151
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Panet R, Atlan H. Inhibitory effects of two potassium ionophores on ouabain-resistant potassium fluxes in reticulocyte cell membrane. FEBS Lett 1979; 103:172-5. [PMID: 467647 DOI: 10.1016/0014-5793(79)81275-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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152
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Njus D, Radda GK. A potassium ion diffusion potential causes adrenaline uptake in chromaffin-granule 'ghosts'. Biochem J 1979; 180:579-85. [PMID: 486135 PMCID: PMC1161097 DOI: 10.1042/bj1800579] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Membrane vesicles ('ghosts') formed from bovine chromaffin granules accumulate adrenaline in response to a diffusion potential produced by adding K+ in the presence of valinomycin. This uptake occurs as a short (2--5 min) burst because of the transient nature of the diffusion potential. The potential-driven uptake is optimal at pH approximately 7.2, is inhibited by reserpine, and has an initial rate comparable with that of ATP-driven uptake. These results show that ATP-dependent adrenaline uptake may occur at least partly in response to the membrane potential generated by an electrogenic proton-translocating adenosine triphosphatase found in chromaffin-granule membranes.
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153
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Panet R, Atlan H. Coupling between K efflux, ATP metabolism and protein synthesis in reticulocytes. Biochem Biophys Res Commun 1979; 88:619-26. [PMID: 465059 DOI: 10.1016/0006-291x(79)92093-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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154
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Beck JC, Rosen BP. Cation/proton antiport systems in escherichia coli: properties of the sodium/proton antiporter. Arch Biochem Biophys 1979; 194:208-14. [PMID: 36033 DOI: 10.1016/0003-9861(79)90611-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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155
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Terada H, Kubota S. Does hydrophobic isothiocyanate really uncouple oxidative phosphorylation in mitochondria? Uncoupling activity of a product of isothiocyanate in dimethylsulfoxide solution. FEBS Lett 1979; 100:37-40. [PMID: 437106 DOI: 10.1016/0014-5793(79)81126-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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156
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Satoh K, Katoh S. Two electrogenic mechanisms contributing to the 560 nm absorption changes in intact Bryopsis chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 545:454-65. [PMID: 427138 DOI: 10.1016/0005-2728(79)90154-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Light -induced absorbance changes at 560 nm in dark-adapted intact chloroplasts of the green alga, Bryopsis maxima were studied in the time range of 200 ms. The initial rise of the 560 nm signals consists of two major components which are both electrochromic absorbance changes of the carotenoids, siponein and/or siphonaxanthin, but different in mechanisms of the field formation. The first component (component S) is related to electron transport since it was sensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) and showed at light-intensity dependence similar to that of electron transport in chloroplasts. In the presence of DCMU, component S could be restored on addition of proton-transporting electron donors such as reduced 2.6-dichlorophenol indophenol and phenazine methosulfate, but not on addition of N,N,N',N'-tetramethyl-p-phenylenediamine which does not carry protons with electrons (Trebst, A. (1974) Annu. Rev. Plant Physiol. 25, 423--458). We propose that component S is due to the electric field set up by the proton translocation across the thylakoid membrane. The second component (component R) was resistant to DCMU and DBMIB. The light-intensity dependency of component R was similar to that of cytochrome f photooxidation which showed saturation at a relatively low light intensity. The magnitude of component R was markedly reduced by phenylmercuric acetate, suggesting the participation of ferredoxin and ferredoxin-NADP oxidoreductase in the mechanism of the field formation responsible for this component. In the presence of DCMU and phenylmercuric acetate, time courses of the 560 nm changes paralleled those of cytochrome f changes. These results indicate that component R is due to the electric field formed between oxidized cytochrome f and other intersystem electron carriers located in the inner part of the thylakoid membrane and reduced electron acceptors of Photosystem I situated on the membrane surface. The complex natures of the 560 nm changes, as well as the contributions of Photosystems I and II to the absorbance changes, are explained in terms of the two electrogenic mechanisms.
