title: Crystal structure of fragment double-D from human fibrin with two different bound ligands.
abstract: Factor XIII-cross-linked fragment D (double-D) from human fibrin was crystallized in the presence of two different peptide ligands and the X-ray structure determined at 2.3 A. The peptide Gly-Pro-Arg-Pro-amide, which is an analogue of the knob exposed by the thrombin-catalyzed removal of fibrinopeptide A, was found to reside in the gamma-chain holes, and the peptide Gly-His-Arg-Pro-amide, which corresponds to the beta-chain knob, was found in the homologous beta-chain holes. The structure shows for the first time that the beta-chain knob does indeed bind to a homologous hole on the beta-chain. The gamma- and beta-chain holes are structurally very similar, and it is remarkable they are able to distinguish between these two peptides that differ by a single amino acid. Additionally, we have found that the beta-chain domain, like its gamma-chain counterpart, binds calcium.
authors.affiliation: Center for Molecular Genetics, University of California, San Diego, La Jolla, California 92093-0634, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Everse
authors.forename: G
authors.initials: G
authors.lastname: Spraggon
authors.forename: L
authors.initials: L
authors.lastname: Veerapandian
authors.forename: M
authors.initials: M
authors.lastname: Riley
authors.forename: R F
authors.initials: RF
authors.lastname: Doolittle
mesh_terms: D018360:Crystallography, X-Ray; D005338:Fibrin Fibrinogen Degradation Products / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D010455:Peptides; D011487:Protein Conformation
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D008024:Ligands; D010455:Peptides; C036309:fibrin fragment D