The oligosaccharide side chains of the murine invariant chain (I(i)) glycoprotein associated with the Ia antigens have been characterized. Affinity chromatography using a monoclonal antibody column was employed to purify the I-A(k) antigen from lysates of the AKTB-1b B cell lymphoma. The invariant chain isolated by this procedure was subsequently digested with proteases, and the resulting glycopeptides were fractionated by reverse-phase high-pressure liquid chromatography (HPLC). The invariant chain appears to contain two glycosylation sites, both of which carry high-mannose oligosaccharides, each with a restricted size distribution and an average composition of Man6GIcNAc2 as judged by gel filtration and α-mannosidase digestion. These data, together with the observation that the invariant chain cannot be labeled metabolically with 3H-glucosamine, 3H-fucose, or 3H-galactose, allow the conclusion that the murine invariant chain does not contain complex oligosaccharides and is not O-glycosylated during its association with the Ia antigens.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|Publication status||Published - 1983|
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