Precipitation of Soluble Fibrin Monomer Complexes SFMC by Cellular Basic Proteins, and the Antagonistic Effect of Sulfonated Mucopolysaccharides

Summary Histones from calf thymus and liver were found to precipitate 131I-SFMC and to neutralize anticlotting activity of heparin nearly as efficiently as protamine. Lysozyme showed both activities but had to be used in tenfold higher concentrations to induce similar effects. Cytochrome C neutralized heparin but did not precipitate SFMC. Heparin, chrondroitin sulfate, and bovine aorta extracts inhibited precipitation of SFMC induced by protamine and histones.