title: Role of glycosylation in conformational stability, activity, macromolecular interaction and immunogenicity of recombinant human factor VIII.
abstract: Factor VIII (FVIII) is a multi-domain glycoprotein that is an essential cofactor in the blood coagulation cascade. Its deficiency or dysfunction causes hemophilia A, a bleeding disorder. Replacement using exogenous recombinant human factor VIII (rFVIII) is the first line of therapy for hemophilia A. The role of glycosylation on the activity, stability, protein-lipid interaction, and immunogenicity of FVIII is not known. In order to investigate the role of glycosylation, a deglycosylated form of FVIII was generated by enzymatic cleavage of carbohydrate chains. The biochemical properties of fully glycosylated and completely deglycosylated forms of rFVIII (degly rFVIII) were compared using enzyme-linked immunosorbent assay, size exclusion chromatography, and clotting activity studies. The biological activity of degly FVIII decreased in comparison to the fully glycosylated protein. The ability of degly rFVIII to interact with phosphatidylserine containing membranes was partly impaired. Data suggested that glycosylation significantly influences the stability and the biologically relevant macromolecular interactions of FVIII. The effect of glycosylation on immunogenicity was investigated in a murine model of hemophilia A. Studies showed that deletion of glycosylation did not increase immunogenicity.
authors.affiliation: Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Amherst, NY 14260, USA.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Kosloski
authors.forename: Razvan D
authors.initials: RD
authors.lastname: Miclea
authors.forename: Sathy V
authors.initials: SV
authors.lastname: Balu-Iyer
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005169:Factor VIII / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D006031:Glycosylation; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology
chemical_list: D011994:Recombinant Proteins; D005169:Factor VIII