Carbohydrate components of lipovitellin of the sand crab Emerita asiatica

Lipovitellin II (Lv II), the major yolk protein of the anomuran crab Emerit a asiatica, was purified using heparin-sepharose affinity column chromatogr aphy. The purified Lv II was a glycoprotein as it was stainable with period ic acid-Schiff's reagent. Quantitative analysis of sugars showed the presen ce of fucose, mannose, galactosamine, N-linked oligosaccharides, as well as O-linked oligosaccharides containing N-acetyl hexosamine as the terminal r esidue. The amount of N-linked oligosaccharides is higher than that of the O-linked oligosaccharides. Biogel P-4 column chromatographic separation of the radiolabeled oligosaccharides of Lv II showed the presence of five diff erent O-linked oligosaccharides and four different N-linked oligosaccharide species. HPTLC separation of the neoglycolipids prepared from the O-linked oligosaccharides also showed the presence of five different O-linked oligo saccharide species. N-linked oligosaccharides contain significant quantitie s of mannose. Unisil column chromatographic purification in conjunction wit h HPTLC separation revealed three neutral glycolipid species such as monogl ycosylceramide, diglycosylceramide, and triglycosylceramide in the iv II. T he functional significance of these carbohydrate components of the major yo lk protein during embryogenesis of the sand crab is discussed. (C) 2001 Wil ey-Liss, Inc.