The action of certain antibiotics on mitochondrial, erythrocyte and artificial phospholipid membranes. The role of induced proton permeability

Abstract

1. The action of the antibiotics enniatin A, valinomycin, the actin homologues, gramicidin, nigericin and dianemycin on mitochondria, erythrocytes and smectic mesophases of lecithin-dicetyl hydrogen phosphate was studied. 2. These antibiotics induced permeability to alkali-metal cations on all three membrane systems. 3. The ion specificity on each membrane system was the same. 4. Enniatin A, valinomycin and the actins did not induce permeability to protons, whereas nigericin and dianemycin rendered all three membrane systems freely permeable to protons. 5. Several differences were noted between permeability induced by nigericin and that induced by gramicidin. 6. The action of all these antibiotics on mitochondrial respiration could be accounted for by changes in passive ion permeability of the mitochondrial membrane similar to those induced in erythrocytes and phospholipid membranes, if it is assumed that a membrane potential is present in respiring mitochondria.The effects of valinomycin on mitochondrial respiration have been investigated extensively

Second febs—ferdinand springer lecture membrane active complexones. chemistry and biological function

“…Alkali ion transport across membranes by the enniatin ionophores has been studied much less extensively than that of valinomycin [24,[29][30][31][32]361.…”

The effect of light on the permeability of a myxomycete

“…4C). Nigericin appears, in mitochondria and erythrocytes, to promote a 1:1 H+-K + exchange [16,18] and at higher concentrations to effect a K +-dependent uncoupling under specific [K +] and substrate conditions [ 17]. The initial and very rapid response to nigericin (before GS) is a proton uptake (see fig.…”

Some factors affecting the valinomycin-induced leak from liposomes

“…Furthermore, the antibiotic drastically increases cationic exchange diffusion through non-energized membranes if complexable cations are present on both sides [8][9][10]. For reasons of electrogenic neutrality, however, the induced Abbreviation: FCCP.…”

“…carbonylcyanide p-trifluoromethoxyphenylhydrazone. fluxes normally are very limited if the complexable cation is present on only one side [8,.…”

“…In the latter case both valinomycin and an uncoupler are necessary to give a significant increase of the alkali ionic flux [8,[11][12][13]. Under these conditions the valinomycin-mediated alkali ionic flux is accompanied by an uncoupler-mediated transport of H + in the opposite direction, as reflected by changes in pH [8,12,14].…”