Biosynthesis and characterization of glycoproteins in Koliella antarctica (Klebsormidiales, Chlorophyta)

• Published in: European Journal of Phycology
• Main Authors: LENUCCI M., LEUCCI M. R., DALESSANDRO G., PIRO G., ANDREOLI, CARLO
• Other Authors: Lenucci, M., Leucci, M. R., Andreoli, Carlo, Dalessandro, G., Piro, G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: TAYLOR & FRANCIS LTD, 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND 2006
• Subjects: Antarctica; D-glucosamine metabolism; glycoprotein biosynthesi; green microalga; Koliella antarctica; lectin binding; Ross Sea; Antarc*
• Online Access: http://hdl.handle.net/11577/1563673; https://doi.org/10.1080/09670260600648596

The biosynthesis of the oligosaccharide chains of glycoproteins in cultures of Koliella antarctica (Klebsormidiales), a green filamentous microalga collected from samples of seawater near the Italian station of Terra Nova (Ross Sea, Antarctica), has been studied by using D-[U-C-14] glucosamine as a tracer. To characterize the oligosaccharide moieties of Koliella glycoproteins, immunolabelling experiments with different lectins have also been performed. The use of radioactive tracer has shown that exogenously supplied D-[U-C-14] glucosamine is taken up by the microalga and sequentially metabolized to soluble radioactive UDP-N-acetylglucosamine and UDP-N-acetylgalactosamine. N-acetylglucosamine and N-acetylgalactosamine residues were incorporated mainly into the oligosaccharide chains of soluble and membrane-bound glycoproteins; the lowest amount of radioactive N-acetylhexosamines was detected in covalently and non-covalently linked cell-wall glycoproteins. Immunolabelling experiments with different lectins have shown similarities and differences among the patterns of soluble, membrane-bound and cell-wall glycoproteins. A peculiar characteristic of these microalgae is the presence of N-acetylgalactosamine residues as a component of the oligosaccharide chains of intracellular and cell wall N-linked glycoproteins.