Abstract
There is a distinct possibility that general anesthetics exert their action on the postsynaptic receptor channels. The structural requirements for anesthetic binding in transmembrane channels, however, are largely unknown. High-resolution (1)H nuclear magnetic resonance and direct photoaffinity labeling were used in this study to characterize the volatile anesthetic binding sites in gramicidin A (gA) incorporated into sodium dodecyl sulfate (SDS) micelles and into dimyristoylphosphatidylcholine (DMPC) bilayers, respectively. To confirm that the structural arrangement of the peptide side chains can affect anesthetic binding, gA in nonchannel forms in methanol was also analyzed. The addition of volatile anesthetic halothane to gA in SDS with a channel conformation caused a concentration-dependent change in resonant frequencies of the indole amide protons of W9, W11, W13, and W15, with the most profound changes in W9. These frequency changes were observed only for gA carefully prepared to ensure a channel conformation and were absent for gA in methanol. For gA in DMPC bilayers, direct [(14)C]halothane photolabeling and microsequencing demonstrated dominant labeling of W9, less labeling of W11 and W13, and no significant labeling of W15. In methanol, gA showed much less labeling of any residues. Inspection of the 3-D structure of gA suggests that the spatial arrangements of the tryptophan residues in the channel form of gA, combined with the amphiphilic regions of lipid, create a favorable anesthetic binding motif.
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- 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]
- Burkhart B. M., Gassman R. M., Langs D. A., Pangborn W. A., Duax W. L. Heterodimer formation and crystal nucleation of gramicidin D. Biophys J. 1998 Nov;75(5):2135–2146. doi: 10.1016/S0006-3495(98)77656-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cantor R. S. The lateral pressure profile in membranes: a physical mechanism of general anesthesia. Biochemistry. 1997 Mar 4;36(9):2339–2344. doi: 10.1021/bi9627323. [DOI] [PubMed] [Google Scholar]
- Chen Y., Wallace B. A. Binding of alkaline cations to the double-helical form of gramicidin. Biophys J. 1996 Jul;71(1):163–170. doi: 10.1016/S0006-3495(96)79213-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cotten M., Xu F., Cross T. A. Protein stability and conformational rearrangements in lipid bilayers: linear gramicidin, a model system. Biophys J. 1997 Aug;73(2):614–623. doi: 10.1016/S0006-3495(97)78097-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Cubero E., Luque F. J., Orozco M. Is polarization important in cation-pi interactions? Proc Natl Acad Sci U S A. 1998 May 26;95(11):5976–5980. doi: 10.1073/pnas.95.11.5976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dilger J. P., Boguslavsky R., Barann M., Katz T., Vidal A. M. Mechanisms of barbiturate inhibition of acetylcholine receptor channels. J Gen Physiol. 1997 Mar;109(3):401–414. doi: 10.1085/jgp.109.3.401. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eckenhoff R. G. Amino acid resolution of halothane binding sites in serum albumin. J Biol Chem. 1996 Jun 28;271(26):15521–15526. doi: 10.1074/jbc.271.26.15521. [DOI] [PubMed] [Google Scholar]
- Eckenhoff R. G., Johansson J. S. Molecular interactions between inhaled anesthetics and proteins. Pharmacol Rev. 1997 Dec;49(4):343–367. [PubMed] [Google Scholar]
- Forman S. A., Miller K. W., Yellen G. A discrete site for general anesthetics on a postsynaptic receptor. Mol Pharmacol. 1995 Oct;48(4):574–581. [PubMed] [Google Scholar]
- Franks N. P., Lieb W. R. Molecular and cellular mechanisms of general anaesthesia. Nature. 1994 Feb 17;367(6464):607–614. doi: 10.1038/367607a0. [DOI] [PubMed] [Google Scholar]
- Harrison N. L., Kugler J. L., Jones M. V., Greenblatt E. P., Pritchett D. B. Positive modulation of human gamma-aminobutyric acid type A and glycine receptors by the inhalation anesthetic isoflurane. Mol Pharmacol. 1993 Sep;44(3):628–632. [PubMed] [Google Scholar]
- Jenkins A., Franks N. P., Lieb W. R. Actions of general anaesthetics on 5-HT3 receptors in N1E-115 neuroblastoma cells. Br J Pharmacol. 1996 Apr;117(7):1507–1515. doi: 10.1111/j.1476-5381.1996.tb15314.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johansson J. S., Eckenhoff R. G. Minimum structural requirement for an inhalational anesthetic binding site on a protein target. Biochim Biophys Acta. 1996 May 21;1290(1):63–68. doi: 10.1016/0304-4165(95)00187-5. [DOI] [PubMed] [Google Scholar]
