相关实验视频
Updated: Jul 12, 2026
19:56
Introduction to Solid Supported Membrane Based Electrophysiology
Published on: May 11, 2013
通过ClC Cl-通道的一种 prokaryotic 同类物介导的二次活性运输
Alessio Accardi1, Christopher Miller
1Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA.
Nature
|February 27, 2004
概括
细菌的ClC-ec1蛋白,以前被认为是一个离子通道,实际上是一个质子转运器. 这一发现表明,类似的分子结构可以执行不同的运输功能,模糊了通道和传送器之间的界限.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 结构生物学 结构生物学
背景情况:
- 化物 (ClC) 通道是真核生物中广泛存在的蛋白质家族,对肌肉刺激性和内体酸性化等细胞功能至关重要.
- 在 prokaryotes 中,ClC 功能在很大程度上是未知的,在 Escherichia coli 中的 ClC-ec1 被确定为可能通过挤出质子参与抗酸性.
研究的目的:
- 为了研究来自大肠杆菌的 prokaryotic ClC-ec1 蛋白质的精确功能.
- 为了确定ClC-ec1的高分辨率结构是否为其传输机制提供了洞察力.
- 重新评估CLC道和传送器之间的结构区别.
主要方法:
- 利用高分辨率的X射线晶体学来确定ClC-ec1.ec的结构.
- 进行了功能性测试,以阐明ClC-ec1.ec的传输机制.
- 将ClC-ec1的结构和功能与已知的真核细胞ClC通道进行比较.
主要成果:
- 该研究表明,ClC-ec1作为质子-化物 (H+-Cl-) 交换载体,而不是离子通道.
- ClC-ec1的分子架构保持不变,但支持与以前假设的 prokaryotic ClC 蛋白质不同的运输机制.
- 这一发现挑战了CLC道和传送器之间的既定结构二分法.
结论:
- 来自大肠杆菌的ClC-ec1蛋白作为H+-Cl-载体,有助于细菌的抗酸性.
- ClC 蛋白质的保存结构框架可以容纳从根本上不同的运输方式 (通道与传送器).
- 离子通道和输送器之间的结构界限不如以前假设的那样明确,需要重新评估ClC家族的功能多样性.
相关概念视频
01:47Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
01:55Secondary Active Transport
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...
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
01:32Secondary Active Transport
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...
01:32Secondary Active Transport
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...
01:14Active Transport
Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition.
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...