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

J. Biol. Chem., Vol. 281, Issue 39, 29256-29267, September 29, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/39/29256    most recent M603018200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bourne, Y. Articles by Marchot, P. Search for Related Content PubMed PubMed Citation Articles by Bourne, Y. Articles by Marchot, P. Social Bookmarking                      What's this?

Substrate and Product Trafficking through the Active Center Gorge of Acetylcholinesterase Analyzed by Crystallography and Equilibrium Binding^*

Yves Bourne¹, Zoran Radi, Gerlind Sulzenbacher, Esther Kim, Palmer Taylor, and Pascale Marchot^¶2

From the ^¶Ingénierie des Protéines, CNRS FRE-2738, Institut Fédératif de Recherche Jean Roche, UniversitédelaMéditerranée, FacultédeMédecine Secteur Nord, F-13916 Marseille Cedex 20, France, the Architecture et Fonction des Macromolécules Biologiques, CNRS UMR-6098, Campus Luminy, Case 932, F-13288 Marseille Cedex 09, France, and the Department of Pharmacology, University of California at San Diego, La Jolla, California 92093-0636

Hydrolysis of acetylcholine catalyzed by acetylcholinesterase (AChE), one of the most efficient enzymes in nature, occurs at the base of a deep and narrow active center gorge. At the entrance of the gorge, the peripheral anionic site provides a binding locus for allosteric ligands, including substrates. To date, no structural information on substrate entry to the active center from the peripheral site of AChE or its subsequent egress has been reported. Complementary crystal structures of mouse AChE and an inactive mouse AChE mutant with a substituted catalytic serine (S203A), in various complexes with four substrates (acetylcholine, acetylthiocholine, succinyldicholine, and butyrylthiocholine), two non-hydrolyzable substrate analogues (m-(N,N,N-trimethylammonio)-trifluoroacetophenone and 4-ketoamyltrimethylammonium), and one reaction product (choline) were solved in the 2.05-2.65-Å resolution range. These structures, supported by binding and inhibition data obtained on the same complexes, reveal the successive positions and orientations of the substrates bound to the peripheral site and proceeding within the gorge toward the active site, the conformations of the presumed transition state for acylation and the acyl-enzyme intermediate, and the positions and orientations of the dissociating and egressing products. Moreover, the structures of the AChE mutant in complexes with acetylthiocholine and succinyldicholine reveal additional substrate binding sites on the enzyme surface, distal to the gorge entry. Hence, we provide a comprehensive set of structural snapshots of the steps leading to the intermediates of catalysis and the potential regulation by substrate binding to various allosteric sites at the enzyme surface.

Received for publication, March 30, 2006 , and in revised form, July 5, 2006.

The atomic coordinates and structure factors (codes 2H9Y, 2HA0, 2HA2, 2HA3, 2HA4, 2HA5, 2HA6, and 2HA7) have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ (http://www.rcsb.org/).

^* This work was supported by United States Public Health Service Grant R37-GM18360 and Department of Army Medical Defense Grant 17-1-8014 (to P. T.) and the Association Française contre les Myopathies (to P. M.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence may be addressed. Tel.: 33-491-825-566; Fax: 33-491-266-720; E-mail: Yves.Bourne{at}afmb.univ-mrs.fr.

² To whom correspondence may be addressed. Tel.: 33-491-698-908; Fax: 33-491-657-595; E-mail: marchot.p{at}jean-roche.univ-mrs.fr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J.-P. Colletier, D. Bourgeois, B. Sanson, D. Fournier, J. L. Sussman, I. Silman, and M. Weik Shoot-and-Trap: Use of specific x-ray damage to study structural protein dynamics by temperature-controlled cryo-crystallography PNAS, August 19, 2008; 105(33): 11742 - 11747. [Abstract] [Full Text] [PDF]

				L. G. Sultatos Concentration-Dependent Binding of Chlorpyrifos Oxon to Acetylcholinesterase Toxicol. Sci., November 1, 2007; 100(1): 128 - 135. [Abstract] [Full Text] [PDF]