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157
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Crowther D, Mills JD, Hind G. Protonmotive cyclic electron flow around photosystem I in intact chloroplasts. FEBS Lett 1979; 98:386-90. [PMID: 421911 DOI: 10.1016/0014-5793(79)80223-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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158
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Garty H, Eisenbach M, Shuldman R, Caplan SR. Light-induced pH changes in sub-bacterial particles of Halobacterium halobium. Effects of ionophores. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 545:365-75. [PMID: 83878 DOI: 10.1016/0005-2728(79)90213-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The kinetics of light-induced acidification and of the subsequent dark-induced alkalization in suspensions of sub-bacterial particles of Halobacterium halobium may be expressed as the sum of two exponentials, indicating two processes (Eisenbach, M., Bakker, E.P., Korenstein, R. and Caplan, S.R. (1976) FEBS Lett. 71, 228--232). We studied the effects of carbonyl cyanide p-trifluoromethyoxy phenyl-hydrazone, nigericin, gramicidin D, valinomycin, and monactin on the extents and the rate constants of the two processes. The various ionophores affected the two processes differently and in general the slower process was more sensitive to their presence. Valinomycin and monactin had relatively minor effects, apparently due to the high ionic strength of the suspension. When an artificial membrane potential was created in the dark, the light-induced acidification was preceded by a transient alkalization as is usually observed in intact cells. These results are discussed in the light of a suggested model accounting for the two processes (Caplan, S.R., Eisenbach, M., Cooper, S., Garty, H., Klemperer, G. and Bakker, E.P. (1977) in Bioenergetics of Membranes (Packer, L., Papageorgiou, G.C. and Trebst, A., eds.), pp. 101--114, Elsevier/North-Holland Biomedical Press, Amsterdam), taking into account the different selectivities of the ionophores applied.
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159
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160
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Lakshminarayanaiah N. Transport processes in membranes: a consideration of membrane potential across thick and thin membranes. Subcell Biochem 1979; 6:401-94. [PMID: 377586 DOI: 10.1007/978-1-4615-7945-8_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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161
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Cockrell RS, Pressman BC. The use of K+ concentration gradients for the synthesis of ATP by mitochondria. Methods Enzymol 1979; 55:666-75. [PMID: 37406 DOI: 10.1016/0076-6879(79)55074-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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162
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Sulakhe SJ, Sulakhe PV. Interactions of ionophores (A23187 and X-537A) with sarcolemma and sarcoplasmic reticulum. GENERAL PHARMACOLOGY 1979; 10:103-13. [PMID: 35444 DOI: 10.1016/0306-3623(79)90044-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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163
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164
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Busse D. Transport of L-arginine in brush border vesicles derived from rabbit kidney cortex. Arch Biochem Biophys 1978; 191:551-60. [PMID: 742890 DOI: 10.1016/0003-9861(78)90393-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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165
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Crompton M, Heid I. The cycling of calcium, sodium, and protons across the inner membrane of cardiac mitochondria. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 91:599-608. [PMID: 32035 DOI: 10.1111/j.1432-1033.1978.tb12713.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A method is described that permits simultaneous determination of the net charge transfer associated with Ca2+ transport by the ruthenium-red-sensitive carrier and the ionized internal [Ca2+] in heart mitochondria. The data indicate that this carrier catalyses a charge-uncompensated flux of Ca2+. Full charge compensation for Ca2+ influx is provided by the respiration-dependent efflux of H+. The net efflux of Ca2+ induced by Na+ is analysed in terms of two other carriers, a Na+-Ca2+ antiporter and a Na+-H+ antiporter. Evidence is presented that these two carriers are separate and that the Na+-H+ exchange is the more rapid. The fluxes of Ca2+, Na+ and H+ during the Na+-induced efflux of Ca2+ support a series of events in which the Na+-H+ exchange enables unidirectional Ca2+ fluxes via the uniport and antiport systems to be integrated into a cycle.
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166
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Terada H, Uda M, Kametani F, Kubota S. Structural requirements of alkyl acyldithiocarbazates for the uncoupling of oxidative phosphorylation in mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 504:237-47. [PMID: 718875 DOI: 10.1016/0005-2728(78)90172-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A structure-activity relationship study on the uncoupling of alkyl acyldithiocarbazates was carried out. Greater activity was observed with increasing alkyl chain length, the optimum being C9. A further increase in alkyl chain length caused a decrease in the activity. Thione-thiol tautomeric forms with a dissociable proton were dound to be of primary importance for the uncoupling and the role of the acyl group was auxiliary. The reactivity of the SH group of alkyl acyldithiocarbazates with an SH-reagent was very low. These compounds facilitated the valinomycin-induced swelling of non-respiring mitochondria and non-sonicated lecithin liposomes in isotonic potassium acetate solution.
