N-LINKED SUGAR CHAIN OF 55-KDA ROYAL JELLY GLYCOPROTEIN

An N-linked sugar chain from 55-kDa royal jelly glycoportein (RJGP), w hich maintains the high viability of rat liver primary cultured cell a nd is a different molecular species from 350-kDa RJGP [Kimura et al., Biosci, Biotech. Biochem., 59, 507-509 (1995)], has been identified, T he sugar chains mere released by hydrazinolysis followed by N-acetylat ion and pyridylamination. The structural analysis of the pyridylaminat ed sugar chain was done by a combination of sequential eso-mannosidase digestions, MALDI-TOF MS, and 500 MHz H-1-NMR. For the carbohydrate m oiety of 55-kDa RJGP, only one N-linked sugar chain has been detected. The structure has been found to be Man alpha 1-->2Man alpha 1-->6(Man alpha 1-->2Man alpha 1-->3)Man alpha 1-->6(Man alpha 1-->2Man alpha 1 -->2Man alpha 1-->3)Man beta 1-->4GlcNAc beta 1-->4GlcNAc, which is a non-processed high mannose type structure.