title: Characterization of the self-association of human interferon-α2b, albinterferon-α2b, and pegasys.
abstract: The self-association of human interferon-α2b (hIFN-α2b), albinterferon-α2b (a recombinant protein with human serum albumin and hIFN-α2b peptides fused together in a single polypeptide chain), and Pegasys (PEGylated hIFN-α2a) was characterized by analytical ultracentrifugation analyses. By examining the apparent sedimentation coefficient distribution profiles of each protein at different concentrations, it was concluded that the above three proteins are self-associating in albinterferon-α2b formulation buffer. By model fitting of sedimentation data using SEDANAL software, the stoichiometry and equilibrium constants of the self-association of these proteins were characterized. The self-association of hIFN-α2b results in the formation of stable dimers, fast-reversible tetramers, octamers, and hexadecamers. In contrast, although both albinterferon-α2b and Pegasys are self-associated, their self-association stoichiometries are significantly different from that of hIFN-α2b. The self-association of albinterferon-α2b results in the formation of reversible dimers and trimers, whereas the self-association of Pegasys gives only reversible dimers. The self-association behaviors of hIFN-α2b and albinterferon-α2b involves attractive electrostatic forces, which can be suppressed to a negligible level in low pH (pH 4.0-4.5) and high salt concentration (400 mM NaCl) buffer, allowing quantification of their size variant contents by sedimentation velocity analysis.
authors: Human Genome Sciences, Inc, Rockville, Maryland 20850, USA. LiYi@Medimmune.com
authors: Yiming
authors: Y
authors: Li
authors: Walter F
authors: WF
authors: Stafford
authors: Mark
authors: M
authors: Hesselberg
authors: David
authors: D
authors: Hayes
authors: Zhuchun
authors: Z
authors: Wu
authors: Michael
authors: M
authors: Byrne
mesh_terms: D000418:Albumins / Q000737:chemistry*; D002021:Buffers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016898:Interferon-alpha / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D009994:Osmolar Concentration; D011092:Polyethylene Glycols / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry*; D012492:Salts; D055672:Static Electricity; D014461:Ultracentrifugation / Q000379:methods
chemical_list: D000418:Albumins; D002021:Buffers; C554158:IFNA2 protein, human; D016898:Interferon-alpha; D011994:Recombinant Proteins; D012492:Salts; D011092:Polyethylene Glycols; C531108:albinterferon alfa-2b; C100416:peginterferon alfa-2a