MolPharm xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Marjamäki, A.
Right arrow Articles by Scheinin, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marjamäki, A.
Right arrow Articles by Scheinin, M.

Vol. 53, Issue 3, 370-376, March 1998

Chloroethylclonidine Binds Irreversibly to Exposed Cysteines in the Fifth Membrane-Spanning Domain of the Human alpha 2A-Adrenergic Receptor

Anne Marjamäki, Marjo Pihlavisto, Victor Cockcroft,1 Petri Heinonen, Juha-Matti Savola,1 and Mika Scheinin

Departments of Pharmacology and Clinical Pharmacology (A.M., M.P., M.S.) and Chemistry (P.H.), University of Turku, FIN-20500, Turku, Finland, and Orion Corporation (V.C., J.-M.S.), Orion-Pharma, FIN-20101, Turku, Finland

The alpha 2-adrenergic receptors (alpha 2-ARs) mediate signals to intracellular second messengers via guanine nucleotide binding proteins. Three human genes encoding alpha 2-AR subtypes (alpha 2A, alpha 2B, alpha 2C) have been cloned. Several chemical compounds display subtype differences in their binding and/or functional activity. Site-directed mutagenesis and molecular modeling are new tools with which to investigate the subtype selectivity of ligands. In this study, we introduce a new approach to mapping of the binding site crevice of the human alpha 2A-AR. Based on a three-dimensional receptor model, we systematically mutated residues 197-201 and 204 in the fifth transmembrane domain of the human alpha 2A-AR to cysteine. Chloroethylclonidine, an alkylating derivative of the alpha 2-adrenergic agonist clonidine, binds irreversibly to alpha 2A-ARs by forming a covalent bond with the sulfhydryl side chain of a cysteine residue exposed in the binding cavity, leading to inactivation of the receptor. Irreversible binding of chloroethylclonidine was used as a criterion for identifying introduced cysteine residues as being exposed in the binding cavity. The results supported a receptor model in which the fifth transmembrane domain is alpha -helical, with residues Val197, Ser200, Cys201, and Ser204 exposed in the binding pocket. Residues Ile198, Ser199, Ile202, and Gly203 face the lipid bilayer of the plasma membrane. This approach emerges as a powerful tool for structural characterization of the alpha 2-ARs.

Copyright © 1998 by The American Society for Pharmacology and Experimental Therapeutics


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
C. Tahtaoui, M.-N. Balestre, P. Klotz, D. Rognan, C. Barberis, B. Mouillac, and M. Hibert
Identification of the Binding Sites of the SR49059 Nonpeptide Antagonist into the V1a Vasopressin Receptor Using Sulfydryl-reactive Ligands and Cysteine Mutants as Chemical Sensors
J. Biol. Chem., October 10, 2003; 278(41): 40010 - 40019.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
T. Nyrönen, M. Pihlavisto, J. M. Peltonen, A.-M. Hoffrén, M. Varis, T. Salminen, S. Wurster, A. Marjamäki, L. Kanerva, E. Katainen, et al.
Molecular Mechanism for Agonist-Promoted alpha 2A-Adrenoceptor Activation by Norepinephrine and Epinephrine
Mol. Pharmacol., April 16, 2001; 59(5): 1343 - 1354.
[Abstract] [Full Text]

Home page
 Protein Eng Des SelHome page
C. M. Topham, L. Mouledous, and J.-C. Meunier
On the spatial disposition of the fifth transmembrane helix and the structural integrity of the transmembrane binding site in the opioid and ORL1 G protein-coupled receptor family
Protein Eng. Des. Sel., July 1, 2000; 13(7): 477 - 490.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
K. Allman, K. M. Page, C. A.M. Curtis, and E. C. Hulme
Scanning Mutagenesis Identifies Amino Acid Side Chains in Transmembrane Domain 5 of the M1 Muscarinic Receptor that Participate in Binding the Acetyl Methyl Group of Acetylcholine
Mol. Pharmacol., July 1, 2000; 58(1): 175 - 184.
[Abstract] [Full Text]

Home page
 J. Biol. Chem.Home page
T. Salminen, M. Varis, T. Nyronen, M. Pihlavisto, A.-M. Hoffren, T. Lonnberg, A. Marjamaki, H. Frang, J.-M. Savola, M. Scheinin, et al.
Three-dimensional Models of alpha 2A-Adrenergic Receptor Complexes Provide a Structural Explanation for Ligand Binding
J. Biol. Chem., August 13, 1999; 274(33): 23405 - 23413.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
A. Marjamaki, H. Frang, M. Pihlavisto, A.-M. Hoffren, T. Salminen, M. S. Johnson, J. Kallio, J. A. Javitch, and M. Scheinin
Chloroethylclonidine and 2-Aminoethyl Methanethiosulfonate Recognize Two Different Conformations of the Human alpha 2A-Adrenergic Receptor
J. Biol. Chem., July 30, 1999; 274(31): 21867 - 21872.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
H. Frang, V. Cockcroft, T. Karskela, M. Scheinin, and A. Marjamaki
Phenoxybenzamine Binding Reveals the Helical Orientation of the Third Transmembrane Domain of Adrenergic Receptors
J. Biol. Chem., August 10, 2001; 276(33): 31279 - 31284.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1998 by the American Society for Pharmacology and Experimental Therapeutics