Linked Life Data

8019139

Source:http://linkedlifedata.com/resource/pubmed/id/8019139

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1994-8-4
pubmed:abstractText
The snake venom protein echistatin contains the cell recognition sequence Arg-Gly-Asp and is a potent inhibitor of platelet aggregation. The three-dimensional structure of echistatin and the dynamics of the active RGD site are presented. A set of structures was determined using the Distance Geometry method and subsequently refined by Molecular Dynamics and energy minimization. Disulfide pairings are suggested, based on violations of experimental constraints. The structures satisfy 230 interresidue distance constraints, derived from nuclear Overhauser effect measurements, five hydrogen-bonding constraints, and 21 torsional constraints from vicinal spin-spin coupling constants. The segment from Gly5 to Cys20 and from Asp30 to Asn42 has a well-defined conformation and the Arg-Gly-Asp sequence, which adopts a turn-like structure, is located at the apex of a nine-residue loop connecting the two strands of a distorted beta-sheet. The mobility of the Arg-Gly-Asp site has been quantitatively characterized by 15N relaxation measurements. The overall correlation time of echistatin was determined from fluorescence measurements, and was used in a model-free analysis to determine internal motional parameters. The active site has order parameters of 0.3-0.5, i.e., among the smallest values ever observed at the active site of a protein. Correlation of the flexible region of the protein as characterized by relaxation experiments and the NMR solution structures was made by calculating generalized order parameters from the ensemble of three-dimensional structures. The motion of the RGD site detected experimentally is more extensive than a simple RGD loop 'wagging' motional model, suggested by an examination of superposed solution structures.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0925-2738
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
307-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Three-dimensional structure of echistatin and dynamics of the active site.
pubmed:affiliation
Chemistry Department, Rutgers University, Piscataway, NJ 08855.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't