Molecular interactions of adipocyte fatty acid-binding protein with activating and non-activating ligands: Protein oligomerization and ligand binding sites
Item
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Title
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Molecular interactions of adipocyte fatty acid-binding protein with activating and non-activating ligands: Protein oligomerization and ligand binding sites
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Identifier
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d_2009_2013:5e214c964415:12047
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identifier
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12732
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Creator
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Rizk, Samar Helmy,
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Contributor
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Ruth E. Stark
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Date
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2013
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biochemistry
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Abstract
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Intracellular lipid binding proteins involved in fatty acid transport and metabolism include adipocyte fatty acid-binding protein (AFABP), a 15 kDa polypeptide that plays a central role in the development of diabetes and atherosclerotic cardiovascular disease in experimental animals; the significant degree to which the protein is released into the bloodstream is thought to predict the development of Metabolic Syndrome. Upon binding of activating ligands such as linoleate and troglitazone (TDZ) or inactivating ligands such as oleate, AFABP has been proposed to adopt two alternative modes of self-association that activate or deactivate a nuclear localization signal. The goal of this study is to develop a molecular rationale for these contrasting ligand-associated signals. Both apo and liganded AFABP proteins were shown to maintain an overwhelmingly monomeric form in solution using size exclusion chromatography and static light scattering methods. Multidimensional solution-state nuclear magnetic resonance experiments were used to make sequential resonance assignments of the polypeptide backbone 1H and 15N nuclei. These assignments made possible ligand titration experiments that identified the key protein residues involved in the binding and the defined binding site. Comparative analysis of the binding sites in the three holo proteins demonstrated that oleate and linoleate bind similarly in a U-shaped configuration within the protein binding cavity despite their contrasting functional behavior, whereas the activating linoleate and TDZ ligands bind at dissimilar sites with the AFABP protein.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Biochemistry
