对离子吸收和选择性的分子洞察力在CLCF化物/质子反载体中
Akihiro Y Nakamura1,2, Takuya Mabuchi2
1Graduate School of Engineering, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan.
The journal of physical chemistry. B
|April 15, 2025
概括
在CLCF的F-/H+反载体中,谷氨酸残留物E118和E318的质子化状态促进了离子的吸收. 特定的质子状态通过阻碍化物运输来增强化物选择性.
科学领域:
- 生物化学和分子生物物理学
- 膜运输蛋白质 膜运输蛋白质
- 离子通道和输送器
背景情况:
- CLCF F-/H+ 抗载体在细胞离子恒温中起着至关重要的作用.
- 了解离子吸收和选择性的机制对于生物和医学应用至关重要.
- 关键的谷氨酸残留物的质子化状态被假定会影响传送器功能.
研究的目的:
- 调查谷氨酸E118 (Gluex) 和E318 (Gluin) 质子化状态对离子吸收和选择性的影响.
- 为了阐明由CLCF反载体所导致的化物运输和化物排除的分子机制.
- 调和现有的化物运输模型,特别是原始和修改的风车机制.
主要方法:
- 用分子动力学模拟来建模CLCF F-/H+反载体.
- 进行了毛孔大小分析和潜在的平均力 (PMF) 计算.
- 在不同的条件下分析了符合性变化和残留物相互作用.
主要成果:
- 化物吸收在去质子化E118和质子化E318状态下得到促进,与原来的风车机制一致.
- 在这种状态下,孔径的增加减少了化物运输的能量屏障.
- 由化物诱导的螺旋到线圈过渡涉及74-87残留物,阻碍了化物运输并增强了化物选择性.
结论:
- E118_E318p状态通过调节孔隙动态和相互作用,显著提高离子选择性.
- 这些发现支持了特定的谷氨酸质子化状态在已建立的风车机制中的作用.
- 通过整合原始和修改风车路径的各个方面,可以实现统一的化物选择性吸收机制.
相关概念视频
01:44The Significance of Membrane Transport
20.3K
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
20.3K
01:16Facilitated Diffusion
253
The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane.
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
253
01:32Secondary Active Transport
6.6K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
6.6K
01:23Transcellular Transport of Solutes
3.3K
Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...
3.3K
01:17Pore Transport and Ion-Pair Transport
303
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
303
01:06Carrier-Mediated Transport
217
Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
217