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167
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Boehler BA, De Gier J, Van Deenen LL. The effect of gramicidin A on the temperature dependence of water permeation through liposomal membranes prepared from phosphatidylcholines with different chains lengths. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 512:480-8. [PMID: 81688 DOI: 10.1016/0005-2736(78)90158-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The permeation of water through liposomal membranes composed of various saturated phosphatidylcholine plus gramicidin A was studied as a function of temperature. 1. The presence of gramicidin in the liposomal bilayers caused an increase in water permeability. Below the phase transition temperature this effect could be measured quite clearly in all the systems we tested, but the extent of the increase was largely dependent on the length of the hydrocarbon chains. 2. Increasing amounts of gramicidin caused a gradual disappearance of the abrupt change in the rate of water permeation near the gel-liquid crystalline phase transition temperature of dipalmitoyl phosphatidylcholine liposomes. Differential scanning calorimetry analysis of the system containing these relatively small amounts of gramicidin still showed a clear transition from the liquid crystalline to the gel state with only a slight reduction in the enthalpy change. 3. In liposomes composed of dimyristoyl, dipalmitoyl and saturated egg phosphatidylcholine there was a concomitant decrease in the activation energy of water permeation in the presence of gramicidin below and above the phase transition temperature. The activation energy for water permeation through longer chained distearoyl phosphatidylcholine liposomal bilayers was the same with or without gramicidin in the bilayer. 4. It is concluded that the ability of gramicidin to form conducting channels in a gel state bilayer depends on the thickness of the paraffin core.
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168
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Lücke H, Stange G, Kinne R, Murer H. Taurocholate--sodium co-transport by brush-border membrane vesicles isolated from rat ileum. Biochem J 1978; 174:951-8. [PMID: 581553 PMCID: PMC1186000 DOI: 10.1042/bj1740951] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Uptake of taurocholate into brush-border membrane vesicles isolated from rat small intestine by a Ca(2+) -precipitation method was investigated by using a rapid-filtration technique. Uptake of taurocholate by ileal brush-border membranes consisted of three phenomena: binding to the outside of the vesicles, transfer across the vesicle membrane and binding to the intravesicular compartment. The transport of taurocholate across the brush-border membranes was stimulated in the presence of Na(+) compared with the presence of K(+); stimulation was about 11-fold in the presence of a NaCl gradient (Na(o)>Na(i)), where the subscripts refer to ;outside' and ;inside' respectively, and 4-fold under equilibrium conditions for Na(+) (Na(o)=Na(i)). In the presence of a Na(+) gradient a typical ;overshoot' phenomenon was observed. Membranes preloaded with unlabelled taurocholate showed an accelerated entry of labelled taurocholate (tracer exchange) in the presence of Na(+) compared with the presence of K(+). The stimulation by Na(+) was observed only in membrane preparations from the ileum. Addition of monactin, an ionophore for univalent cations, decreased the Na(+)-gradient-driven taurocholate uptake. The Na(+)-dependent taurocholate transport showed saturation kinetics and the phenomenon of counterflow and was inhibited by glycocholate. Other cations such as Li(+), Rb(+) and Cs(+) could not replace Na(+) in its stimulatory action. When the electrical potential difference across the vesicle membrane was altered by establishing different diffusion potentials (anion replacement; K(+) gradient+/-valinomycin) a more-negative potential inside stimulated Na(+)-dependent taurocholate transport. These data demonstrate the presence of a rheogenic (potential sensitive) Na(+)-taurocholate co-transport system in ileal brush-border membranes and support the hypothesis that the reabsorption of bile acids in the ileum is a secondary active uptake.
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169
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Louis CF, Fudyma G, Nash-Adler P, Shigekawa M, Katz AM. Effects of monovalent cation ionophores on calcium uptake by rabbit skeletal muscle sarcoplasmic reticulum vesicles. FEBS Lett 1978; 93:61-4. [PMID: 81144 DOI: 10.1016/0014-5793(78)80805-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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170
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Brierley GP, Jurkowitz M, Jung DW. Osmotic swelling of heart mitochondria in acetate and chloride salts. Evidence for two pathways for cation uptake. Arch Biochem Biophys 1978; 190:181-92. [PMID: 101147 DOI: 10.1016/0003-9861(78)90266-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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171
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Kawai K, Akita T, Nozawa Y. Biochemical studies of pigments from a pathogenic fungus Microsporum cookei. V. Evidence for the transmembrane permeability of xanthomegnin across phospholipid bilayer membranes. EXPERIENTIA 1978; 34:977-8. [PMID: 212291 DOI: 10.1007/bf01915296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Direct evidence is provided for the transmembrane permeation of xanthomegnin across phospholipid bilayer membranes using ascorbate-loaded liposomes. This process may be associated with an uncoupling effect on the oxidative phosphorylation of mitochondria.
