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

J. Biol. Chem., Vol. 275, Issue 25, 18818-18823, June 23, 2000

This Article Full Text Full Text (PDF) All Versions of this Article: 275/25/18818    most recent M000193200v1 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 Hang, J. Articles by Xue, H. Search for Related Content PubMed PubMed Citation Articles by Hang, J. Articles by Xue, H. Social Bookmarking                      What's this?

Ligand Binding and Structural Properties of Segments of GABA_A Receptor ₁ Subunit Overexpressed in Escherichia coli^*

Jun Hang, Haifeng Shi, Dongyang Li, Yinglei Liao, Dejun Lian, Yazhong Xiao, and Hong Xue

From the Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong

The -aminobutyric acid, type A (GABA_A), receptor is the target for numerous therapeutic compounds. In the present study, the Gln²⁸-Leu²⁹⁶, Gln²⁸-Arg²⁷⁶, Gln²⁸-Arg²⁴⁸, and Gln²⁸-Glu¹⁶⁵ (numbering of bovine precursor protein) segments of its ₁ subunit were overexpressed in Escherichia coli, along with Cys¹⁶⁶-Leu²⁹⁶ produced previously, for structural analysis by circular dichroism and ligand binding studies by fluorescence spectroscopy. Results showed that the protein segments were rich in -sheet structures. Binding of the fluorescent benzodiazepine Bodipy-FL Ro-1986 was evident from fluorescence resonance energy transfer and fluorescence anisotropy measurements. The binding affinity was in the micromolar range. The binding was attributable more to Cys¹⁶⁶-Leu²⁹⁶ than to Gln²⁸-Glu¹⁶⁵ and was inhibited by known central benzodiazepine site ligands. Three point mutations, Y187A, T234A, and Y237A, were found to perturb protein secondary structures. Studies with the single Trp mutants W198Y and W273Y indicated that Trp²⁷³ was closer to the binding site than Trp¹⁹⁸.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				S.-Y. Tsang, S.-K. Ng, Z. Xu, and H. Xue The Evolution of GABAA Receptor-Like Genes Mol. Biol. Evol., February 1, 2007; 24(2): 599 - 610. [Abstract] [Full Text] [PDF]