1bdk
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(New page: 200px<br /><applet load="1bdk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bdk" /> '''AN NMR, CD, MOLECULAR DYNAMICS, AND FLUOROME...)
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Revision as of 21:55, 24 November 2007
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AN NMR, CD, MOLECULAR DYNAMICS, AND FLUOROMETRIC STUDY OF THE CONFORMATION OF THE BRADYKININ ANTAGONIST B-9340 IN WATER AND IN AQUEOUS MICELLAR SOLUTIONS
Overview
A detailed NMR, CD, fluorometry, and molecular modeling study of a novel, bradykinin antagonist B-9340, containing a novel amino acid D-Igl, (alpha-(2-indanyl)glycine) at position 7, was carried out. The sequence of, B-9340 is D-Arg0-Arg1-Pro2-Hyp3-Gly4-Thi5-Ser6-D- Igl7-Oic8-Arg9, where, Hyp is hydroxyproline, Thi is beta-(2-thienyl)alanine, and Oic is, (3aS,7aS)-octahydroindole-2-carboxylic acid. The CD results exhibit a, striking effect of SDS on the spectrum of the BK antagonist, indicating, that interaction with the surfactant induces a folded peptide structure., The interaction of this antagonist with phosphatidylinositol was monitored, by fluorometry, indicating that the interaction of the peptide with the, lipid is cooperative, and gives a Hill coefficient of 2.3. The, two-dimensional proton NMR measurements indicate that B-9340 has no stable, secondary structure in water solution and contains about 10-15% cis, peptide bonds arising from Pro2, Hyp3, and Oic8. In SDS micelles, NMR, reveals the existence of two beta-turns based on a number of medium-range, connectivities that were useful for molecular modeling. The actual, molecular modeling and dynamic runs were performed on B-9340 in an, environment consisting of a layer of octyl sulfate anions and water. Ther, results indicate that the structure of B-9340 in a micellar environment is, characterized by a nonideal betaII-turn comprising residues Pro2 to Thi5, a nonideal betaII'-turn comprising residues Ser6-Arg9, and broad folding, in the middle part of the molecule. The structure is stabilized by several, hydrogen bonds and by a salt bridge between the guanidine moiety of Arg1, and the carboxyl group of Arg9, whereas the middle part of the peptide is, buried in the micelle. The structure is deposited as Brookhaven PDB file 1, BDK.
About this Structure
1BDK is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
An NMR, CD, molecular dynamics, and fluorometric study of the conformation of the bradykinin antagonist B-9340 in water and in aqueous micellar solutions., Sejbal J, Cann JR, Stewart JM, Gera L, Kotovych G, J Med Chem. 1996 Mar 15;39(6):1281-92. PMID:8632435
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