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172
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Chen ST, Springer CS. Interaction of antibiotic lasalocid A (X537A) with praseodymium(III) in methanol. BIOINORGANIC CHEMISTRY 1978; 9:101-22. [PMID: 698278 DOI: 10.1016/s0006-3061(00)80284-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The binding of lasalocid A (X537A) to Pr(III) in methanol has been studied by lasalocid fluorescence, circular dichroism, and 1H and 13C NMR spectroscopy. It is clear that in addition to a mono complex, bis and tris complexes are also formed. Values of the binding constants and spectral properties of the various complexes have been determined by computer fitting of the binding isotherms. The Pr (III) ion binds only at the salicylic "head" of the lasalocid A, in stark contrast with other known structures. The lasalocid A appears to have an "open" conformation in these complexes. The relevance of these results to the structure and conformation of the Ca(II) complex is discussed. The first order rate constant for the dissociation of the tris complex has also been determined.
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173
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Sunamoto J, Kondo H, Yoshimatsu A. Liposomal membrane. I. Chemical damage of liposomal membranes with functional detergent. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 510:52-62. [PMID: 667037 DOI: 10.1016/0005-2736(78)90129-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The interaction and reaction between liposomal membrane and a functional detergent, N-hexadecyl-N-(imidazol-4-yl)methyl-N,N-dimethylammonium chloride hydroperchlorate (Im-I), have been investigated in conjunction with the leakage of bromothymol blue encapsulated as a marker in the bilayers of liposomes. Im-I carries an imidazole moiety and was expected to behave as a simple lipase model. The reaction with Im-I significantly enhanced the leakage of bromothymol blue encapsulated in the egg lecithin and dipalmitoyl phosphatidylcholine liposomes. During the course of reaction with Im-I, the formation of acyl-imidazole intermediate was clearly identified, which was certainly connected with the bromothymol blue release. From various kinetic results on bromothymol blue release and acyl-imidazole formation, it has been suggested that the bromothymol blue release from liposomal bilayer may be caused by the local and instantaneous decomposition of lipids when Im-I penetrates into the bilayer. However, it has also been demonstrated that the immediate reconstruction of liposomes retains the barrier function to protect against the further release of bromothymol blue.
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174
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Solie TN, Yuncker C. Adriamycin induced changes in translocation of sodium ions in transporting epithelial cells. Life Sci 1978; 22:1907-19. [PMID: 307643 DOI: 10.1016/0024-3205(78)90478-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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175
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Hammerman M, Sacktor B. Transport of beta-alanine in renal brush border membrane vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 509:338-47. [PMID: 77680 DOI: 10.1016/0005-2736(78)90052-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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176
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Hoogerheide JG, Popov AI. Study of monensin complexes with monovalent metal lons in anhydrous methanol solutions. J SOLUTION CHEM 1978. [DOI: 10.1007/bf00662896] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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177
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Nishino H, Schiller RM, Parnes JR, Isselbacher KJ. Role of Na+ in alpha-aminoisobutyric acid uptake by membrane vesicles from mouse fibroblasts transformed by simian virus 40. Proc Natl Acad Sci U S A 1978; 75:2329-32. [PMID: 79182 PMCID: PMC392546 DOI: 10.1073/pnas.75.5.2329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The uptake of alpha-amino[(3)H]isobutyric acid (AIB) was studied in membrane vesicles from mouse fibroblasts transformed by simian virus 40 to examine the features of the Na(+)-stimulated and Na(+)-dependent AIB transport process. The simultaneous addition of NaCl and AIB to these vesicles produced a transient accumulation, or "overshoot," of amino acid 3-4 times the equilibrium value. Both the initial rate of uptake and the rate of fall of intravesicular AIB after maximal accumulation were sensitive to the temperature of incubation. The overshoot of AIB uptake was enhanced with Na(+) salts of highly permeant lipophilic anions, such as SCN(-) and NO(3) (-), and was decreased by the addition of SO(4) (2-), a relatively impermeant ion. Gramicidin D, which enhances the membrane conductance of Na(+) electrogenically, decreased the overshoot, while a potassium diffusion potential, induced by valinomycin (in K(+)-preloaded membrane vesicles), produced a Na(+)-dependent overshoot of AIB uptake. When vesicles were preincubated with both Na(+) and AIB, followed by the generation of an interior negative membrane potential (by the addition of SCN(-)), an overshoot of AIB uptake resulted. However, this did not occur in the absence of Na(+). It is concluded that, apart from its role in the generation of a transmembrane electrochemical potential, Na(+) is essential for the overshoot of AIB uptake.
