Linked Life Data

14992584

Source:http://linkedlifedata.com/resource/pubmed/id/14992584

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2004-3-2
pubmed:databankReference
pubmed:abstractText
We synthesized three fibrinogen variants, BbetaE397A, BbetaD398A, and BbetaD432A, with substitutions at positions identified in crystallographic studies as critical for binding the "B" peptide, Gly-His-Arg-Pro-amide (GHRPam), to the "b" polymerization site. We examined thrombin- and batroxobin-catalyzed polymerization by turbidity measurements and found that BbetaE397A and BbetaD398A were impaired while BbetaD432A was normal. Changes in polymerization as a function of calcium were similar for variant and normal fibrinogens. We determined crystal structures of fragment D from the variant BbetaD398A in the absence and presence of GHRPam. In the absence of peptide, the structure showed that the alanine substitution altered only specific local interactions, as alignment of the variant structure with the analogous normal structure resulted in an RMSD of 0.53 A over all atoms. The structure also showed reduced occupancy of the beta2 calcium-binding site that includes the side chain carbonyl of BbetaD398, suggesting that calcium was not bound at this site in our polymerization studies. In the presence of peptide, the structure showed that GHRPam was not bound in the "b" site and the conformational changes associated with peptide binding to normal fragment D did not occur. This structure also showed GHRPam bound in the "a" polymerization site, although in two different conformations. Calcium binding was associated with only one of these conformations, suggesting that calcium binding to the gamma2-site and an alternative peptide conformation were induced by crystal packing. We conclude that BbetaE397 and BbetaD398 are essential for the "B:b" interaction, while BbetaD432 is not.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Alanine, http://linkedlifedata.com/resource/pubmed/chemical/Arginine, http://linkedlifedata.com/resource/pubmed/chemical/BBeta fibrinogen, http://linkedlifedata.com/resource/pubmed/chemical/Batroxobin, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Fibrin Fibrinogen Degradation..., http://linkedlifedata.com/resource/pubmed/chemical/Fibrinogen, http://linkedlifedata.com/resource/pubmed/chemical/Fibrinopeptide A, http://linkedlifedata.com/resource/pubmed/chemical/Fibrinopeptide B, http://linkedlifedata.com/resource/pubmed/chemical/Glutamic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Polymers, http://linkedlifedata.com/resource/pubmed/chemical/Protein Subunits, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Thrombin, http://linkedlifedata.com/resource/pubmed/chemical/fibrinogen D fragment
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2465-74
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
B beta Glu397 and B beta Asp398 but not B beta Asp432 are required for "B:b" interactions.
pubmed:affiliation
Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-7525, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.