Characterization of N-Linked Carbohydrate Chains of the Crayfish,Astacus leptodactylusHemocyanin

Abstract

The primary structure of the carbohydrate chains of hemocyanin from the crayfish Astacus leptodactylus were investigated. The carbohydrate content is 0.2% (w/w) as referred to total hemocyanin content, resp. 1.8% as referred only to the one subunit which is glycosylated. Mannose and N-acetylglucosamine are present in a molar ratio of 6:2. The carbohydrate chains are N-glycosidically linked as revealed by dot blot analysis using various lectins and enzymatic deglycosylation. Furthermore, they are part of only one hemocyanin subunit of A. leptodactylus. After enzymatic deglycosylation with PNGase F, the oligosaccharide pool was separated by FPLC on Mono Q and subsequent HPLC on Lichrosorb-NH2, the subfractions were characterized by 1H NMR spectroscopy. A total of six oligosaccharides, ranging from Man4GlcNAc2 to Man9GlcNAc2 is present, Man6GlcNAc2 representing the most abundant one with 57% of all oligosaccharides.

N-glycan moieties of the crustacean egg yolk protein and their glycosylation sites

“…The treatment of this Vg with GNA indicated the presence of N-glycosylation of the high mannose type (Fig. 2); this finding is consistent with the common glycosylation of arthropod glycoproteins, such as the hemocyanin of Astacus leptodactylus [30], the hemoglobins of the deep-sea tube worm Riftia pachyptila [31], the larval serum protein of Drosophila melanogaster [32], and the storage glycoprotein, arylphorin, of lepidopteran insects [20,33]. As was to be expected, no interaction was found with either of the sialic-acid-specific lectins, SNA and MAA.…”

Characterization of the N-linked oligosaccharides from human chorionic gonadotropin expressed in the methylotrophic yeast Pichia pastoris

“…5b, Scheme 1, Table 1). Man-3 H-2 signal (5%) at δ 4.23 [41,46,48], support the presence of structure Q0.M9-2, the convential precursor Man 9 GlcNAc 2 structure formed in the oligosaccharide processing of Glc 3 Man 9 GlcNAc 2 .…”

“…In [46]. The identified isomer, reflecting the usual first steps in trimming Glc 3 Man 9 GlcNAc 2 of Nglycans, has been reported to be an essential intermediate in yeast oligosaccharide processing [27,47].…”

Structural characterisation of theN-glycan moiety of the barnacle settlement-inducing protein complex (SIPC)

“…N-Linked glycans enzymatically liberated from the SIPC were found to be high mannose-type, ranging from M2 to M9. Previous studies have reported the presence of similar oligosaccharide structures on the proteins isolated from other aquatic organisms such as haemocyanin from the crayfish Astacus leptodactylus (Tseneklidou-Stoeter et al, 1995) and haemoglobins from the hydrothermal vent tube worm Riftia pachyptila (Zal et al, 1998).…”