Expression of human interferon ω1 in Sf9 cells : no evidence for complex-type N-linked glycosylation or sialylation

• Published in: European journal of biochemistry Vol. 217; no. 3; pp. 913 - 919
• Main Authors: VOSS, T, ERGÜLEN, E, AHORN, H, KUBELKA, V, SUGIYAMA, K, MAURER-FOGY, I, GLÖSSL, J
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01.11.1993
• Subjects: Antineoplastic drugs. Cytokines; Biological and medical sciences; Biotechnology; Fundamental and applied biological sciences. Psychology; Health. Pharmaceutical industry; Industrial applications and implications. Economical aspects; Production of active biomolecules; Human; Heterologous system; Insecta; Cytokine; Spodoptera frugiperda; Glycosylation; Baculovirus; Gene expression; Virus; Baculoviridae; Structure activity relation; Arthropoda; Lepidoptera; Noctuidae; Recombinant protein; Invertebrata; Vector; Structural analysis
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1993.tb18321.x

Human interferon ω1 (IFN‐ω1) was expressed in Spodoptera frugiperda Sf9 insect cells using the baculovirus expression system. Half of the protein purified by immunoaffinity chromatography was shown to be N‐glycosylated at the same site as the natural IFN‐ω1. The degree of glycosylation was independent of the expression rate. While natural IFN‐ω1 was shown to carry complex‐type oligosaccharides [Adolf, G. R., Maurer‐Fogy, I., Kalsner, I. & Cantell, K. (1990) J. Biol. Chem. 265 , 9290–9295], the insect cell produced protein which was demonstrated by lectin blot, mass spectroscopy and HPLC analysis to contain only the core oligosaccharide. Two different structures, (Man) 2 (GlcNAc) 2 [Fuc] and (Man) 3 (GlcNAc) 2 [Fuc] were identified. The fucosylation was identified to be (α1–6)‐linked to the core saccharide. Sialic acid residues were clearly absent. IFN‐ω1 expressed in S. frugiperda cells was shown to be partially truncated at the C‐terminus by nine residues; its antiviral activity when glycosylated was significantly lower than the activity of IFN‐ω1 produced by Sendai‐virus‐stimulated leukocytes. Circular dichroism and fluorescence spectroscopy did not reveal any structural differences between glycosylated and nonglycosylated IFN‐ω1. This implies the importance of a complex‐type glycosylation for the maximal biological activity of human IFN‐ω1.