- Johansson J. S., Gibney B. R., Rabanal F., Reddy K. S., Dutton P. L. A designed cavity in the hydrophobic core of a four-alpha-helix bundle improves volatile anesthetic binding affinity. Biochemistry. 1998 Feb 3;37(5):1421–1429. doi: 10.1021/bi9721290. [DOI] [PubMed] [Google Scholar]
- Jude A. R., Greathouse D. V., Koeppe R. E., 2nd, Providence L. L., Andersen O. S. Modulation of gramicidin channel structure and function by the aliphatic "spacer" residues 10, 12, and 14 between the tryptophans. Biochemistry. 1999 Jan 19;38(3):1030–1039. doi: 10.1021/bi982043m. [DOI] [PubMed] [Google Scholar]
- Ketchem R. R., Hu W., Cross T. A. High-resolution conformation of gramicidin A in a lipid bilayer by solid-state NMR. Science. 1993 Sep 10;261(5127):1457–1460. doi: 10.1126/science.7690158. [DOI] [PubMed] [Google Scholar]
- Killian J. A. Gramicidin and gramicidin-lipid interactions. Biochim Biophys Acta. 1992 Dec 11;1113(3-4):391–425. doi: 10.1016/0304-4157(92)90008-x. [DOI] [PubMed] [Google Scholar]
- Laio A., Torre V. Physical origin of selectivity in ionic channels of biological membranes. Biophys J. 1999 Jan;76(1 Pt 1):129–148. doi: 10.1016/S0006-3495(99)77184-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Langs D. A., Smith G. D., Courseille C., Précigoux G., Hospital M. Monoclinic uncomplexed double-stranded, antiparallel, left-handed beta 5.6-helix (increases decreases beta 5.6) structure of gramicidin A: alternate patterns of helical association and deformation. Proc Natl Acad Sci U S A. 1991 Jun 15;88(12):5345–5349. doi: 10.1073/pnas.88.12.5345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lundbaek J. A., Andersen O. S. Spring constants for channel-induced lipid bilayer deformations. Estimates using gramicidin channels. Biophys J. 1999 Feb;76(2):889–895. doi: 10.1016/S0006-3495(99)77252-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mihic S. J., Ye Q., Wick M. J., Koltchine V. V., Krasowski M. D., Finn S. E., Mascia M. P., Valenzuela C. F., Hanson K. K., Greenblatt E. P. Sites of alcohol and volatile anaesthetic action on GABA(A) and glycine receptors. Nature. 1997 Sep 25;389(6649):385–389. doi: 10.1038/38738. [DOI] [PubMed] [Google Scholar]
- Piotto M., Saudek V., Sklenár V. Gradient-tailored excitation for single-quantum NMR spectroscopy of aqueous solutions. J Biomol NMR. 1992 Nov;2(6):661–665. doi: 10.1007/BF02192855. [DOI] [PubMed] [Google Scholar]
- Sayle R. A., Milner-White E. J. RASMOL: biomolecular graphics for all. Trends Biochem Sci. 1995 Sep;20(9):374–374. doi: 10.1016/s0968-0004(00)89080-5. [DOI] [PubMed] [Google Scholar]
- Tang P., Hu J., Liachenko S., Xu Y. Distinctly different interactions of anesthetic and nonimmobilizer with transmembrane channel peptides. Biophys J. 1999 Aug;77(2):739–746. doi: 10.1016/S0006-3495(99)76928-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tang P., Simplaceanu V., Xu Y. Structural consequences of anesthetic and nonimmobilizer interaction with gramicidin A channels. Biophys J. 1999 May;76(5):2346–2350. doi: 10.1016/S0006-3495(99)77391-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tang P., Yan B., Xu Y. Different distribution of fluorinated anesthetics and nonanesthetics in model membrane: a 19F NMR study. Biophys J. 1997 Apr;72(4):1676–1682. doi: 10.1016/S0006-3495(97)78813-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tian F., Cross T. A. Cation transport: an example of structural based selectivity. J Mol Biol. 1999 Feb 5;285(5):1993–2003. doi: 10.1006/jmbi.1998.2434. [DOI] [PubMed] [Google Scholar]
- Trudell J. R., Bertaccini E. Evaluation of forcefields for molecular mechanics/dynamics calculations involving halogenated anesthetics. Toxicol Lett. 1998 Nov 23;100-101:413–419. doi: 10.1016/s0378-4274(98)00215-x. [DOI] [PubMed] [Google Scholar]
- Veatch W. R., Fossel E. T., Blout E. R. The conformation of gramicidin A. Biochemistry. 1974 Dec 17;13(26):5249–5256. doi: 10.1021/bi00723a001. [DOI] [PubMed] [Google Scholar]
- Xu Y., Tang P. Amphiphilic sites for general anesthetic action? Evidence from 129Xe-[1H] intermolecular nuclear Overhauser effects. Biochim Biophys Acta. 1997 Jan 14;1323(1):154–162. doi: 10.1016/s0005-2736(96)00184-8. [DOI] [PubMed] [Google Scholar]
- Xu Y., Tang P., Liachenko S. Unifying characteristics of sites of anesthetic action revealed by combined use of anesthetics and non-anesthetics. Toxicol Lett. 1998 Nov 23;100-101:347–352. doi: 10.1016/s0378-4274(98)00205-7. [DOI] [PubMed] [Google Scholar]