Preresonance Raman spectroscopic studies on retinoid binding proteins: RBP, CRBP-I and CRALBP.
Item
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Title
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Preresonance Raman spectroscopic studies on retinoid binding proteins: RBP, CRBP-I and CRALBP.
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Identifier
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AAI9720101
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identifier
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9720101
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Creator
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Ju, Zhongmo.
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Contributor
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Adviser: Robert H. Callender
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Date
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1997
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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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Physics, Molecular | Biophysics, General
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Abstract
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The nature of the binding interactions between retinoid and many retinoid binding proteins is not well understood. Three such proteins: Retinol Binding Protein (RBP), Cellular Retinol Binding Protein-I (CRBP-I) and Cellular Retinaldehyde Bingding Protein (CRALBP) have been isolated, complexed with all-trans and 11-cis retinal respectively, and probed using pre-resonance and difference Raman spectroscopy.;In the study of RBP, we have measured the pre-presonance Raman spectra of retinal, retinoic acid and retinol in dilute CCl{dollar}\sb4{dollar} solutions and when bound to bovine-serum RBP. The comparison reveals that the binding interaction does not involve any specific interactions of the terminal group and the polyene chain with a particular protein residue. The data indicate hydrogen bonding of bound retinal's head group oxygen to water, as well as some torsional angle change of its polyene chain upon binding.;The pre-resonance Raman spectrum of all-trans retinal complexed with CRBP-I has also been obtained, displaying a spectral shift in the position of the retinal carbonyl band that is typical of hydrogen bonding effects. This carbonyl red shift has been compared to hydrogen bonding interactions between the all-trans retinal carbonyl and a series of phenol derivatives, varying in proton donating ability by FT-IR spectroscopy, allowing quantitation of the hydrogen bond enthalpy.;To characterize the bonding between CRALBP and the carbonyl of 11-cis retinal, a difference Raman experiment was performed using protein complexes with native 11-cis retinal and 11-cis retinal isotopically labeled with {dollar}\sp{13}{dollar}C at the 15 position. The difference spectrum has been compared to solution Raman spectra of 11-cis retinaldehyde, Schiff Base and Protonated Schiff Base in order to evaluate the retinoid CRALBP link. The results point to a possibility either Schiff Base or H-bond as the linkage between CRALBP and 11-cis retinal. Future isotopic labeling study of CRALBP complexed with {dollar}\sp{18}{dollar}O-edited 11-cis retinal is designed to clarify this confusion.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
