The role of fibronectin fragments and cell-attached transamidase on the binding of soluble fibrin to macrophages.
Proteolytic fragments from the N-terminus of the fibronectin subunit chains were shown to mediate the binding of 125-I-fibrin to macrophages. With increasing molecular weight of the fragments, binding activity decreased and intact plasma fibronectin was inactive. Fibrin binding to macrophages was a time dependent reaction and proceeded considerably faster than binding of fibrinogen. The binding reaction was inhibited by putrescine suggesting the involvement of a transamidase. Pericellular transamidase was demonstrated on macrophages by incorporation of 14-C-putrescine into fibronectin 30 kD-fragment. Expression of this enzyme appeared to be rate-limiting for the binding reaction which was accelerated after loading the cells with placental transamidase.
D000217:Acyltransferases / Q000378:metabolism*; D019881:Aminoacyltransferases; D000818:Animals; D005337:Fibrin / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism*; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D011700:Putrescine / Q000378:metabolism
D005353:Fibronectins; D010446:Peptide Fragments; D005337:Fibrin; D005340:Fibrinogen; D000217:Acyltransferases; D019881:Aminoacyltransferases; C023175:transamidases; D011700:Putrescine