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. 2000 Apr;78(4):1825–1834. doi: 10.1016/S0006-3495(00)76732-4

Proton mobilities in water and in different stereoisomers of covalently linked gramicidin A channels.

S Cukierman 1
PMCID: PMC1300777  PMID: 10733963

Abstract

Proton conductivities in bulk solution (lambda(H)) and single-channel proton conductances (g(H)) in two different stereoisomers of the dioxolane-linked gramicidin A channel (the SS and RR dimers) were measured in a wide range of bulk proton concentrations ([H], 0.1-8000 mM). Proton mobilities (micro(H)) in water as well as in the SS and RR dimers were calculated from the conductivity data. In the concentration range of 0.1-2000 mM, a straight line with a slope of 0.75 describes the log (g(H))-log ([H]) relationship in the SS dimer. At [H] > 2000 mM, saturation is followed by a decline in g(H). The g(H)-[H] relationship in the SS dimer is qualitatively similar to the [H] dependence of lambda(H). However, the slope of the straight line in the log(lambda(H))-log([H]) plot is 0.96, indicating that the rate-limiting step for proton conduction through the SS dimer is not the diffusion of protons in bulk solution. The significant difference between the slopes of those linear relationships accounts for the faster decline of micro(H) as a function of [H] in the SS dimer in relation to bulk solution. In the high range of [H], saturation and decline of g(H) in the SS dimer can be accounted for by the significant decrease of micro(H) in bulk solution. At any given [H], g(H) in the RR dimer is significantly smaller than in the SS. Moreover, the g(H)-[H] relationship in the RR stereoisomer is qualitatively different from that in the SS. Between 1 and 50 mM [H], g(H) can be fitted with an adsorption isotherm, suggesting the presence of a proton-binding site inside the pore (pK(a) approximately 2), which limits proton exit from the channel. At 100 mM < [H] < 3000 mM, g(H) increases linearly with [H]. The distinctive shape of the g(H)-[H] relationship in the RR dimer suggests that the channel can be occupied simultaneously by more than one proton. At higher [H], the saturation and decline of g(H) in the RR dimer reflect the properties of micro(H) in bulk solution. In the entire range of [H], protons seem to cross the SS and RR channels via a Grotthuss-like mechanism. The rate-limiting step for proton transfer in the SS dimer is probably the membrane-channel/bulk solution interface. It is also proposed that the smaller g(H) in the RR dimer is the consequence of a different organization and dynamics of the H-bonded network of water molecules inside the pore of the channel, resulting in a slower proton transfer and multiple pore occupancy by protons.

