HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Reddy, G. L. Articles by Montal, M. Search for Related Content PubMed PubMed Citation Articles by Reddy, G. L. Articles by Montal, M. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 268, Issue 20, 14608-14615, 07, 1993

Synthetic peptides and four-helix bundle proteins as model systems for the pore-forming structure of channel proteins. II. Transmembrane segment M2 of the brain glycine receptor is a plausible candidate for the pore-lining structure

GL Reddy, T Iwamoto, JM Tomich and M Montal
Department of Biology, University of California, San Diego, La Jolla 92093-0319.

A synthetic 23-mer peptide (M2GlyR) with the amino acid sequence of the putative transmembrane segment M2 of the strychnine-binding alpha subunit of the inhibitory glycine receptor forms anion-selective channels in phospholipid bilayers. The most frequent events show single- channel conductances, gamma, of 25 pS and 49 pS in symmetric 0.5 M KCl with channel open lifetimes, tau o, in the millisecond time range. These properties match those of authentic glycine receptors studied in inside-out patches of cultured rat spinal cord neurons, namely gamma = 27 pS and gamma = 45 pS, and tau o in the millisecond time range. The channel activity of M2GlyR is sequence-specific: 1) a synthetic peptide with the sequence of putative transmembrane segment M1 (M1GlyR), not considered to contribute to the channel lining, does not form channels; 2) an analog of M2GlyR with site-specific substitutions displays distinct channel properties: 2 arginine residues at the N and C termini of M2, postulated to contribute to the anion selectivity of the channel, are substituted by glutamic acids, and the analog peptide ([Glu3,22]M2GlyR) forms cation-selective channels. Further, a four- helix bundle protein (T4M2GlyR) formed by tethering four identical M2GlyR modules to a carrier template forms homogeneous anion-selective channels with gamma = 25 pS in 0.5 M KCl. These channels are blocked by picrotoxin and by the anion channel blockers 9-anthracene carboxylic acid and niflumic acid, but not by an analog of the local anesthetic lidocaine (QX-222), a cation channel blocker. Observed single-channel properties suggest that a pentameric assembly of alpha and beta subunits with a central pore lined by M2 segments would account for conductance properties of the authentic glycine receptor and the 2 arginines at either end of M2 could confer anion specificity to the receptor channel.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				F. W. van Ginkel, T. Iwamoto, B. D. Schultz, and J. M. Tomich Immunity to a Self-Derived, Channel-Forming Peptide in the Respiratory Tract Clin. Vaccine Immunol., February 1, 2008; 15(2): 260 - 266. [Abstract] [Full Text] [PDF]

				J. Hu, H. Qin, C. Li, M. Sharma, T. A. Cross, and F. P. Gao Structural biology of transmembrane domains: Efficient production and characterization of transmembrane peptides by NMR Protein Sci., October 1, 2007; 16(10): 2153 - 2165. [Abstract] [Full Text] [PDF]

				J. M. Johnston, G. A. Cook, J. M. Tomich, and M. S. P. Sansom Conformation and Environment of Channel-Forming Peptides: A Simulation Study Biophys. J., March 15, 2006; 90(6): 1855 - 1864. [Abstract] [Full Text] [PDF]

				L. P. Shank, J. R. Broughman, W. Takeguchi, G. Cook, A. S. Robbins, L. Hahn, G. Radke, T. Iwamoto, B. D. Schultz, and J. M. Tomich Redesigning Channel-Forming Peptides: Amino Acid Substitutions that Enhance Rates of Supramolecular Self-Assembly and Raise Ion Transport Activity Biophys. J., March 15, 2006; 90(6): 2138 - 2150. [Abstract] [Full Text] [PDF]

				H. Qian, Y. Pan, Y. Zhu, and P. Khalili Picrotoxin Accelerates Relaxation of GABAC Receptors Mol. Pharmacol., February 1, 2005; 67(2): 470 - 479. [Abstract] [Full Text] [PDF]

				J. R. Broughman, R. M. Brandt, C. Hastings, T. Iwamoto, J. M. Tomich, and B. D. Schultz Channel-forming peptide modulates transepithelial electrical conductance and solute permeability Am J Physiol Cell Physiol, June 1, 2004; 286(6): C1312 - C1323. [Abstract] [Full Text] [PDF]

				C. F. W. Becker, M. Oblatt-Montal, G. G. Kochendoerfer, and M. Montal Chemical Synthesis and Single Channel Properties of Tetrameric and Pentameric TASPs (Template-assembled Synthetic Proteins) Derived from the Transmembrane Domain of HIV Virus Protein u (Vpu) J. Biol. Chem., April 23, 2004; 279(17): 17483 - 17489. [Abstract] [Full Text] [PDF]

				K.-H. Park, C. Berrier, B. Martinac, and A. Ghazi Purification and Functional Reconstitution of N- and C-Halves of the MscL Channel Biophys. J., April 1, 2004; 86(4): 2129 - 2136. [Abstract] [Full Text] [PDF]

				G. A. Cook, O. Prakash, K. Zhang, L. P. Shank, W. A. Takeguchi, A. Robbins, Y.-X. Gong, T. Iwamoto, B. D. Schultz, and J. M. Tomich Activity and Structural Comparisons of Solution Associating and Monomeric Channel-Forming Peptides Derived from the Glycine Receptor M2 Segment Biophys. J., March 1, 2004; 86(3): 1424 - 1435. [Abstract] [Full Text] [PDF]

				P. Tang, P. K. Mandal, and Y. Xu NMR Structures of the Second Transmembrane Domain of the Human Glycine Receptor alpha 1 Subunit: Model of Pore Architecture and Channel Gating Biophys. J., July 1, 2002; 83(1): 252 - 262. [Abstract] [Full Text] [PDF]

				M. I. Dibas, E. B. Gonzales, P. Das, C. L. Bell-Horner, and G. H. Dillon Identification of a Novel Residue within the Second Transmembrane Domain That Confers Use-facilitated Block by Picrotoxin in Glycine alpha 1 Receptors J. Biol. Chem., March 8, 2002; 277(11): 9112 - 9117. [Abstract] [Full Text] [PDF]

				L. Gao, J. R. Broughman, T. Iwamoto, J. M. Tomich, C. J. Venglarik, and H. J. Forman Synthetic chloride channel restores glutathione secretion in cystic fibrosis airway epithelia Am J Physiol Lung Cell Mol Physiol, July 1, 2001; 281(1): L24 - L30. [Abstract] [Full Text] [PDF]

				J. R. Broughman, K. E. Mitchell, R. L. Sedlacek, T. Iwamoto, J. M. Tomich, and B. D. Schultz NH2-terminal modification of a channel-forming peptide increases capacity for epithelial anion secretion Am J Physiol Cell Physiol, March 1, 2001; 280(3): C451 - C458. [Abstract] [Full Text] [PDF]

				D. C. DAWSON, S. S. SMITH, and M. K. MANSOURA CFTR: Mechanism of Anion Conduction Physiol Rev, January 1, 1999; 79(1): 47 - 75. [Abstract] [Full Text] [PDF]

				S. L. Schendel, Z. Xie, M. O. Montal, S. Matsuyama, M. Montal, and J. C. Reed Channel formation by antiapoptotic protein Bcl-2 PNAS, May 13, 1997; 94(10): 5113 - 5118. [Abstract] [Full Text] [PDF]