Linked Life Data

14695516

Source:http://linkedlifedata.com/resource/pubmed/id/14695516

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-12-25
pubmed:abstractText
The triple-helical fold of collagen requires the presence of a glycine residue at every third position in the peptide sequence and is stabilized by proline and (4R)-4-hydroxyproline residues in positions Xaa and Yaa of the (Xaa-Yaa-Gly) triplets, respectively. Regular down/up puckering of these Xaa/Yaa residues is possibly responsible for the tight packing of the three peptide strands, which have a polyproline-II-like structure, into the supercoiled helix. (4R)-Configured electronegative substituents such as a hydroxy group or a fluorine substituent on the pyrrolidine ring of the residue in the Yaa position favor the up pucker and thus significantly stabilize the triple helix. A similar effect was expected from the corresponding (4S)-isomers in the Xaa positions, but the opposite effect has been observed with (4S)-hydroxyproline, a result that has been speculatively attributed to steric effects. In this study, (4R)- and (4S)-fluoroproline residues were introduced into the Xaa position and potential steric effects were thus avoided. Contrary to expectations, (4S)-fluoroproline prevents triple-helix formation, whereas (4R)-fluoroproline stabilizes the polyPro II conformation, but without supercoiling of the three strands. The latter observation suggests that folding of the single chains into a polyproline II helix is not directly associated with triple helix formation and that fine tuning of van der Waals contacts, electrostatic interactions, and stereoelectronic effects is required for optimal packing into a triple helix.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1439-4227
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
79-86
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
A (4R)- or a (4S)-fluoroproline residue in position Xaa of the (Xaa-Yaa-Gly) collagen repeat severely affects triple-helix formation.
pubmed:affiliation
Max-Planck-Institut für Biochemie, Am Klopferspitz 18A, 82152 Martinsried, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't