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Selected References

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  1. Akeson M., Deamer D. W. Proton conductance by the gramicidin water wire. Model for proton conductance in the F1F0 ATPases? Biophys J. 1991 Jul;60(1):101–109. doi: 10.1016/S0006-3495(91)82034-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Andersen O. S. Gramicidin channels. Annu Rev Physiol. 1984;46:531–548. doi: 10.1146/annurev.ph.46.030184.002531. [DOI] [PubMed] [Google Scholar]
  3. Andersen O. S. Ion movement through gramicidin A channels. Studies on the diffusion-controlled association step. Biophys J. 1983 Feb;41(2):147–165. doi: 10.1016/S0006-3495(83)84416-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Arseniev A. S., Barsukov I. L., Bystrov V. F., Lomize A. L., Ovchinnikov YuA 1H-NMR study of gramicidin A transmembrane ion channel. Head-to-head right-handed, single-stranded helices. FEBS Lett. 1985 Jul 8;186(2):168–174. doi: 10.1016/0014-5793(85)80702-x. [DOI] [PubMed] [Google Scholar]
  5. Baciou L., Michel H. Interruption of the water chain in the reaction center from Rhodobacter sphaeroides reduces the rates of the proton uptake and of the second electron transfer to QB. Biochemistry. 1995 Jun 27;34(25):7967–7972. doi: 10.1021/bi00025a001. [DOI] [PubMed] [Google Scholar]
  6. Breed J., Sankararamakrishnan R., Kerr I. D., Sansom M. S. Molecular dynamics simulations of water within models of ion channels. Biophys J. 1996 Apr;70(4):1643–1661. doi: 10.1016/S0006-3495(96)79727-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Busath D. D. The use of physical methods in determining gramicidin channel structure and function. Annu Rev Physiol. 1993;55:473–501. doi: 10.1146/annurev.ph.55.030193.002353. [DOI] [PubMed] [Google Scholar]
  8. Busath D., Szabo G. Permeation characteristics of gramicidin conformers. Biophys J. 1988 May;53(5):697–707. doi: 10.1016/S0006-3495(88)83151-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Chiu S. W., Subramaniam S., Jakobsson E. Simulation study of a gramicidin/lipid bilayer system in excess water and lipid. I. Structure of the molecular complex. Biophys J. 1999 Apr;76(4):1929–1938. doi: 10.1016/S0006-3495(99)77352-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Chiu S. W., Subramaniam S., Jakobsson E. Simulation study of a gramicidin/lipid bilayer system in excess water and lipid. II. Rates and mechanisms of water transport. Biophys J. 1999 Apr;76(4):1939–1950. doi: 10.1016/S0006-3495(99)77353-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cross T. A. Solid-state nuclear magnetic resonance characterization of gramicidin channel structure. Methods Enzymol. 1997;289:672–696. doi: 10.1016/s0076-6879(97)89070-2. [DOI] [PubMed] [Google Scholar]
  12. Crouzy S., Woolf T. B., Roux B. A molecular dynamics study of gating in dioxolane-linked gramicidin A channels. Biophys J. 1994 Oct;67(4):1370–1386. doi: 10.1016/S0006-3495(94)80618-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Cukierman S., Quigley E. P., Crumrine D. S. Proton conduction in gramicidin A and in its dioxolane-linked dimer in different lipid bilayers. Biophys J. 1997 Nov;73(5):2489–2502. doi: 10.1016/S0006-3495(97)78277-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Dani J. A., Levitt D. G. Water transport and ion-water interaction in the gramicidin channel. Biophys J. 1981 Aug;35(2):501–508. doi: 10.1016/S0006-3495(81)84805-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. DeCoursey T. E., Cherny V. V. Temperature dependence of voltage-gated H+ currents in human neutrophils, rat alveolar epithelial cells, and mammalian phagocytes. J Gen Physiol. 1998 Oct;112(4):503–522. doi: 10.1085/jgp.112.4.503. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. DeCoursey T. E., Cherny V. V. Voltage-activated hydrogen ion currents. J Membr Biol. 1994 Sep;141(3):203–223. doi: 10.1007/BF00235130. [DOI] [PubMed] [Google Scholar]
  17. Decker E. R., Levitt D. G. Use of weak acids to determine the bulk diffusion limitation of H+ ion conductance through the gramicidin channel. Biophys J. 1988 Jan;53(1):25–32. doi: 10.1016/S0006-3495(88)83062-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Eisenman G., Enos B., Hägglund J., Sandblom J. Gramicidin as an example of a single-filing ionic channel. Ann N Y Acad Sci. 1980;339:8–20. doi: 10.1111/j.1749-6632.1980.tb15964.x. [DOI] [PubMed] [Google Scholar]
  19. Finkelstein A., Andersen O. S. The gramicidin A channel: a review of its permeability characteristics with special reference to the single-file aspect of transport. J Membr Biol. 1981 Apr 30;59(3):155–171. doi: 10.1007/BF01875422. [DOI] [PubMed] [Google Scholar]
  20. Hille B., Schwarz W. Potassium channels as multi-ion single-file pores. J Gen Physiol. 1978 Oct;72(4):409–442. doi: 10.1085/jgp.72.4.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hladky S. B., Haydon D. A. Ion transfer across lipid membranes in the presence of gramicidin A. I. Studies of the unit conductance channel. Biochim Biophys Acta. 1972 Aug 9;274(2):294–312. doi: 10.1016/0005-2736(72)90178-2. [DOI] [PubMed] [Google Scholar]
