Linked Life Data

11741421

Source:http://linkedlifedata.com/resource/pubmed/id/11741421

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
50
pubmed:dateCreated
2001-12-19
pubmed:abstractText
The importance of local (intraresidue) effects in determining the stability of the collagen triple helix has been investigated with special reference to the role played by hydroxyproline. To this end the dipeptide analogues of L-proline (ProDA), 4(R)-hydroxy-L-proline (HypDA), and 4(R)-fluoro-L-proline (FlpDA) have been studied by means of quantum mechanical ab initio calculations, taking into account solvent effects by the polarizable continuum model (PCM). Our results confirm that the relative stability of up puckerings of the pyrrolidine ring increases with the electronegativity of the 4(R) substituent (X), whereas down puckerings are favored by 4(S) electronegative substituents. Calculations on model compounds show that this effect is due to the interaction between vicinal C-H bonding and C-X antibonding orbitals. Electronegative substituents on the pyrrolidine ring affect cis-trans isomerism around the peptidic bond, with trans isomers stabilized by 4(R) substituents and cis isomers by 4(S) substituents. Also the hydrogen bonding power of the carbonyl moiety following the pyrrolidine ring is affected by 4(R) substituents, but this effect is tuned by the polarity of the embedding medium. Finally, up puckering favors smaller values of the backbone dihedrals phi and psi. All these results strongly support the proposal that the stability of triple helices containing fluorinated or hydroxylated prolines in Y positions is related to the necessity of having up puckerings in those positions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
123
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12568-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Understanding the role of stereoelectronic effects in determining collagen stability. 1. A quantum mechanical study of proline, hydroxyproline, and fluoroproline dipeptide analogues in aqueous solution.
pubmed:affiliation
Dipartimento di Chimica, Università Federico II, Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't