Summary
A quantitative determination of soluble fibrin in plasma was carried out by affinity
chromatography. For this purpose, desAA-fibrin and fibrinogen immobilized on Sepharose
4B were used at the stationary side whereas batroxobin-induced 125I-desAA-fibrin or thrombin-induced 125I-desAABB-fibrin mixed with plasma containing 131I-fibrinogen represented the fluid phase. The binding characteristics of these mixtures
to the immobilized proteins were compared at 20° C and 37° C. Complete binding of
both types of fibrin to the immobilized desAA-fibrin was always seen at 20° C as well
as at 37° C. However, binding of soluble fibrin was accompanied by substantial binding
of fibrinogen that was more pronounced at 20° C. Striking differences depending on
the temperature at which the affinity chromatography was carried out, were documented
for the fibrinogen-fibrin interaction. At 20° C more than 90% of the applied desAA-fibrin
was bound to the immobilized fibrinogen whereas at 37° C only a mean of 17% were retained
at the fibrinogen-Sepharose column. An opposite finding with regard to the tested
temperature was made with the desAABB-fibrin. Nearly complete binding to insolubilized
fibrinogen was found at 37° C (95%) but only 58% of the desAABB-fibrin were bound
at 20° C. The binding patterns did not change when the experiments were performed
in the presence of calcium ions. The opposite behaviour of the two types of soluble
fibrin to immobilized fibrinogen at the different temperatures, together with the
substantial binding of fibrinogen in the presence of soluble fibrin to insolubilized
fibrin in every setting tested, devaluates affinity chromatography as a tool in the
quantitative assessment of soluble fibrin in patients’ plasma.
Keywords
Soluble fibrin - Fibrinogen - Affinity chromatography
