Selective artificial transmembrane channels for protons by formation of water wires

Wen Si1, Lei Chen, Xiao-Bo Hu

  • 1Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China.

Related Concept Videos

Aquaporins01:25

Aquaporins

Aquaporins or AQPs are a family of integral membrane proteins whose primary function is to transport water, while some called aquaglyceroporins also transport glycerol. In addition, aquaporins have also been suspected to be involved in transporting volatile substances, such as carbon dioxide and ammonia, across membranes. Such AQPs that act as gas channels are often highly expressed in cells involved in the gaseous exchange, such as red blood cells, epithelial cells, and pulmonary capillaries.
Potentiometry: Membrane Electrodes01:15

Potentiometry: Membrane Electrodes

Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
Ion Channels01:19

Ion Channels

The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange.
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
The Significance of Membrane Transport01:44

The Significance of Membrane Transport

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...
Electrochemical Gradient and Channel Proteins: An Overview01:21

Electrochemical Gradient and Channel Proteins: An Overview

An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell.  This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
Voltage-gated Ion Channels01:26

Voltage-gated Ion Channels

Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...