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178
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Webster KA, Bronk JR. Ion movements during energy-linked mitochondrial structural changes. J Bioenerg Biomembr 1978; 10:23-44. [PMID: 45333 DOI: 10.1007/bf00743225] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The structure of isolated rat liver mitochondria has been observed in the electron microscope following incubation of the mitochondria in vitro under a variety of conditions. The results show that ultrastructural changes are only associated with the energization and deenergization of isolated mitochondria if the composition of the incubation medium permits ion movements in or out of the matrix. The mechanism of energy coupling does not appear to depend on these major mitochondrial structural changes. The addition of low levels of valinomycin greatly increases the rate at which the matrix compartment swells and shrinks on energization and deenergization even at low K+ concentrations.
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179
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Tyrakowski T, Milutinović S, Schulz I. Studies on isolated subcellular components of cat pancreas. III. Alanine-sodium cotransport in isolated plasma membrane vesicles. J Membr Biol 1978; 38:333-46. [PMID: 633354 DOI: 10.1007/bf01870150] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transport of alanine was studied in isolated plasma membrane vesicles from cat pancreas using a rapid filtration technique. The uptake is osmotically sensitive and the kinetics of L-alanine transport are biphasic showing a saturable and a nonsaturable component. The saturable component is seen only when a sodium gradient directed from the medium to the vesicular space is present. Under this condition an overshooting uptake of L-but not of D-alanine occurs. The Na+ gradient stimulated uptake of L-alanine is inhibited by L-serine and L-leucine and stimulated when the membrane vesicles had been preloaded with L-alanine, L-serine or L-leucine. The ionophore monensin inhibits stimulation of uptake caused by a sodium gradient. In the presence of valinomycin or carbonyl cyanide p-trifluoromethoxyphenylhydrazone (CFCCP), the sodium-dependent transport is augmented in vesicles preloaded with K2SO4 or H+ ions (intravesicular pH 5.5), respectively. In the presence of different anions, the Na+-dependent transport is stimulated according to increasing anionic penetration through membrane (lipid solubility). We conclude that a sodium dedpendent electrogenic amino acid transport system is present in pancreatic plasma membranes.
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180
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Yamaguchi A, Anraku Y. Mechanism of 3,5-di-tert-butyl-4-hydroxybenzylidene-malononitrile-mediated proton uptake in liposomes. Kinetics of proton uptake compensated by valinomycin-induced K+-efflux. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 501:136-49. [PMID: 23155 DOI: 10.1016/0005-2728(78)90102-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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181
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Chandrasekaran R, Venkataram Prasad BV. The conformation of polypeptides containing alternating L- and D-amino acids. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1978; 5:125-61. [PMID: 363349 DOI: 10.3109/10409237809177142] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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182
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Morton W. The effects of sub-lethal doses of valinomycin, gramicidin D and m-chlorocarbonylcyanidephenylhydrazone (CCP) on the heat resistance of the goldfish, Carassium auratus L. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C: COMPARATIVE PHARMACOLOGY 1978; 59:1-4. [PMID: 75781 DOI: 10.1016/0306-4492(78)90002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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183
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Wikström MK, Saari HT. The mechanism of energy conservation and transduction by mitochondrial cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 462:347-61. [PMID: 201286 DOI: 10.1016/0005-2728(77)90133-5] [Citation(s) in RCA: 144] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxidation of ferrocytochrome c by molecular oxygen catalysed by cytochrome c oxidase (cytochrome aa3) is coupled to translocation of H+ ions across the mitochondrial membrane. The proton pump is an intrinsic property of the cytochrome c oxidase complex as revealed by studies with phospholipid vesicles inlayed with the purified enzyme. As the conformation of cytochrome aa3 is specifically sensitive to the electrochemical proton gradient across the mitochondrial membrane, it is likely that redox energy is primarily conserved as a conformational "strain" in the cytochrome aa3 complex, followed by relaxation linked to proton translocation. Similar principles of energy conservation and transduction may apply on other respiratory chain complexes and on mitochondrial ATP synthase.
