Studies on circulating soluble fibrin: separation of 125I-Des-AB fibrin and 131I-fibrinogen by gel filtration.
The behaviour of labelled des-AB fibrin in plasma was studied by gel filtration after it had been injected into rabbits. Purified rabbit [125I]des-AB fibrin was prepared by clotting of [125I]fibrinogen by thrombin and solubilizing the formed clot in buffered 3 M urea. Gel filtration of this material on urea-equilibrated columns showed a single peak identical to the elution profile of fibrinogen. This indicated the existence of monomeric des-AB fibrin. When plasma from rabbits injected with monomeric [125I]des-AB fibrin and [131I]fibrinogen was gel-filtered through plasma-equibrated columns, two separate peaks of radioactivities were obtained. The first peak eluted mainly with the void volume and contained [125I]des-AB fibrin whereas the second peak eluting within the fractionation range contained [131I]fibrinogen. Identical elution profiles were obtained in in vitro studies when monomeric [125I]des-AB fibrin was mixed with plasma containing [131I]fibrinogen and gel-filtered through plasma-equilibrated columns. We conclude from these studies that monomeric des-AB fibrin formed high-molecular weight aggregates or changed its conformation posing as a larger molecule than fibrinogen when injected into rabbits. No complex formation between des-AB fibrin and fibrinogen was observed as [131I]fibrinogen was not incorporated into des-AB fibrin aggregates. Thus, soluble des-AB fibrin can circulate in the blood without forming fibrin-fibrinogen complexes.
D000818:Animals; D002850:Chromatography, Gel; D004492:Edetic Acid; D005260:Female; D005337:Fibrin / Q000302:isolation & purification / Q000502:physiology*; D005340:Fibrinogen / Q000302:isolation & purification; D046911:Macromolecular Substances; D008297:Male; D011487:Protein Conformation; D011817:Rabbits
D046911:Macromolecular Substances; D005337:Fibrin; D005340:Fibrinogen; D004492:Edetic Acid