A hydrophobic site in human prothrombin present in a calcium-stabilized conformer.
Human prothrombin and prothrombin fragment 1 were demonstrated to bind to Phenyl-TSK columns in the presence of 5.0 mM calcium ions but not in the presence of either magnesium ions or manganese ions. The calcium-dependent interaction of prothrombin fragment 1 is markedly reduced upon oxidation of approximately one mole of tryptophan per mole of protein. The ability of prothrombin fragment 1 to inhibit prothrombin activation by factor Xa in the presence of calcium ions and phospholipid is also markedly reduced by reaction with N-bromosuccinimide. These results provide the first demonstration of a calcium-specific site in prothrombin outside of the "GLA domain".
Lundblad
R L
RL
Dental Research Center, University of North Carolina, Chapel Hill 27599-7455.
D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D002845:Chromatography / Q000379:methods; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D010446:Peptide Fragments; D011487:Protein Conformation / Q000187:drug effects; D011516:Prothrombin; D012995:Solubility; D014364:Tryptophan
D010446:Peptide Fragments; D014364:Tryptophan; D011516:Prothrombin; D008274:Magnesium; D002118:Calcium