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184
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Measurement of fast light-induced disc shrinkage within bovine rod outer segments by means of a light-scattering transient. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 469:113-22. [PMID: 71161 DOI: 10.1016/0005-2736(77)90174-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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185
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Kaethner TM, Bangham AD. Selective compartmentation of the hydration products of carbon dioxide in liposomes, and its role in regulating water movement. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 468:157-61. [PMID: 406915 DOI: 10.1016/0005-2736(77)90158-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Using liposomes, some possible consequences of auxin-stimulated proton secretion in plant tissues are modelled. Liposomes, made specifically permeable to protons and potassium ions, but containing at least one impermeant, swell at a rate which is proportional to the availability and hydration rate of carbon dioxide; the gas functions as a source of proton and dehydrated anion and this enables a net transfer of KHCO3 to take place.
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186
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Ligeti E, Fonyó A. Competitive inhibition of valinomycin-induced K+-transport by Mg2+-ions in liver mitochondria. FEBS Lett 1977; 79:33-6. [PMID: 891931 DOI: 10.1016/0014-5793(77)80344-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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187
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Abstract
The ability of a series of aromatic and alicyclic analogues of 1,2-ethylenedioxydiacetic acids bearing N,N,N',N'-tetra-n-propyl amide or N-methyl-N-carbethoxypentyl amide linkages to enhance the rate of 45Ca2+ efflux from vesicles was studied. The ligands were less potent in enhancing membrane permeability to Ca2+ than A23187 and X537A. Lipid-soluble anions markedly increased the rate and extent of Ca2+ transport mediated by these neutral ligands. The abilities of these synthetic diamide ligands and naturally occurring ionophores to transport Ca2+ across bilayer membranes were sensitive to the lipid composition of the vesicle. The mechanism of Ca2+ transport mediated by this series of synthetic ligands is discussed.
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188
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Schackmann R, Schwartz A, Saccomani G, Sachs G. Cation transport by gastric H+:K+ ATPase. J Membr Biol 1977; 32:361-81. [PMID: 17007 DOI: 10.1007/bf01905228] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A vesicular microsomal fraction isolated from hog fundic mucosa demonstrates the capacity to take up equal amounts of RB+ and Cl-. The amount of the Rb+ uptake is sensitive to the extravesicular osmolarity, and rate of uptake is sensitive to temperature. 86Rb+ efflux is dependent upon the cation composition of the diluting solution. ATP, but not beta-gamma methylene ATP, induces a reversible efflux of 86Rb+ from loaded vesicles, and this is dependent upon a functional K+-ATPase. The ATP induced efflux is not affected by CCCP (carbonyl cyanide m-chlorophenylhydrazone) or TCS (tetrachlorosalicylanilide) nor by lipid soluble ions or valinomycin. Nigericin inhibits the efflux by 40%. Uptake of the lipid soluble ion 14C-SCN- has been demonstrated and is enhanced by ATP only in the presence of valinomycin. The results are consistent with a neutral or isopotential exchange of H+ for Rb+ mediated by K+-ATPase.
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189
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Abstract
The kinetics of the sodium binding to the ionophore monensin (Mon) in methanol has been studied by 23NaNMR spectroscopy. Fast quadrupole relaxation of the bound sodium affected the relaxation rate of the free sodium through an exchange process between these two species. The exchange was found to be dominated by the reaction: Na+ + Mon-in equilibrium MonNa. The dissociation rate constant at 25 degrees C is 63 s(-1), with an activation enthalpy of 10.3 kcal/mol and activation centropy of -15.8 cal/mol deg. These results indicate that the specificity of the binding of sodium ions to monensin is reflectied in the relatively slow dissociation process. The entropy changes indicate that the activated monensin-sodium complex undergoes a conformational change, but the existence of a conformational change in monensin anion prior to complexation is excluded.
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190
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Garty H, Caplan SR. Light-depending rubidium transport in intact Halobacterium halobium cells. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 459:532-45. [PMID: 14683 DOI: 10.1016/0005-2728(77)90052-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The uptake of rubidium in intact Halobacterium halobium cells was followed, and found to be light-dependent. The exchange process is slow, the steady-state rate of 86Rb+/Rb+ exchange being given by k. = 6.3 - 10(-4) min-1. Starved cells exhibited a faster rate than unstarved cells. The influx of 86Rb+ was almost completely blocked in the presence of proton conductors (CCCP, FCCP, and SF 6847), and was sensitive to the presence of the permeant cation TPMP+. Valinomycin very slightly increased the rate of uptake, while 1 - 10(-6) M nigericin showed significant inhibition. On the other hand, release of 86Rb+ was not light-dependent, although still affected by uncouplers, TPMP+, and nigericin. These experimental observations may be explained in terms of a passive flux driven by an electrical potential difference, and influenced by positive isotope interaction within the membrane. In carefully matched influx-efflux studies, the extent of the positive isotope interaction was measured. Using the formal treatment of Kedem and Essig, the ratio (exchange resistance)/(resistance to net flow) for 86Rb+ was found to be 1.7.
