proton pump

(redirected from Proton channel)

pump

 [pump]
1. an apparatus for drawing or forcing liquid or gas.
2. to draw or force liquids or gases.
blood pump a machine used to propel blood through the tubing of extracorporeal circulation devices.
breast pump a pump for taking milk from the breast.
calcium pump the mechanism of active transport of calcium (Ca2+) across a membrane, as of the sarcoplasmic reticulum of muscle cells, against a concentration gradient; the mechanism is driven by hydrolysis of ATP.
enteral feeding pump an infusion pump specifically designed for administration of a solution through a feeding tube.
insulin pump see insulin pump.
intra-aortic balloon pump see intra-aortic balloon pump.
muscle pump compression of veins by the contraction of skeletal muscles, forcing blood towards the heart against the flow of gravity; seen particularly in the deep veins of the lower limbs. Called also venous pump.
proton pump a system for transporting protons across cell membranes, often exchanging them for other positively charged ions.
sodium pump (sodium-potassium pump) the mechanism of active transport driven by the energy generated by Na+,K+-ATPase, by which sodium (Na+) is extruded from a cell and potassium (K+) is brought in, so as to maintain the low concentration of sodium and the high concentration of potassium within the cell with respect to the surrounding medium. A high concentration of intracellular potassium is necessary for vital processes such as protein biosynthesis, certain enzyme activities, and maintenance of the membrane potential of excitable cells. Called also Na+-K+ pump.
stomach pump see stomach pump.
venous pump muscle pump.

pro·ton pump

molecular mechanism for the net transport of protons across a membrane; usually involves the activity of an ATPase.

proton pump

An ATP-dependent H+ ion transporter present in the membranes of lysosomes and vacuoles, which maintains a low pH (4.5-5.0) inside these organelles. Proton pumping is also required in the electron transport chain, where an NADH (or FADH) is oxidised to NAD+ (or FAH+), releasing 2 electrons and a proton.

pro·ton pump

(prō'ton pŭmp)
Molecular mechanism for the net transport of protons across a membrane; usually involves the activity of adenosine triphosphatase.

proton pump

a specialized assembly of proteins in a cell membrane which transports protons against a concentration gradient.

proton

an elementary particle of mass number 1, with a positive charge equal to the negative charge of the electron; a constituent particle of every nucleus, the number of protons in the nucleus of each atom of a chemical element being indicated by its atomic number.

proton pump
see sodium pump.
proton pump inhibitor
a class of therapeutic agents which are used to counteract the effects of proton pumps in tissues and organs, particularly used in counteracting gastric hypersecretion and acidity.
References in periodicals archive ?
The study showed that these drugs block influenza A viruses from reproducing and spreading by attaching to a site within a proton channel necessary for the virus to infect healthy cells.
A paper based on X-ray studies concluded the drug attached to the lumen of the proton channel, the area inside the channel, and stopped the virus by blocking the channel.
Another study showed the drug attached to the surface of the virus protein near the proton channel and stopped the virus by indirectly changing the channel structure.
The new study led by Mei Hong showed that when amantadine is present at the pharmacologically relevant amount of one molecule per channel, it attaches to the lumen inside the proton channel.
Treatment of epidemic and pandemic influenza with neuraminidase and M2 proton channel inhibitors.
Using cooled RF coils and preamplifiers, Prodigy offers a sensitivity enhancement over conventional probes of a factor of 2x-3x for X-nuclei from 15N to 31P, and of 2x on the proton channel.
The sensitivity gain on the proton channel exceeds RT probe performance by a factor of 2x or more.
Second, fluorocarbon membranes have a soft, rubbery consistency, and in the presence of methanol, they tend to swell, making the proton channels even larger still.
PolyFuel's now-patented hydrocarbon membrane material self-assembles proton channels that are nano-engineered to be significantly smaller than those in fluorocarbon membranes.