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. 1990 Nov;58(5):1207–1212. doi: 10.1016/S0006-3495(90)82461-9

Gramicidins A, B, and C form structurally equivalent ion channels.

D B Sawyer 1, L P Williams 1, W L Whaley 1, R E Koeppe 2nd 1, O S Andersen 1
PMCID: PMC1281065  PMID: 1705449

Abstract

The membrane structure of the naturally occurring gramicidins A, B, and C was investigated using circular dichroism (CD) spectroscopy and single-channel recording techniques. All three gramicidins form channels with fairly similar properties (Bamberg, E., K. Noda, E. Gross, and P. Läuger. 1976. Biochim. Biophys. Acta. 419:223-228.). When incorporated into lysophosphatidylcholine micelles, however, the CD spectrum of gramicidin B is different from that of gramicidin A or C (cf. Prasad, K. U., T. L. Trapane, D. Busath, G. Szabo, and D. W. Urry. 1983. Int. J. Pept. Protein Res. 22:341-347.). The structural identity of the channels formed by gramicidin B has, therefore, been uncertain. We find that when gramicidins A and B are incorporated into dipalmitoylphosphatidylcholine vesicles, their CD spectra are fairly similar, suggesting that the two channel structures could be similar. In planar bilayers, gramicidins A, B, and C all form hybrid channels with each other. The properties of the hybrid channels are intermediate to those of the symmetric channels, and the appearance rates of the hybrid channels (relative to the symmetric channels) corresponds to what would be predicted if all three gramicidin molecules were to form structurally equivalent channels. These results allow us to interpret the different behavior of channels formed by the three gramicidins solely on the basis of the amino acid substitution at position 11.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Andersen O. S. Ion movement through gramicidin A channels. Single-channel measurements at very high potentials. Biophys J. 1983 Feb;41(2):119–133. doi: 10.1016/S0006-3495(83)84414-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Andersen O. S., Muller R. U. Monazomycin-induced single channels. I. Characterization of the elementary conductance events. J Gen Physiol. 1982 Sep;80(3):403–426. doi: 10.1085/jgp.80.3.403. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bamberg E., Noda K., Gross E., Läuger P. Single-channel parameters of gramicidin A,B, and C. Biochim Biophys Acta. 1976 Jan 21;419(2):223–228. doi: 10.1016/0005-2736(76)90348-5. [DOI] [PubMed] [Google Scholar]
  4. Barrow D. A., Lentz B. R. Large vesicle contamination in small, unilamellar vesicles. Biochim Biophys Acta. 1980 Mar 27;597(1):92–99. doi: 10.1016/0005-2736(80)90153-4. [DOI] [PubMed] [Google Scholar]
  5. Durkin J. T., Koeppe R. E., 2nd, Andersen O. S. Energetics of gramicidin hybrid channel formation as a test for structural equivalence. Side-chain substitutions in the native sequence. J Mol Biol. 1990 Jan 5;211(1):221–234. doi: 10.1016/0022-2836(90)90022-E. [DOI] [PubMed] [Google Scholar]
  6. Killian J. A., Prasad K. U., Hains D., Urry D. W. The membrane as an environment of minimal interconversion. A circular dichroism study on the solvent dependence of the conformational behavior of gramicidin in diacylphosphatidylcholine model membranes. Biochemistry. 1988 Jun 28;27(13):4848–4855. doi: 10.1021/bi00413a040. [DOI] [PubMed] [Google Scholar]
  7. Killian J. A., de Kruijff B., van Echteld C. J., Verkleij A. J., Leunissen-Bijvelt J., de Gier J. Mixtures of gramicidin and lysophosphatidylcholine form lamellar structures. Biochim Biophys Acta. 1983 Feb 9;728(1):141–144. doi: 10.1016/0005-2736(83)90446-7. [DOI] [PubMed] [Google Scholar]
  8. Koeppe R. E., 2nd, Paczkowski J. A., Whaley W. L. Gramicidin K, a new linear channel-forming gramicidin from Bacillus brevis. Biochemistry. 1985 Jun 4;24(12):2822–2826. doi: 10.1021/bi00333a002. [DOI] [PubMed] [Google Scholar]
  9. LoGrasso P. V., Moll F., 3rd, Cross T. A. Solvent history dependence of gramicidin A conformations in hydrated lipid bilayers. Biophys J. 1988 Aug;54(2):259–267. doi: 10.1016/S0006-3495(88)82955-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Masotti L., Spisni A., Urry D. W. Conformational studies on the gramicidin A transmembrane channel in lipid micelles and liposomes. Cell Biophys. 1980 Sep;2(3):241–251. doi: 10.1007/BF02790452. [DOI] [PubMed] [Google Scholar]
  11. Mazet J. L., Andersen O. S., Koeppe R. E., 2nd Single-channel studies on linear gramicidins with altered amino acid sequences. A comparison of phenylalanine, tryptophane, and tyrosine substitutions at positions 1 and 11. Biophys J. 1984 Jan;45(1):263–276. doi: 10.1016/S0006-3495(84)84153-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Prasad K. U., Trapane T. L., Busath D., Szabo G., Urry D. W. Synthesis and characterization of (1-13C) Phe9 gramicidin A. Effects of side chain variations. Int J Pept Protein Res. 1983 Sep;22(3):341–347. doi: 10.1111/j.1399-3011.1983.tb02100.x. [DOI] [PubMed] [Google Scholar]
  13. Sawyer D. B., Koeppe R. E., 2nd, Andersen O. S. Gramicidin single-channel properties show no solvent-history dependence. Biophys J. 1990 Mar;57(3):515–523. doi: 10.1016/S0006-3495(90)82567-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Sawyer D. B., Koeppe R. E., 2nd, Andersen O. S. Induction of conductance heterogeneity in gramicidin channels. Biochemistry. 1989 Aug 8;28(16):6571–6583. doi: 10.1021/bi00442a007. [DOI] [PubMed] [Google Scholar]
  15. Urry D. W., Long M. M., Jacobs M., Harris R. D. Conformation and molecular mechanisms of carriers and channels. Ann N Y Acad Sci. 1975 Dec 30;264:203–220. doi: 10.1111/j.1749-6632.1975.tb31484.x. [DOI] [PubMed] [Google Scholar]
  16. Urry D. W., Spisni A., Khaled A. Characterization of micellar-packaged gramicidin A channels. Biochem Biophys Res Commun. 1979 Jun 13;88(3):940–949. doi: 10.1016/0006-291x(79)91499-2. [DOI] [PubMed] [Google Scholar]
  17. Veatch W., Stryer L. The dimeric nature of the gramicidin A transmembrane channel: conductance and fluorescence energy transfer studies of hybrid channels. J Mol Biol. 1977 Jun 15;113(1):89–102. doi: 10.1016/0022-2836(77)90042-0. [DOI] [PubMed] [Google Scholar]

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