title: Reevaluation of some properties of fibrinogen, purified from cord blood of normal newborns.
abstract: In this study we compared some properties of fibrinogens, obtained from normal adult and cord plasma. Fibrinogen preparations were made under conditions, which minimize proteolytic breakdown in vitro. We were not able to demonstrate any significant differences between both purified fibrinogens as to the effects of pH and ionic strength on its clotting properties, the Km for thrombin, SDS polyacrylamide gelelectrophoresis behaviour or carbohydrate content. However, the phosphorus content of cord fibrinogen was 3-4 times higher than that of adult fibrinogen. The accelerating effect of calcium on the thrombin clotting time was more pronounced for newborn cord plasma and for purified cord fibrinogen preparations as compared with adult fibrinogen. This might be explained by the higher phosphorus content of the cord fibrinogen molecule. The thrombin clotting time of both purified adult and cord fibrinogen was markedly prolonged, when increasing amounts of fibrinogen degradation product fragment X were added to the fibrinogen solutions under conditions with high pH or high ionic strength. At high pH the effect of adding fragment X was more pronounced in cord fibrinogen preparations. Therefore, mixtures of purified fibrinogen and fragment X have several properties in common with fetal fibrinogen. These observations show, that some of the properties that have been attributed in the literature to a distinct fetal fibrinogen can be caused by the presence of fragment X in the cord fibrinogen preparations.
mesh_terms: D000328:Adult; D000367:Age Factors; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D005333:Fetus; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000032:analysis / Q000302:isolation & purification; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D010758:Phosphorus / Q000097:blood; D011247:Pregnancy; D013918:Thrombin Time
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D010758:Phosphorus; D005340:Fibrinogen