Development of glycosylated human interleukin-1alpha, neoglyco IL-1alpha, by coupling with D-galactose monosaccharide: synthesis and purification.

In order to develop glycosylated cytokine, recombinant human IL-1alpha was chemically modified with galactose monosaccharide. Galactose with C9 spacer, 8-(hydrazinocarbonyl)octyl beta-D-galactopyranoside (3), was synthesized by glycosylation of C9 spacer, methyl 9-hydroxynonanoate, with acetobromogalactose, followed by deacetylation and hydrazidation. Total yield of 3 was 43.6% in three steps. Compound 3 was coupled to IL-1alpha by the acyl azide method. The glycosylated IL-1 was purified by anion-exchange chromatography, and galactose coupled to IL-1 was confirmed by R. communis lectin blotting. Based on the molecular weight, the average number of carbohydrate molecules introduced per molecule of IL-1alpha was estimated to be 9.1.