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191
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Knauf PA, Fuhrmann GF, Rothstein S, Rothstein A. The relationship between anion exchange and net anion flow across the human red blood cell membrane. J Gen Physiol 1977; 69:363-86. [PMID: 15047 PMCID: PMC2215016 DOI: 10.1085/jgp.69.3.363] [Citation(s) in RCA: 195] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The conductive (net) anion permeability of human red blood cells was determined from net KCl or K2SO4 effluxes into low K+ media at high valinomycin concentrations, conditions under which the salt efflux is limited primarily by the net anion permeability. Disulfonic stilbenes, inhibitors of anion exchange, also inhibited KCl or K2SO4 efflux under these conditions, but were less effective at lower valinomycin concentrations where K+ permeability is the primary limiting factor. Various concentrations of 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) had similar inhibitory effects on net and exchange sulfate fluxes, both of which were almost completely DIDS sensitive. In the case of Cl-, a high correlation was also found between inhibition of net and exchange fluxes, but in this case about 35% of the net flux was insensitive to DIDS. The net and exchange transport processes differed strikingly in their anion selectivity. Net chloride permeability was only four times as high as net sulfate permeability, whereas chloride exchange is over 10,000 times faster than sulfate exchange. Net OH-permeability, determined by an analogous method, was over four orders of magnitude larger than that of Cl-, but was also sensitive to DIDS. These data and others are discussed in terms of the possibility that a common element may be involved in both net and exchange anion transport.
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192
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193
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Fass SJ, Hammerman MR, Sacktor B. Transport of amino acids in renal brush border membrane vesicles. Uptake of the neutral amino acid L-alanine. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)32757-6] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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194
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Cuthbert AW. Aspects of the pharmacology of passive ion transfer across cell membranes. PROGRESS IN MEDICINAL CHEMISTRY 1977; 14:1-50. [PMID: 76323 DOI: 10.1016/s0079-6468(08)70146-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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195
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Berner W, Kinne R, Murer H. Phosphate transport into brush-border membrane vesicles isolated from rat small intestine. Biochem J 1976; 160:467-74. [PMID: 13784 PMCID: PMC1164262 DOI: 10.1042/bj1600467] [Citation(s) in RCA: 226] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Uptake of Pi into brush-border membrane vesicles isolated from rat small intestine was investigated by a rapid filtration technique. The following results were obtained. 1. At pH 7.4 in the presence of a NaCl gradient across the membrane (sodium concentration in the medium higher than sodium concentration in the vesicles), phosphate was taken up by a saturable transport system, which was competitively inhibited by arsenate. Phosphate entered the same osmotically reactive space as D-glucose, which indicates that transport into the vesicles rather than binding to the membranes was determined. 2. The amount of phosphate taken up initially was increased about fourfold by lowering the pH from 7.4 to 6.0.3. When Na+ was replaced by K+, Rb+ or Cs+, the initial rate of uptake decreased at pH 7.4 but was not altered at pH 6.0.4. Experiments with different anions (SCN-,Cl-, SO42-) and with ionophores (valinomycin, monactin) showed that at pH 7.4 phosphate transport in the presence of a Na+ gradient is almost independent of the electrical potential across the vesicle membrane, whereas at pH 6.0 phosphate transport involves the transfer of negative charge. It is concluded that intestinal brush-border membranes contain a Na+/phosphate co-transport system, which catalyses under physiological conditions an electroneutral entry of Pi and Na+ into the intestinal epithelial cell. In contrast with the kidney, probably univalent phosphate and one Na+ ion instead of bivalent phosphate and two Na+ ions are transported together.
