The sequence A alpha-(148-160) in fibrin, but not in fibrinogen, is accessible to monoclonal antibodies.

Abstract

Fibrin, but not fibrinogen, accelerates the activation of plasminogen catalyzed by tissue-type plaminogen activator. Previous work showed that essential information for this accelerating capacity of fibrin resides in the sequence corresponding to residues 148-160 of the A alpha chain of fibrinogen [A alpha-(148-160)]. Our working hypothesis, based on those findings, is that A alpha-(148-160) is buried in fibrinogen and becomes accessible to proteins such as plasminogen and/or tissue-type plasminogen activator when fibrinogen is converted to fibrin. To test this hypothesis we have raised a monoclonal antibody against synthetic A alpha-(148-160) and found that this antibody reacts with fibrin and not with fibrinogen. This finding shows that A alpha-(148-160) becomes accessible when fibrinogen is converted to fibrin and that A alpha-(148-160) is a fibrin-specific neoantigenic determinant.

The Assembly of Nonadhesive Fibrinogen Matrices Depends on the αC Regions of the Fibrinogen Molecule

“…monoclonal antibodies that reside in the coiled-coil connectors of fibrinogen and that are apparently shielded by the interacting ␣C regions in the intact molecule (25,35). In addition, immobilization of fibrinogen on the surface results in unmasking of cryptic binding sites for several components of the fibrinolytic system (tissue plasminogen activator and ␣2-antiplasmin) that reside in the ␣C regions themselves (36,37).…”

The comparison of peroxynitrite action on bovine, porcine and human fibrinogens

“…Maybe localizations of six non conserved tyrosines might be crucial in this case, however two conserved tyrosines probably are important for fibrinogen function. From these 2 conserved tyrosines only Tyr178 is conserved in all vertebrates [47], might be nitrated in human fibrinogen [48] and is located near the place of t-Pa plasminogen activation [49][50][51][52]. There are also suggestions that this location may be important for fibrinogen polymerization and fibrin lysis.…”

Light sensitivity in a vertebrate mechanoreceptor?

“…The polyclonal antibody (CERN972) was raised against a 15-mer peptide covering residues 216-230 of Xenopus laevis OPN4x (FLAIRSTGRNVQKLG) (Provencio et al, 1998). The peptide was linked to rabbit serum albumin using SATA-MHS (Schielen et al, 1989). The resulting construct was injected in albino female New Zealand rabbits and processed as previously described (de Grip, 1985).…”