title: Partially carboxylated prothrombins. II. Effect of gamma-carboxyglutamyl residues on the properties of prothrombin fragment 1.
abstract: Purified prothrombin fragments 1 derived from normal (10-carboxyglutamyl) and dicoumarol-induced 7-, 5-, 2-, 1-, and 0-carboxyglutamyl prothrombins contained the same number of gamma-carboxyglutamyl residues as their respective parent molecules. The effect of gamma-carboxyglutamyl residues was more pronounced on the fragments 1 than on the prothrombins. Consequently, the pI values of the fragments 1 were very well differentiated, with normal fragment 1 focusing at pH 3.58, 7-carboxyglutamyl fragment 1 at 3.79, 5- at 3.97, and 2- at pH 4.29. Similarly, by agar gel electrophoresis, normal fragment 1 was the most mobile, followed by 7-, 5-, 2-, 1- and lastly 0-carboxyglutamyl fragment 1. Because of Ca2+ being bound to the carboxyglutamyl residues, the electrophoretic mobility of normal fragment 1, in the presence of Ca2+, was reduced the most, followed by 7-, 5- and then 2-carboxyglutamyl fragment 1, while the mobilities of the 1- and 0-carboxyglutamyl fragments 1 were not affected. In contrast to their parent molecules, all of the fragments 1 in the presence of EDTA gave negative immunoprecipitation reactions against antibodies produced against normal prothrombin. In the presence of Ca2+, conversely, the fragments 1 containing comparable amounts of antigenic activity all gave positive reactions. However, the intensity of the immunoprecipitates varied, as normal fragment 1 gave the most prominent immunoprecipitation reaction, consecutively followed by 7-, 5-, 2-, 1- and lastly 0-carboxyglutamyl fragment 1 where the precipitation was so faint that it was hardly visible.
mesh_terms: D015055:1-Carboxyglutamic Acid / Q000032:analysis; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D001728:Dicumarol / Q000494:pharmacology*; D004587:Electrophoresis, Agar Gel; D000939:Epitopes / Q000276:immunology; D005971:Glutamates / Q000032:analysis; D007163:Immunosorbent Techniques; D007526:Isoelectric Point; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D011516:Prothrombin / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D000939:Epitopes; D005971:Glutamates; D010446:Peptide Fragments; D015055:1-Carboxyglutamic Acid; D001728:Dicumarol; D011516:Prothrombin; D002118:Calcium