Characterization of a monoclonal antibody specific to the amino terminus of the alpha-chain of human fibrin.
A peptide, Gly-Pro-Arg-Val-Val-Glu, corresponding to the first six residues of the amino terminus of the alpha-chain of human fibrin (desAA-fibrin) was prepared by solid-phase peptide synthesis. The peptide was covalently linked to keyhole-limpet hemocyanin (KLH) and used as an immunogen for preparing monoclonal antibodies. A monoclonal antibody specific to the hexapeptide, but not to KLH or fibrinogen, was produced. The antibody did not bind to thrombin-mediated clots prepared from either plasma or purified fibrinogen. However, immunoreactivity was detected when fibrin (prepared from fibrinogen) was solubilized with 8 M urea. In contrast, a monoclonal antibody specific to the amino terminus (Gly-His-Arg-Pro-Leu-Asp-Lys) of the beta-chain of fibrin recognized the epitope in clots. These results indicate that thrombin cleavage of fibrinogen produces a structural change in the amino terminal domain of the alpha-chain that makes it inaccessible to antibody interaction. In addition, our study suggests that the potential clinical application of monoclonal antibodies to localize fibrin-rich thrombi must take into account the final structure of clots.
Merrell Dow Research Institute, Cincinnati, OH 45215.
S J
SJ
Mao
A E
AE
Rechtin
J L
JL
Krstenansky
R L
RL
Jackson
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005337:Fibrin / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D011485:Protein Binding; D012995:Solubility; D013927:Thrombosis / Q000097:blood
D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D005337:Fibrin; C065735:glycyl-prolyl-arginyl-valyl-valyl-glutamic acid