合是否是各种GPCR中保存的机制.
主要方法:
- 使用线性响应近似 (LRA) pKa计算协议.
- 分析了五种不同的A类GPCR,检查了活跃和不活跃的结构状态.
- 专注于高度保存的酸2.50残留物的质子化状态.
主要成果:
- 在腺氨酸A2A受体 (A2AR) 和Beta-2上腺素受体 (B2AR) 中,在非活性和活性状态之间观察到1.3 pKa单位的持续差异.
- 这种pKa转移表明在A2AR和B2AR的激活过程中,酸2.50的质子化.
- 对于大麻素受体1 (CB1R),神经素受体1 (NT1R) 和生长激素分泌受体 (GHSR) 的2.50 pKa值没有发现显著差异,这表明一种非保存的机制.
结论:
- 酸2.50的质子化是激活特定GPCRs的关键事件,例如A2AR和B2AR.
- 观察到的质子化形态合机制在所有研究的A类GPCR中并不普遍保持.
- 这些发现为GPCR激活背后的分子机制提供了关键的见解,并突出了受体特异性的差异.
相关概念视频
Activation and Inactivation of G Proteins
6.9K
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...
6.9K
G-protein Coupled Receptors
117.3K
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.
117.3K
GPCRs Regulate Adenylyl Cylase Activity
5.4K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
5.4K
GPCR Desensitization
5.9K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
5.9K
G Protein-coupled Receptors
11.6K
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...
11.6K
Transducer Mechanism: G Protein–Coupled Receptors
1.9K
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,...
GPCRs are also called heptahelical,...
1.9K

