Abstract
The dependence on pH and membrane potential of the pore formed by colicin A and its C-terminal 20 kDa fragment has been measured using planar lipid bilayers. The single channel conductance of the pore formed by both colicin A and the fragment increases with pH with an apparent pK of 6.0. At pH 5.0 the gating by membrane potential of the channels formed by either colicin A or its fragment is identical. At the same pH, quite similar pore properties were found when using the related bacteriocin, colicin E1. In agreement with previous studies, these data indicate that the protein structure containing the lumen of the pore resides in the 20 kDa C-terminal part of the colicin A and favours the recently proposed model, based on protein sequence analysis, which proposes that colicin A, E1 and IB C-terminal domains are folded in the same three-dimensional structure. However, it is also shown that colicin A and not its C-terminal fragment undergoes a pH dependent transition between an “acidic” and a “basic” form of the pore with an apparent pK of 5.3. The two forms of the pore differ by their gating charge but not by the channel size. These results suggest that there is a pH dependent association between the C-terminal domain carrying the lumen of the pore and another domain of the molecule which affect the pore sensitivity to membrane potential.
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References
Baumann G, Easton G (1980) Micro and macrokinetic behaviour of the subunit gating channel. J Membr Biol 52: 237–243
Brunden KR, Uratani Y, Cramer WA (1984) Dependence of the conformation of a colicin E1 channel-forming peptide on acidic pH and solvent polarity. J Biol Chem 259: 7682–7687
Bullock J, Cohen F, Dankert J, Cramer WA (1983) Comparison of the macroscopic and single channel conductance properties of colicin E1 and its C-terminal tryptic peptide. J Biol Chem 258:9908–9912
Cavard D, Lazdunski C (1979) Purification and molecular properties of a new colicin. Eur J Biochem 96:517–524
Cavard D, Crozel V, Gorvel J-P, Pattus F, Baty D, Lazdunski C (1986) A molecular, genetic and immunological approach to the functioning of colicin A: a pore-forming protein. J Mol Biol 187:449–459
Cleveland BM, Slatin G, Finkelstein A, Levinthal C (1983) Structure function relationships for a voltage-dependent ion channel: properties of COOH-terminal fragments of colicin E1. J Biol Chem 257:3857–3863
Dankert J, Uratani Y, Grabeau C, Cramer WA, Hermodson M (1982) On a domain structure of colicin E1. Proc Natl Acad Sci USA 80:3706–3710
Davidson VL, Brunden KR, Cramer WA, Cohen FS (1984a) Studies on the mechanism of channel-forming colicins using artificial membranes. J Membr Biol 79:109–118
Davidson VL, Cramer WA, Bishop LJ, Brunden KR (1984b) Dependence of the activity of colicin E1 in artificial membrane vesicles on pH, membrane potential and vesicle size. J Biol Chem 259:594–600
Davidson VL, Brunden KR, Cramer WA (1985) Acidic pH requirement for insertion of colicin E1 into artificial membrane vesicles: Relevance to the mechanism of action of colicins and certain toxins. Proc Natl Acad Sci USA 82: 1386–1390
Ehrenstein G, Blumenthal R, Latorre R, Lecar H (1974) Kinetics of opening and closing of individual excitability-inducing material channels in a lipid bilayer. J Gen Physiol 63:707–721
Guy HR (1983) A model of colicin E1 membrane channel protein structure. Biophys J 41:363a (abstr)
Hodgkin AL, Huxley AF (1952) A quantitative description of membrane current and its application to conductance and excition in nerve. J Physiol 117:500–544
Kagawa Y, Racker E (1971) Partial resolution of the enzymes catalyzing oxidative phosphorylation XIV. Reconstitution of particles catalyzing 32Pi-adenosine triphosphate exchange. J Biol Chem 246:5477–5487
Konisky J (1982) Colicins and other bacteriocins with established modes of action. Annu Rev Microbiol 36:125–144
Latorre R, Ehrenstein G, Lecar H (1972) Ion transport through excitability inducing material (EM) channels in lipid bilayer membranes. J Gen Physiol 60:72–85
Martinez C, Lazdunski C, Pattus F (1983) Isolation, molecular and functional properties of the C-terminal domain of colicin A. EMBO J 2:1501–1517
Ohno-Ywashita Y, Imahori K (1982) Assignment of the functional loci in the colicin E1 molecule by characterization of its proteolytic fragments. J Biol Chem 2517:6446–6451
Pattus F, Cavard D, Verger R, Lazdunski C, Rosenbusch JP, Schindler H (1983a) Formation of voltage dependent pores in planar bilayers by colicin A. In: Spach G (ed) Physical chemistry of transmembrane ion motions. Elsevier, Amsterdam, pp 407–413
Pattus F, Martinez MC, Dargent B, Cavard D, Verger R, Lazdunski C (1983b) Interaction of colicinA with phospholipid monolayers and liposomes. Biochemistry 22: 5698–5703
Pattus F, Cavard D, Crozel V, Baty D, Adrian M, Lazdunski C (1985a) pH dependent membrane fusion is promoted by various colicins. EMBO J 4:2467–2474
Pattus F, Heitz F, Martinez C, Provencher SW, Lazdunski C (1985b) Secondary structure of the pore-forming colicinA and its C-terminal fragment. Eur J Biochem 152:681–689
Pugsley AP (1984a) The ins and outs of colicins. Part I: Production and translocation across membrane. Microbiol Sci 1:168–175
Pugsley AP (1984b) The ins and outs of colicins. Part II: Lethal action, immunity and ecological implications. Microbiol Sci 1:203–205
Raymond L, Slatin SL, Finkelstein A (1985) Channels formed by colicinE1 in planar lipid bilayers are large and exhibit pH-dependent ion selectivity. J Membr Biol 84:173–182
Schein S, Kagan B, Finkelstein A (1978) Colicin K acts by forming voltage dependent channels in phospholipid bilayer membranes. Nature 276:159–163
Schindler H (1980) Formation of planar bilayers from artificial or native membrane vesicles. FEBS Lett 122:77–79
Schindler H, Feher C (1976) Branched bimolecular lipid membranes. Biophys J 16:1107–1113
Schwarz G (1978) On the physico-chemical basis of voltagedependent molecular gating mechanisms in biological membranes. J Membr Biol 43:127–148
Seta P, d'Epenoux B, Sandeaux R, Pattus F, Lazdunski C, Gavach C (1983) Voltage and time dependence of the conductance of planar lipid bilayers doped with colicinA. Biochem Biophys Res Commun 113(3):765–771
Tokuda H, Konisky J (1978) In vitro depolarization of Escherichia coli membrane vesicles by colicin IA. J Biol Chem 253:7731–7737
Wilmsen HV, Faultisch H, Eibl H, Boheim G (1985) Phallolysin. A mushroom toxin, forms proton and voltage-gated membrane channels. Eur Biophys J 12:199–209
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Collarini, M., Amblard, G., Lazdunski, C. et al. Gating processes of channels induced by colicin A, its C-terminal fragment and colicin E1 in planar lipid bilayers. Eur Biophys J 14, 147–153 (1987). https://doi.org/10.1007/BF00253839
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DOI: https://doi.org/10.1007/BF00253839