Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/1064
Type: Artigo de periódico
Title: Gaining ligand selectivity in thyroid hormone receptors via entropy
Author: MARTINEZ, Leandro
NASCIMENTO, Alessandro S.
NUNES, Fabio M.
PHILLIPS, Kevin
APARICIO, Ricardo
DIAS, Sandra Martha G.
FIGUEIRA, Ana Carolina M.
LIN, Jean H.
NGUYEN, Phuong
APRILETTI, James W.
NEVES, Francisco A. R.
BAXTER, John D.
WEBB, Paul
SKAF, Munir S.
POLIKARPOV, Igor
Abstract: Nuclear receptors are important targets for pharmaceuticals, but similarities between family members cause difficulties in obtaining highly selective compounds. Synthetic ligands that are selective for thyroid hormone (TH) receptor beta (TR beta) vs. TR alpha reduce cholesterol and fat without effects on heart rate; thus, it is important to understand TR beta-selective binding. Binding of 3 selective ligands (GC-1, KB141, and GC-24) is characterized at the atomic level; preferential binding depends on a nonconserved residue (Asn-331 beta) in the TR beta ligand-binding cavity (LBC), and GC-24 gains extra selectivity from insertion of a bulky side group into an extension of the LBC that only opens up with this ligand. Here we report that the natural TH 3,5,3`-triodothyroacetic acid (Triac) exhibits a previously unrecognized mechanism of TR beta selectivity. TR x-ray structures reveal better fit of ligand with the TR alpha LBC. The TR beta LBC, however, expands relative to TR alpha in the presence of Triac (549 angstrom(3) vs. 461 angstrom(3)), and molecular dynamics simulations reveal that water occupies the extra space. Increased solvation compensates for weaker interactions of ligand with TR beta and permits greater flexibility of the Triac carboxylate group in TR beta than in TR alpha. We propose that this effect results in lower entropic restraint and decreases free energy of interactions between Triac and TR beta, explaining subtype-selective binding. Similar effects could potentially be exploited in nuclear receptor drug design.
Subject: Triac
design
mobility
Country: Estados Unidos
Editor: NATL ACAD SCIENCES
Citation: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, v.106, n.49, p.20717-20722, 2009
Rights: fechado
Identifier DOI: 10.1073/pnas.0911024106
Address: http://apps.isiknowledge.com/InboundService.do?Func=Frame&product=WOS&action=retrieve&SrcApp=EndNote&UT=000272553000032&Init=Yes&SrcAuth=ResearchSoft&mode=FullRecord
http://dx.doi.org/10.1073/pnas.0911024106
Date Issue: 2009
Appears in Collections:IQ - Artigos e Materiais de Revistas Científicas

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