title: Homo- and heterodimer formation with prothrombin and prothrombin fragment 1 in the presence of calcium ions.
abstract: The purpose of the current study is to present further evidence for prothrombin self-association as assessed by chemical crosslinking. When the self-association (evaluated by covalent crosslinking with dithiobis(succinimidylpropionate) of prothrombin or fragment 1 was evaluated at the same molar concentration of protein, similar rates of dimer formation were observed for either protein. When prothrombin and fragment 1 were incubated together with the crosslinking reagent and calcium ions, a heterodimer consisting of prothrombin and fragment 1 was observed in addition to prothrombin dimer and fragment 1 dimer. Similar experiments with prethrombin 1 showed neither significant self-association nor effect on prothrombin self-association. Comparison of the formation of prothrombin fragment 1 heterodimer formation with the effect of fragment 1 on prothrombin activation by factor Xa suggests that the anticoagulant activity of fragment 1 is not solely a result of the formation of a heterodimer between prothrombin and fragment 1.
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood*; D002417:Cattle; D004789:Enzyme Activation; D015951:Factor Xa; D007700:Kinetics; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D011516:Prothrombin / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D046911:Macromolecular Substances; D010446:Peptide Fragments; D011498:Protein Precursors; C029733:prothrombin fragment 1; D011516:Prothrombin; D012697:Serine Endopeptidases; D015951:Factor Xa; D002118:Calcium