Self-association of bovine prothrombin fragment 1 in the presence of metal ions. Use of a covalent cross-linking reagent to study the reaction.
The interaction of metal ions with prothrombin fragment 1 has been shown by other investigators to result in conformational change(s). Previous studies based on hydrodynamic measurements from other laboratories have suggested that prothrombin fragment 1 will, in addition to undergoing conformational change, self-associate in the presence of metal ions but there is a question regarding the specificity and role of metal ions in this process. The present study has made use of a covalent cross-linking agent, dithiobis(succinimidylpropionate), to study the self-association of prothrombin fragment 1 and has focused on factors influencing the covalent dimerization of bovine prothrombin fragment 1 during reaction with this reagent. Optimal dimerization of bovine prothrombin fragment 1 required the involvement of cations in two separable processes. The "first role" is probably a reflection of a slow conformational change in the bovine prothrombin fragment 1 representing isomerization of a proline-containing peptide bond (Marsh, H. C., Scott, M. E., Hiskey, R. G., and Koehler, K. A. (1979) Biochem. J. 183, 513-517). The "second role" most likely reflects ion bridging with another prothrombin fragment 1 molecule. The ion specificities of these two roles are clearly different. Ions stabilizing the proper conformation (first role) are Ca2+, Sr2+, Mg2+, Mn2+, with Ba2+ having less capability in filling this role. Ions which have activity in the second role (ion bridge formation) are Ca2+, Sr2+, and Ba2+. Mn2+ and Mg2+ cannot fulfill the requirements of this second role and actually inhibit the function of Ca2+.
D000818:Animals; D002413:Cations, Divalent; D002417:Cattle; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D007700:Kinetics; D046911:Macromolecular Substances; D008670:Metals / Q000494:pharmacology*; D010446:Peptide Fragments / Q000378:metabolism*; D011487:Protein Conformation; D011498:Protein Precursors; D011516:Prothrombin / Q000302:isolation & purification / Q000378:metabolism*; D013388:Succinimides / Q000494:pharmacology*
D002413:Cations, Divalent; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D008670:Metals; D010446:Peptide Fragments; D011498:Protein Precursors; D013388:Succinimides; C029733:prothrombin fragment 1; D011516:Prothrombin; C011240:dithiobis(succinimidylpropionate)