Coenzyme Q₀ Derivative from Fibrin Clots

Abstract

DURING my investigation of clotting and lytic factors from fibrin clots, I observed that on boiling in 1 N hydrochloric acid the clots disintegrated and consistently turned a faintly purple colour. Attempts to extract the pigment from the fibrin residue were unsuccessful. To learn more about this compound, 1 1. of normal citrated human plasma was recalcified, the fibrin digested with 1,000,000 units of crystalline bovine trypsin in distilled water at 37° C overnight, and the undigested sediment, making up about 0.5 ml., washed 3 times in saline and once in distilled water. 2 ml. of 1 N hydrochloric acid were then added, and the mixture was placed in a boiling water bath for 10 min. The change in colour of the sediment was again noted, yet following centrifugation some pigment was also seen in the supernatant. It was slightly reddish, but on neutralization with sodium hydroxide became yellow. After drying in the presence of the salt, the pigment could not be taken up in any organic solvent except methanol, and in it only partially. Since chromatographic separation proved possible, strong adsorption to solids appeared to be one of its characteristics. The partially purified pigment in distilled water gave a distinct ultra-violet spectrum, with a minimum at 250 mµ and a maximum at 265 mµ Some pigment was liberated from digested fibrin with β-glucuronidase, but the amount found in the supernatant was much smaller than when boiling with acid was carried out.