title: Positional isomers of monopegylated interferon alpha-2a: isolation, characterization, and biological activity.
abstract: The success of recombinant interferon alpha in the clinic in part is limited by two properties of the protein: short serum half-life and immunogenicity. To improve these properties, interferon alpha-2a was conjugated with polyethylene glycol (PEG-5000). A homogeneous preparation of monopegylated interferon alpha-2a was subjected to vigorous analytical and activity characterization. A newly developed ampholyte-free chromatofocussing-like cation-exchange HPLC method utilizing a sulfopropyl resin was used to separate the monopegylated protein into 11 species. Peptide mapping, sequencing, and mass spectrometric analyses indicated that these species are positional isomers where each isomer represents a single polymer molecule conjugated to one specific lysine residue. No species with a modification at the amino terminus was observed. All 11 isomers show antiviral and antiproliferative activities in the same range as the parent monopegylated interferon alpha-2a.
authors.affiliation: Department of Biopharmaceuticals, Hoffmann-La Roche Inc., Nutley, New Jersey 07110, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Monkarsh
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: A
authors.initials: A
authors.lastname: Aglione
authors.forename: P
authors.initials: P
authors.lastname: Bailon
authors.forename: D
authors.initials: D
authors.lastname: Ciolek
authors.forename: B
authors.initials: B
authors.lastname: DeBarbieri
authors.forename: M C
authors.initials: MC
authors.lastname: Graves
authors.forename: K
authors.initials: K
authors.lastname: Hollfelder
authors.forename: H
authors.initials: H
authors.lastname: Michel
authors.forename: A
authors.initials: A
authors.lastname: Palleroni
authors.forename: J E
authors.initials: JE
authors.lastname: Porter
authors.forename: E
authors.initials: E
authors.lastname: Russoman
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.forename: Y C
authors.initials: YC
authors.lastname: Pan
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004285:Dogs; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D007536:Isomerism; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D011994:Recombinant Proteins
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; C100416:peginterferon alfa-2a