Aa. Kramerov et al., MUCIN-TYPE GLYCOPROTEIN FROM DROSOPHILA-MELANOGASTER EMBRYONIC-CELLS - CHARACTERIZATION OF CARBOHYDRATE COMPONENT, FEBS letters, 378(3), 1996, pp. 213-218
A secreted glycoprotein (GP) with apparent molecular mass of 90 kDa pr
oduced by cultured embryonic cells of Drosophila melanogaster was isol
ated and partially characterized. GP is enriched by Ser + Thr and Pro
residues that constitute up to 30% of the total number of amino acids.
An abundant carbohydrate moiety (40% of molecular mass) is mainly rep
resented by vertebrate mucin-type O-linked disaccharide units Gal(beta
1-3)-GalNAc, occupying about a half of the total number of Ser + Thr
residues and rendering the GP molecule high resistance to protease act
ion. A few of N-glycans are also present in GP. These characteristics
allow to consider the Drosophila GP (termed 'mucin-D') as a first repr
esentative of invertebrate mucin-type glycoproteins.