  22. Ketchem R., Roux B., Cross T. High-resolution polypeptide structure in a lamellar phase lipid environment from solid state NMR derived orientational constraints. Structure. 1997 Dec 15;5(12):1655–1669. doi: 10.1016/s0969-2126(97)00312-2. [DOI] [PubMed] [Google Scholar]
  23. Koeppe R. E., 2nd, Anderson O. S. Engineering the gramicidin channel. Annu Rev Biophys Biomol Struct. 1996;25:231–258. doi: 10.1146/annurev.bb.25.060196.001311. [DOI] [PubMed] [Google Scholar]
  24. Kovacs F., Quine J., Cross T. A. Validation of the single-stranded channel conformation of gramicidin A by solid-state NMR. Proc Natl Acad Sci U S A. 1999 Jul 6;96(14):7910–7915. doi: 10.1073/pnas.96.14.7910. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Levitt D. G., Decker E. R. Electrostatic radius of the gramicidin channel determined from voltage dependence of H+ ion conductance. Biophys J. 1988 Jan;53(1):33–38. doi: 10.1016/S0006-3495(88)83063-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Levitt D. G., Elias S. R., Hautman J. M. Number of water molecules coupled to the transport of sodium, potassium and hydrogen ions via gramicidin, nonactin or valinomycin. Biochim Biophys Acta. 1978 Sep 22;512(2):436–451. doi: 10.1016/0005-2736(78)90266-3. [DOI] [PubMed] [Google Scholar]
  27. Läuger P. Diffusion-limited ion flow through pores. Biochim Biophys Acta. 1976 Dec 2;455(2):493–509. doi: 10.1016/0005-2736(76)90320-5. [DOI] [PubMed] [Google Scholar]
  28. Martinez S. E., Huang D., Ponomarev M., Cramer W. A., Smith J. L. The heme redox center of chloroplast cytochrome f is linked to a buried five-water chain. Protein Sci. 1996 Jun;5(6):1081–1092. doi: 10.1002/pro.5560050610. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Myers V. B., Haydon D. A. Ion transfer across lipid membranes in the presence of gramicidin A. II. The ion selectivity. Biochim Biophys Acta. 1972 Aug 9;274(2):313–322. doi: 10.1016/0005-2736(72)90179-4. [DOI] [PubMed] [Google Scholar]
  30. Nagle J. F., Morowitz H. J. Molecular mechanisms for proton transport in membranes. Proc Natl Acad Sci U S A. 1978 Jan;75(1):298–302. doi: 10.1073/pnas.75.1.298. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Nagle J. F., Tristram-Nagle S. Hydrogen bonded chain mechanisms for proton conduction and proton pumping. J Membr Biol. 1983;74(1):1–14. doi: 10.1007/BF01870590. [DOI] [PubMed] [Google Scholar]
  33. Phillips L. R., Cole C. D., Hendershot R. J., Cotten M., Cross T. A., Busath D. D. Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin. Biophys J. 2008 Nov 21;77(5):2492–2501. doi: 10.1016/S0006-3495(99)77085-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Pomès R., Roux B. Free energy profiles for H+ conduction along hydrogen-bonded chains of water molecules. Biophys J. 1998 Jul;75(1):33–40. doi: 10.1016/S0006-3495(98)77492-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Pomès R., Roux B. Structure and dynamics of a proton wire: a theoretical study of H+ translocation along the single-file water chain in the gramicidin A channel. Biophys J. 1996 Jul;71(1):19–39. doi: 10.1016/S0006-3495(96)79211-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Quigley E. P., Emerick A. J., Crumrine D. S., Cukierman S. Attenuation of proton currents by methanol in a dioxolane-linked gramicidin A channel in different lipid bilayers. Biophys J. 1998 Dec;75(6):2811–2820. doi: 10.1016/S0006-3495(98)77724-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Quigley E. P., Quigley P., Crumrine D. S., Cukierman S. The conduction of protons in different stereoisomers of dioxolane-linked gramicidin A channels. Biophys J. 1999 Nov;77(5):2479–2491. doi: 10.1016/S0006-3495(99)77084-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Riistama S., Hummer G., Puustinen A., Dyer R. B., Woodruff W. H., Wikström M. Bound water in the proton translocation mechanism of the haem-copper oxidases. FEBS Lett. 1997 Sep 8;414(2):275–280. doi: 10.1016/s0014-5793(97)01003-x. [DOI] [PubMed] [Google Scholar]
  39. SARGES R., WITKOP B. GRAMICIDIN A. V. THE STRUCTURE OF VALINE- AND ISOLEUCINE-GRAMICIDIN A. J Am Chem Soc. 1965 May 5;87:2011–2020. doi: 10.1021/ja01087a027. [DOI] [PubMed] [Google Scholar]
  40. Sansom M. S., Kerr I. D., Breed J., Sankararamakrishnan R. Water in channel-like cavities: structure and dynamics. Biophys J. 1996 Feb;70(2):693–702. doi: 10.1016/S0006-3495(96)79609-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Stankovic C. J., Heinemann S. H., Delfino J. M., Sigworth F. J., Schreiber S. L. Transmembrane channels based on tartaric acid-gramicidin A hybrids. Science. 1989 May 19;244(4906):813–817. doi: 10.1126/science.2471263. [DOI] [PubMed] [Google Scholar]

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