title: Do the isolated fibrinogen alphaC-domains form ordered oligomers?
abstract: Previous electron microscopy (EM) studies revealed that the proteolytically prepared, truncated, bovine fibrinogen alphaC-domain (Aalpha223-539 fragment) upon transfer from acidic to neutral pH formed ordered oligomers which could mimic alpha polymers of cross-linked fibrin. In this study, we demonstrated that although its recombinant analog, bAalpha224-538, as well as the full-length version of the alphaC-domain (bAalpha224-568), upon similar treatment also formed oligomers with ordered structure, both were monomeric when kept in neutral pH buffer. To search further for conditions for their oligomerization, we treated bAalpha224-568 with factor XIIIa, purified the cross-linked soluble fraction, and confirmed that it consisted of oligomers. Similar cross-linked oligomers were obtained with the recombinant human alphaC-domain (residues Aalpha221-610). In a cell adhesion assay, the adhesion of human umbilical vein endothelial cells (HUVEC) to the alphaC-domains substantially increased upon oligomerization. These results demonstrate that the recombinant alphaC-domains can form stable oligomers which may mimic properties of the alphaC-domains in cross-linked fibrin.
authors.affiliation: Biochemistry Department, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, 15601 Crabbs Branch Way, Rockville, MD 20855, USA.
authors.forename: Galina
authors.initials: G
authors.lastname: Tsurupa
authors.forename: Yury
authors.initials: Y
authors.lastname: Veklich
authors.forename: Roy
authors.initials: R
authors.lastname: Hantgan
authors.forename: Alexey M
authors.initials: AM
authors.lastname: Belkin
authors.forename: John W
authors.initials: JW
authors.lastname: Weisel
authors.forename: Leonid
authors.initials: L
authors.lastname: Medved
mesh_terms: D000818:Animals; D002417:Cattle; D002448:Cell Adhesion; D019281:Dimerization; D004730:Endothelium, Vascular / Q000166:cytology; D026122:Factor XIIIa / Q000737:chemistry; D005340:Fibrinogen / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D010446:Peptide Fragments; C098000:fibrinogen alphaC; D005340:Fibrinogen; D026122:Factor XIIIa