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196
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Ivey JL, Wright DR, Tashjian AH. Bone resorption in organ culture: inhibition by the divalent cation ionophores A23187 and X-537A. J Clin Invest 1976; 58:1327-38. [PMID: 186489 PMCID: PMC333304 DOI: 10.1172/jci108588] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ionophores A23187 and X-537A were used as probes to investigate the possible role of calcium uptake by bone as a mediator for the stimulation of bone resorption induced by parathyroid hormone (PTH) and other agents in cultured mouse calvaria. The ionophores alone at concentrations from 1 nM to 20 muM did not stimulate bone resorption, nor did they potentiate bone resorption stimulated by submaximal concentrations of PTH after either brief (15-60 min) or extended (1-3 day) exposure to the ionophores. Unexpectedly, we found that the ionophores inhibit in a dose-dependent manner bone resorption stimulated by PTH and a wide variety of other compounds (prostaglandin E2, 1alpha-hydroxycholecalciferol, 3-isobutyl-1-methyl-xanthine, and phorbol myristate acetate). This inhibition was not due to irreversible damage to the bones by the ionophores, because the inhibition was reversible even after 24 h of treatment. Inhibition of bone resorption by the ionophores was observed in media of both high and low calcium concentration, indicating that the inhibition was not due to a critical extracellular calcium concentration. Inhibition by the ionophores differs qualitatively in several ways from that produced by calcitonin, a natural inhibitor of bone resorption. Furthermore, A23187 at 1.0 mug/ml had no effect on the accumulation of cyclic AMP in the medium of either control, PTH- or calcitonin treated calvaria. We conclude that the ionophores A23187 or X537A do not stimulate bone resorption nor potentiate the effects of stimulators of bone resorption; instead they are inhibitors of bone resorption stimulated by a wide variety of compounds.
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197
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Hladky SB, Rink TJ. Potential difference and the distribution of ions across the human red blood cell membrane; a study of the mechanism by which the fluorescent cation, diS-C3-(5) reports membrane potential. J Physiol 1976; 263:287-319. [PMID: 14255 PMCID: PMC1307701 DOI: 10.1113/jphysiol.1976.sp011632] [Citation(s) in RCA: 112] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
1. The mechanism by which the fluorescent, cationic dye diS-C3-(5) responds to the membrane potential of red blood cells has been investigated. 2. The dye in aqueous solution absorbs most strongly at 650 nm. Addition of white, haemoglobin-free membranes red shifts the absorption maximum ca. 20 nm, while addition of membrane-free cell lysate results in the appearance of a new dye absorption peak at 590 nm. Thus the dye binds both to cell membranes and to cell contents. The component of the cytoplasm which binds the dye is non-dialysable, presumably haemoglobin. 3. Dye added to a suspension of intact cells shows a strong absorption at 590 nm indicating that the dye has bound to the cell contents and that the membrane is permeable to the dye. 4. The amount of dye which partitions into (and on to) the cells can be determined, as reported by Sims, Waggoner, Wang & Hoffman (1974), from the fluorescence of the dye remaining in the supernatant after the cells are centrifuged to the bottom of the suspension. In most conditions the proportion of the cell associated dye which is either free inside the cell or bound to the outside face of the membrane is negligible compared to the proportion bound to the cell contents. 5. On the assumption that the dye is not actively transported, the ratio of the equilibrium dye activities inside and outside the cell, ai/ao, is determined by the membrane potential according to the Nernst relation. Driving the membrane potenial negative then increases the cell associated dye by increasing the activity ratio and hence ai and the amount of dye bound to cell contents. 6. At the known Donnan equilibrium potential the internal dye activity can be calculated from the external activity. An empirical relation between cell associated dye and internal activity has been determined by measuring the dye partition between cells and medium at different external activities. 7. Using this empirial relation, and providing that any changes in cell composition do not affect the dye binding, the internal activity at any potential can be calculated from the measured amount of cell associated dye. The external activity can be estimated fluorimetrically. The membrane potential is then calculated from the activity ratio. 8. The membrane potenial of cells has been altered by adding valinomycin in the presence of different K gradients. Under the conditions used, the 'constant field' permeability for K-Val is 15-20 times that of Cl. 9. Dye binding to haemoglobin is influenced by pH and thus dye partitioning into cells changes with intracellular pH. Increasing intracellular pH increases the amount of dye partitioned, while decreasing pH decreases this amount. 10. When large potentials are produced with valinomycin there is no change in intracellular pH. This result indicates that in red blood cells intracellular pH is determined by the external pH and the Cl concentration ratio and not by the membrane potentials. 11. DiS-C3-(5) can be used to estimate potentials across resealed ghost membranes...
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198
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199
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Reed PW. Effects of divalent cation ionophore A23187 on potassium permeability of rat erythrocytes. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33464-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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200
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Liedtke CM, Hopfer U. Anion transport in brush border membranes isolated from rat small intestine. Biochem Biophys Res Commun 1976; 76:579-85. [PMID: 17408 DOI: 10.1016/0006-291x(77)90763-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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