The effect of 2,4-dinitrophenol on the properties of thin phospholipid films

Lea, E.J.A.; Croghan, P. C.

doi:10.1007/bf01869783

Cited by 64 publications

(45 citation statements)

References 15 publications

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“…The most obvious explanation for the observed dependence of conductance on concentration is that the exponent represents the number of monomers interacting to form a conducting unit, as has been suggested for the polyene antibiotics (Finkelstein & Cass, 1968), gramicidin A (Veatch et aZ., 1975) and many other carrier-type antibiotics. Such an explanation, attractive as it might seem, needs to be regarded cautiously in the light of the fact that co-operative (Cass et al, 1970) and other effects (Lea & Croghan, 1969;McLaughlin, 1972) between conducting units or subunits may influence their interpretation. Until detailed studies have been made of random fluctuations of current under voltage clamp, these suggestions remain speculative.…”

Section: Requirements Of Metal Salts For Cda Activitymentioning

confidence: 99%

A New Channel-forming Antibiotic from Streptomyces coelicolor A3(2) Which Requires Calcium for its Activity

Lakey¹,

Lea²,

Rudd³

et al. 1983

Microbiology

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A recently discovered antibiotic (CDA ; calcium-dependent antibiotic) of Streptomyces coelicolor A3(2) was found to be effective against a wide range of Gram-positive bacteria only in the presence of calcium ions. Producer and non-producer strains were identified and several media tested for their ability to support antibiotic production. The action of calcium was not simulated by any of the other cations tested. The antibiotic was found to induce discrete conductance fluctuations in planar lipid bilayer consistent with a channel-forming action. The electrical potential difference caused by a concentration difference of various salts across the CDAcontaining bilayer, showed the channel to be cation-selective but of a size that discriminated against tetramethyl ammonium and choline ions. The data indicate that the antibiotic activity of CDA is due to its action as a calcium-dependent ionophore.

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Section: Requirements Of Metal Salts For Cda Activitymentioning

confidence: 99%

A New Channel-forming Antibiotic from Streptomyces coelicolor A3(2) Which Requires Calcium for its Activity

Lakey¹,

Lea²,

Rudd³

et al. 1983

Microbiology

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“…There is little doubt that uncouplers, such as DNP, do increase the permeability of artificial lipid membranes; but this appears to be due to a rise in proton conductance, in contrast to the action of valinomycin which increases GK (Bielawsky, Thompson & Lehninger, 1966;Hopfer, Lehninger & Thompson, 1968;Liberman & Topaly, 1968;Lea & Croghan, 1969). It is therefore not clear that McLaughlin's (1972) observation that DNP increases K movements through a neutral phospholipid membrane exposed to a nonactin-K complex is strictly relevant in this context.…”

Section: Nature Of Conductance Changementioning

confidence: 99%

Significance of 2,4‐dinitrophenol action on spinal motoneurones.

Krnjević¹,

Puil²,

Werman³

1978

The Journal of Physiology

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SUMMARY1. Extracellular iontophoretic applications of DNP lead to an increase in the membrane conductance of cat spinal motoneurones, manifested by a rise in input conductance, a slower rate of rise and fall of action potentials, and occlusion of the afterhyperpolarization.2. There is also some hyperpolarization, but the reversal potential for the action of DNP is only about 12 mV more negative than the resting potential.3. These effects of DNP can be abolished or significantly reduced by intracellular injections of EGTA. On the other hand, DNP can partly reverse the decreased conductance and the depression of the slow afterhyperpolarization caused by EGTA.4. Intracellular injections of DNP also induce a rise in input conductance; when repeated, they tend to have a depolarizing effect, mainly irreversible.5. It is concluded that DNP acts principally inside the motoneurone, by liberating bound internal Ca, the free Ca ions then raising membrane conductance, especially GK.

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“…3c). This delay may reflect the slow intracellular accumulation of permeant species of DNP (HA2 _1; A-1 is dinitrophenate), the concentration of which is much lower than that of the A -or HA form (LEA and CROGHAN, 1969;Fig. 7 (SORIMACHI and YAMAGAMI, 1982) suggest that these compounds activate the Ca entry pathway, although the direct evidence for the increased entry of Ca is lacking.…”

Section: Discussionmentioning

confidence: 99%

The secretory mechanism in adrenal chromaffin cells by nitrophenol compounds: Possible involvement of the change in the surface potentials.

Yamagami

Sorimachi

1987

Jpn.J.Physiol

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The rabbit adrenal gland was perfused with a modified Locke's medium and the mechanism of adrenaline secretion induced by nitrophenol compound was investigated. The secretory response to 2,4-dinitrophenol (DNP) or trinitrophenol (TNP) showed the following peculiar features. (1) Prolonged exposure to DNP or TNP caused an immediate, and long-lasting increase of secretion only in the presence of Ca. (2) The response to DNP depended on the concentration of Ca, but that to TNP was largest in the presence of 0.5 mM Ca. (3) Re-addition of 2 mM Ca during prolonged exposure to DNP or TNP produced a larger response than did the simultaneous addition of Ca and either DNP or TNP. (4) The response to DNP in the presence of 2 mM Ca was markedly reduced by removal of external Na, but the Na dependency became less marked in the presence of 0.1 mM Ca. The response to TNP in the presence of 0.5 mM Ca was slightly reduced in the absence of Na. (5) DNP or TNP caused a much larger response during depolarization with a high K, Rb, or Cs medium than that with a 5 mM KCl medium. (6) The response to DNP was largely potentiated in the absence of most ions in the presence of only 0.1 mM Ca and that to TNP was potentiated in the presence of only 0.5 mM Ca under the same condition. (7) Re-addition of Ca 5 min after the removal of DNP or TNP still caused substantial secretion. These results suggest that nitrophenol compounds stimulate secretion by two independent mechanisms: one is related to its effect on the surface potentials of the plasma membrane and the other unknown except for the possible dependence of Na and Ca.

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The effect of 2,4-dinitrophenol on the properties of thin phospholipid films

Cited by 64 publications

References 15 publications

A New Channel-forming Antibiotic from Streptomyces coelicolor A3(2) Which Requires Calcium for its Activity

A New Channel-forming Antibiotic from Streptomyces coelicolor A3(2) Which Requires Calcium for its Activity

Significance of 2,4‐dinitrophenol action on spinal motoneurones.

The secretory mechanism in adrenal chromaffin cells by nitrophenol compounds: Possible involvement of the change in the surface potentials.

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