The Micromolecular Fibrinogen Derivatives: Fractionation by Ultrafiltration and Cation-Exchange Chromatography

The micromolecular fibrinogen derivatives were fractionated by successive ultrafiltrations through the Araicon membranes UM10, UM2 and UM05 into three fractions which represented approx. 9%, 2% and 1.5% of the weight of fibrinogen. Assuming that the fragments behaved as spherical molecules, fraction 10-2 contained mainly fragments with mol. weights of 1,000–10,000; fraction 2–05 contained fragments with mol. weights of 500–1,000 and the 05 fraction contained fragments with mol. weights smaller than 500. Cation exchange chromatography on the aminex resin Spinco PA-35 at a high sensitivity range indicated that there were 19–21 fragments in the 10-2 fraction, 10–12 fragments in the 2–05 fraction and 20–22 fragments in the 05 fraction. Relative to fibrinogen, all three fractions were poor in amino acids absorbing light at 280 mu. The two larger fractions were able to prolong the thrombin, prothrombin and partial thromboplastin times of plasma and could also delay the generation of plasma thromboplastin.