Source:http://linkedlifedata.com/resource/pubmed/id/15895435
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|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
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| pubmed:dateCreated |
2005-11-10
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| pubmed:abstractText |
The incporation of beta-amino acid residues into the strand segments of designed beta-hairpin leads to the formation of polar sheets, since in the case of beta-peptide strands, all adjacent carbonyl groups point in one direction and the amide groups orient in the opposite direction. The conformational analysis of two designed peptide hairpins composed of alpha/beta-hybrid segments are described: Boc-Leu-betaPhe-Val-(D)-Pro-Gly-Leu-betaPhe-Val-OMe (1) and Boc-betaLeu-Phe-betaVal-D-Pro-Gly-betaLeu-Phe-betaVal-OMe (2). A 500-MHz 1H-NMR (nuclear magnetic resonance) analysis in methanol supports a significant population of hairpin conformations in both peptides. Diagnostic nuclear Overhauser effects (NOEs) are observed in both cases. X-ray diffraction studies on single crystals of peptide 1 reveal a beta-hairpin conformation in both the molecules, which constitute the crystallographic asymmetric unit. Three cross-strand hydrogen bonds and a nucleating type II' beta-turn at the D-Pro-Gly segment are observed in the two independent molecules. In peptide 1, the betaPhe residues at positions 2 and 7 occur at the nonhydrogen-bonding position, with the benzyl side chains pointing on opposite faces of the beta-sheet. The observed aromatic centroid-to-centroid distances are 8.92 A (molecule A) and 8.94 A (molecule B). In peptide 2, the aromatic rings must occupy facing positions in antiparallel strands, in the NMR-derived structure. Peptide 1 yields a normal "hairpin-like" CD spectrum in methanol with a minimum at 224 nm. The CD spectrum of peptide 2 reveals a negative band at 234 nm and a positive band at 221 nm, suggestive of an exciton split doublet. Modeling of the facing Phe side chains at the hydrogen-bonding position of a canonical beta-hairpin suggests that interring separation is approximately 4.78 A for the gauche+ gauche- (g+ g-) rotamer. A previously reported peptide beta-hairpin composed of only alpha-amino acids, Boc-Leu-Phe-Val-D-Pro-Gly-Leu-Phe-Val-OMe also exhibited an anomalous far-UV (ultraviolet) CD (circular dichroism) spectrum, which was interpreted in terms of interactions between facing aromatic chromophores, Phe 2 and Phe 7 (C. Zhao, P. L. Polavarapu, C. Das, and P. Balaram, Journal of the American Chemical Society, 2000, Vol 122, pp. 8228-8231).
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| pubmed:grant | |
| pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-10725396,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11169393,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11259666,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11389934,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11710065,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11880601,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-11982362,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-12207544,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-12211030,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-12211031,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-12470725,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-12720442,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-14967024,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-2023252,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-3892686,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-7488115,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-8673604,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-8710845,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-9827995,
http://linkedlifedata.com/resource/pubmed/commentcorrection/15895435-9914187
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:issn |
0006-3525
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| pubmed:author | |
| pubmed:copyrightInfo |
Copyright 2005 Wiley Periodicals, Inc.
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| pubmed:issnType |
Print
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| pubmed:volume |
80
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
787-99
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| pubmed:dateRevised |
2009-11-18
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| pubmed:meshHeading |
pubmed-meshheading:15895435-Amino Acid Sequence,
pubmed-meshheading:15895435-Amino Acids,
pubmed-meshheading:15895435-Chromatography, High Pressure Liquid,
pubmed-meshheading:15895435-Circular Dichroism,
pubmed-meshheading:15895435-Crystallography, X-Ray,
pubmed-meshheading:15895435-Hydrogen Bonding,
pubmed-meshheading:15895435-Models, Chemical,
pubmed-meshheading:15895435-Models, Molecular,
pubmed-meshheading:15895435-Molecular Conformation,
pubmed-meshheading:15895435-Molecular Weight,
pubmed-meshheading:15895435-Nuclear Magnetic Resonance, Biomolecular,
pubmed-meshheading:15895435-Oligopeptides,
pubmed-meshheading:15895435-Phenylalanine,
pubmed-meshheading:15895435-Protein Binding,
pubmed-meshheading:15895435-Protein Conformation,
pubmed-meshheading:15895435-Protein Structure, Secondary,
pubmed-meshheading:15895435-Spectrometry, Mass, Electrospray Ionization,
pubmed-meshheading:15895435-Stereoisomerism,
pubmed-meshheading:15895435-X-Ray Diffraction
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| pubmed:year |
2005
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| pubmed:articleTitle |
Peptide hairpins with strand segments containing alpha- and beta-amino acid residues: cross-strand aromatic interactions of facing Phe residues.
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| pubmed:affiliation |
Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India.
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| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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