How does valinomycin transport K+ ions?
Valinomycin is highly selective for potassium ions over sodium ions within the cell membrane. It functions as a potassium-specific transporter and facilitates the movement of potassium ions through lipid membranes “down” the electrochemical potential gradient.
What type of transport is valinomycin?
Valinomycin can selectively transport alkali metal ions through biological and synthetic membranes. (6) This ion-transporting property is primarily due to the formation of a metal ion–peptide complex.
Is valinomycin active or passive transport?
active secondary transport
Valinomycin is an antibiotic which kills microbial cells by disrupting the essential role of ion gradients (by collapsing ion gradients across cellular membranes) in active secondary transport and energy conservation.
How does valinomycin affect mitochondrial electron transfer?
Valinomycin triggers rapid loss of mitochondrial membrane potential. This precedes cytoplasmic acidification, which leads to cysteine-active-site protease activation, DNA fragmentation and cell death.
Why valinomycin is selective to potassium ions?
Valinomycin is highly selective for potassium ions over sodium ions within the cell membrane. It functions as a potassium-specific transporter and facilitates the movement of potassium ions through lipid membranes “down” the electrochemical potential gradient.
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CHEBI:28545 – valinomycin.
| ChEBI Name | valinomycin |
|---|---|
| Download | Molfile XML SDF |
Why is valinomycin highly selective for K+ relative to Na+?
The reason valinomycin retains K+/Na+ selectivity is because this 4-fold geometry, in which all the 4 ligands are cluttered on one side of the Na+ ion (figure 4), is energetically less stable than the preferred 4-fold geometries in gas phase, such as the tetrahedral or planar18 geometries.
What is valinomycin used for?
Valinomycin is a potent antibiotic. It is commonly used as an agent to induce apoptosis and can also be used to calibrate potentiometric responses in membrane experiments involving potential-sensitive dyes such as di-4-ANEPPS.
Is valinomycin active transport?
Valinomycin is a naturally occurring dodecadepsipeptide used in the transport of potassium and as an antibiotic. Valinomycin is obtained from the cells of several Streptomyces species, S.
What is the function of valinomycin?
Valinomycin is a potent antibiotic. It is commonly used as an agent to induce apoptosis and can also be used to calibrate potentiometric responses in membrane experiments involving potential-sensitive dyes such as di-4-ANEPPS. For Research Use Only. Not for human or animal therapeutic or diagnostic use.
How does valinomycin affect ATP synthesis?
Valinomycin caused transient uncoupling of ATP synthesis driven by respiration since it strongly inhibited ATP synthesis during the initial 100 ms but had no effect during steady state phosphorylation.
Is Valinomycin active transport?
How does Valinomycin affect ATP synthesis?
Why can valinomycin transport ions?
What is valinomycin and what is its impact on the membrane potential?
Abstract. Valinomycin is a depsipeptide antibiotic which selectively translocates potassium across biologic membranes. This potassium ionophore was observed to inhibit phytohemagglutinin-stimulated blastogenesis and proliferation in human lymphocytes.
Is valinomycin an antibiotic?
Valinomycin is a depsipeptide antibiotic which selectively translocates potassium across biologic membranes. This potassium ionophore was observed to inhibit phytohemagglutinin-stimulated blastogenesis and proliferation in human lymphocytes.
How does valinomycin inhibit ATP synthesis?
The synthesis is specific for K+- valinomycin as replacement of K+ by Na+ causes a slight and relatively concentration-insensitive ATP synthesis. It is important that the ATP synthesis by valinomycin-treated chloroplasts is reduced to that provided by Na+-valinomycin by the addition of DNP to the K+-valinomycin.
Is Valinomycin an uncoupler?
Valinomycin in the presence of potassium is a potent uncoupler of corn (Zea mays L.) mitochondria, eliminating respiratory control. Valinomycin produces higher steady state potassium phosphate swelling which can be reversed to give active shrinkage if mersalyl is added to block the Pi−/OH− antiporter.
Is Valinomycin an uncoupler for oxidative phosphorylation?
1 and 2 and Table I on the effect of valinomycin in the absence of potassium support the contention of Moore and Pressman (3) t,hat valinomycin is not an effective uncoupler of oxidative phosphorylation in the absence of po- t’assium.
Does Valinomycin act as an uncoupler or an inhibitor of oxidative phosphorylation?
Valinomycin acts as an uncoupler. It combines K+ to form a complex that passes through the inner mitochondrial membrane, dissipating the membrane potential. ATP synthesis decreases, which causes the rate of electron transfer to increase.