| Oligomeric cholates: amphiphilic foldamers with nanometer-sized hydrophilic cavities. | |
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MedLine Citation:
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PMID: 16351121 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The hydroxyl at the C-3 of cholic acid was converted to an amino group, and the resulting amino-functionalized cholic acid was used as a monomer to prepare amide-linked oligomeric cholates. These cholate oligomers fold into helical structures with nanometer-sized hydrophilic internal cavities in solvent mixtures consisting of mostly nonpolar solvents such as carbon tetrachloride or ethyl acetate/hexane and 2-5% of a polar solvent such as methanol or DMSO. The conformations of the foldamers were studied by UV, fluorescence, fluorescence quenching, and fluorescence resonance energy transfer. The nature of the polar/nonpolar solvents and their miscibility strongly influenced the folding reaction. Folding was cooperative, as evidenced by the sigmoidal curves in solvent denaturation experiments. The folded conformers became more stable with an increase in the chain length. The folding/unfolding equilibrium was highly sensitive toward the amount of polar solvent. One percent variation in the solvent composition could change the folding free energies by 0.5-1.4 kcal/mol. |
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Authors:
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Yan Zhao; Zhenqi Zhong |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of the American Chemical Society Volume: 127 ISSN: 0002-7863 ISO Abbreviation: J. Am. Chem. Soc. Publication Date: 2005 Dec |
Date Detail:
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Created Date: 2005-12-14 Completed Date: 2006-03-07 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7503056 Medline TA: J Am Chem Soc Country: United States |
Other Details:
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Languages: eng Pagination: 17894-901 Citation Subset: IM |
Affiliation:
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Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111, USA. zhaoy@iastate.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Amides
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chemistry Cholates / chemical synthesis, chemistry* Fluorescence Resonance Energy Transfer Molecular Conformation Nanostructures / chemistry* Spectrometry, Fluorescence Spectrophotometry, Ultraviolet |
| Chemical | |
Reg. No./Substance:
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0/Amides; 0/Cholates |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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