Linked Life Data

1457725

Source:http://linkedlifedata.com/resource/pubmed/id/1457725

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1993-1-14
pubmed:abstractText
Previously calculated conformational energy maps suggest that the alpha-helical conformation for the residue preceding a proline is disfavored relative to the extended conformation by more than 7 kcal/mol. In known protein structures this conformation is observed, however, to occur for about 9% of all prolines. In addition, introduction or removal of prolines at theoretically unfavorable positions in proteins and peptides can have modest effects on stability and structure. To investigate the discrepancy between calculation and experiment, we have determined how the conformation of the proline affects the calculated energy. We have also explored the effect of bond length and bond angle relaxation on the conformational energy map. The conformational energy of the preceding residue is found to be unaffected by the conformation of the proline, but the effect of allowing covalent bond relaxation is dramatic. If bond lengths and angles, and dihedral angles within the pyrrolidine ring, are allowed to relax, a calculated energy difference between the alpha and beta conformations of 1.1 kcal/mol is obtained, in reasonable agreement with experiment. The detailed shape of the calculated energy surface is also in excellent agreement with the observed conformational distributions in known protein structures.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-3525
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1443-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Flexible-geometry conformational energy maps for the amino acid residue preceding a proline.
pubmed:affiliation
Institute of Molecular Biology, Howard Hughes Medical Institute, Eugene, Oregon.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't