Abstract
Effects of D2O were studied on internodal cells of the freshwater alga Nitellopsis obtusa under plasmalemma perfusion (tonoplast-free cells) with voltage clamp, and on Ca2+ channels isolated from the alga and reconstituted in bilayer lipid membranes (BLM). External application of artificial pond water (APW) with D2O as the solvent to the perfused plasmalemma preparation led to an abrupt drop of membrane resistance (R m = 0.12 ±0.03 kΩ · cm2), thus preventing further voltage clamping. APW with 25% D2O caused a two-step reduction of R m : first, down to 2.0 ± 0.8 kΩ · cm2, and then further to 200 Ω · cm2, in 2 min. It was shown that in the first stage, Ca2+ channels are activated, and then, Ca2+ ions entering through them activate the Cl− channels. The Ca2+ channels are activated irreversibly. If 100 mm CsCl was substituted for 200 mm sucrose (introduced for isoosmoticity), no effect of D2O on R m was observed. Intracellular H2O/D2O substitution also did not change R m . In experiments on single Ca2+ channels in BLM H2O/ D2O substitution in a solution containing 100 mm KCl (trans side) produced no effect on channel activity, while in 10 mm KCl, at negative voltage, the open channel probability sharply increased. This effect was irreversible. The single channel conductance was not altered after the H2O/D2O substitution. The discussion of the possible mechanism of D2O action on Ca2+ and Cl− channels was based on an osmotic-like stress effect and the phenomenon of higher D-bond energy compared to the H-bond.
Similar content being viewed by others
References
Alexandre, J., Lassalles, J.P. 1991. Hydrostatic and osmotic pressure activated channel in plant vacuole. Biophys. J. 60:1326–1336
Andjus, P.R., Srejić, R., Vučelić, D. 1987. The temperature peaks of cell membrane permeability. In: Structure, Dynamics and Function of Biomolecules, A. Ehrenberg, R. Rigler, A. Gräslund, L. Nilsson, editors, pp 299–302. Springer-Verlag, Berlin
Andjus, P.R., Vučelić, D. 1990. D2O-induced cell excitation. J. Membrane Biol. 115:123–127
Bass, L., Moore, W.J. 1973. The role of protons in nerve conduction. Prog. Biophys. Mol. Biol. 27:145–171
Brooks, S.C. 1937. Osmotic effects of deuterium oxide (heavy water) on living cells. Science 86:497–498
Calvin, M., Hermans, J., Sheraga, H.A. 1959. Effects of deuterium on the strength of hydrogen bonds. J. Amer. Chem. Soc. 81:5048–5050
Collander, R. 1954. The permeability of Nitella cells to nonelectrolytes. Physiol. Plant 7:420–445
Conti, F., Palmieri, L. 1968. Nerve fiber behaviour in heavy water under voltage clamp. Biophysik 5:71–77
Cosgrove, D.J., Hedrich, R. 1991. Stretch-activated chloride, potassium, and calcium channels coexisting in plasma membranes of guard cells in Vicia faba L. Planta 186:143–153
Crank, J. 1956. The Mathematics of Diffusion. Clarendon, Oxford
Dainty, J., Ginzburg, B.Z. 1964. The reflection coefficient of plant cell membranes for certain solutes. Biochim. Biophys. Acta 79:129–134
Grischenko, V.M., Aleksandrov, A.A., Berestovsky, G.N. 1984. Isolation of a fraction of cytoplasmic proteins possessing channelforming activity from characeous algae. Soviet Plant Physiol. 31:787–793
Hermans, J.J., Scheraga, H.A. 1959. The thermally induced configurational change of ribonuclease in H2O and D2O. Biochim. Biophys. Acta 36:534–535
Karasz, E.E., Gajnos, G.E. 1976. Relative stability of the α-helix of deuterated poly(γ-benzyl-l-glutamate). Biopolymers 15:1939–1950
Kataev, A.A., Zherelova, O.M., Berestovsky, G.N. 1984. Ca2+-induced activation and irreversible inactivation of chloride channels in the perfused plasmalemma of Nitellopsis obtusa. Gen. Physiol. Biophys. 3:447–462
Katsuhara, M., Tazawa, M. 1986. Salt tolerance in Nitellopsis obtusa. Protoplasma 135:155–161
Lewin, S. 1974. Displacement of Water and its Control of Biochemical Reaction. Academic, London, New York
Lindley, B.D., Hoshiko, T., Leb, D.E. 1964. Effects of D2O and osmotic gradients on potential and resistance of the isolated frog skin. J. Gen. Physiol. 47:773–793
Lunevsky, V.Z., Zherelova, O.M., Aleksandrov, A.A., Vinokurov, M.G., Berestovsky, G.N. 1980. Model of the selective calcium channel of the cells of characean alga. Biophysics 25:699–706
Lunevsky, V.Z., Zherelova, O.M., Vostrikov, I.Y., Berestovsky, G.N. 1983. Excitation of Characeae cell membranes as a result of activation of calcium and chloride channels. J. Membrane Biol. 72:43–58
Muller-Mohussen, M., Albrecht-Buhler, G. 1969. Der Einfluss von schwerem Wasse ouf das stationäre Strom-Spannungsverhalten des Ranvierschen Schnurrings. Pfluegers Arch. 305:65–67
Schauf, C.L., Bullock, J.O. 1979. Modification of sodium channel gating in Myxicola giant axons by deuterium oxide, temperature and internal cations. Biophys. J. 27:193–208
Scheraga, H.A. 1960. Helix-coil transformation in deuterated macromolecules. Ann. NY Acad. Sci. 16:608–616
Singh, T.R., Wood, J.L. 1969. Isotope effect on the hydrogen bond length. J. Chem. Phys. 50:3572–3576
Smith, P.T., Walker, N.A. 1981. Studies on the perfused plasmalemma of Chara corallina: I. Current-voltage curves: ATP and potassium dependence. J. Membrane Biol. 60:223–236
Spyropoulos, C.S., Ezzy, M.E. 1959. Nerve fiber activity in heavy water. Amer. J. Physiol. 197:808–812
Stillman, J.M., Binstock, L. 1967. The deuterium effect studied in the squid giant axon. Biophys. Soc. Abstr. 7:20
Tazawa, M., Kikuyama, M., Shimmen, T. 1976. Electric characteristics and cytoplasmic streaming of Characeae cells lacking tonoplast. Cell Struct. Fund. 1:165–176
Tester, M. 1990. Plant ion channels: whole-cell and single-channel studies. New Phytol. 114:305–340
Tsien, R.W., Hess, P., McCleskey, E.W., Rosenberg, R.L. 1987. Calcium channels: Mechanisms of selectivity, permeation, and block. Annu. Rev. Biophys. Biophys. Chem. 16:265–290
Williamson, R.E. 1975. Cytoplasmic streaming in Chara: A cell model activated by ATP and inhibited be cytochalasin B. J. Cell Sci. 17:655–665
Zherelova, O.M., Kataev, A.A., Berestovsky, G.N. 1985. The necessity of ATP and Mg2+ for maintenance of the functional activity of the calcium channels of Charophyta algae. Biophysics 280–282:37–39
Author information
Authors and Affiliations
Additional information
We are indebted to Dr. Igor I. Pottosin for his constant help in discussions during the experimental phase as well as in the course of manuscript preparation.
Rights and permissions
About this article
Cite this article
Andjus, P.R., Kataev, A.A., Alexandrov, A.A. et al. D2O-induced ion channel activation in Characeae at low ionic strength. J. Membarin Biol. 142, 43–53 (1994). https://doi.org/10.1007/BF00233382
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00233382