New GlcNAc/GalNAc-specific lectin from the ascidian Didemnum ternatanum

• Published in: Biochimica et biophysica acta Vol. 1723; no. 1; pp. 82 - 90
• Main Authors: Molchanova, Valentina, Chikalovets, Irina, Li, Wei, Kobelev, Stanislav, Kozyrevskaya, Svetlana, Bogdanovich, Raisa, Howard, Eric, Belogortseva, Natalia
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.05.2005
• Subjects: Acetylgalactosamine - metabolism; Acetylglucosamine - metabolism; Amino Acid Sequence; Amino Acids - analysis; Animals; Chromatography, Affinity; Didemnum ternatanum; GlcNAc/GalNAc-specific lectin; Glycoprotein; Hemagglutination; Heparin - metabolism; Hydrogen-Ion Concentration; Invertebrate; Lectins - isolation & purification; Lectins - metabolism; Molecular Weight; Mucins - metabolism; Osmolar Concentration; Sulfated polysaccharide; Urochordata - chemistry; PBS; Invertebrate; Didemnum ternatanum; TBS; Sulfated polysaccharide; HRP; Glycoprotein; GlcNAc/GalNAc-specific lectin; EDTA; BSA; PAA; DTL-A; BSM
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2004.12.022

Previously we isolated GlcNAc-specific lectin (DTL) from the ascidian Didemnum ternatanum by affinity chromatography on cross-linked ovalbumin. Here we report the purification and characterization of new D-GlcNAc/D-GalNAc-specific lectin DTL-A from the same ascidian. This lectin was isolated from non-bound cross-linked ovalbumin fraction and further was purified by gel filtration on Sepharose CL-4B, affinity chromatography on GlcNAc-agarose and gel filtration on Superdex 200. SDS-polyacrylamide gel electrophoresis and gel filtration of purified lectin on Sepharose CL-4B indicates that it exists as large aggregates in the native state. Investigations of the carbohydrate specificity of DTL-A by enzyme-linked lectin assay suggest the multi-specificity of this lectin. DTL-A binds BSM, asialo-BSM as well as heparin and dextran sulfate. The binding of DTL-A to BSM was inhibited by monosaccharides D-GlcNAc and D-GalNAc, their α- but not β-anomers. Among polysaccharides and glycoconjugates, DTL-A binding to BSM was effectively inhibited by BSM, asialo-BSM, pronase-treated BSM and synthetic α-D-GalNAc-PAA. Fetuin and asialofetuin showed a much lower inhibitory potency, heparin and dextran sulfate were noninhibitory. On the other hand, DTL-A binding to heparin was effectively inhibited by dextran sulfate, fucoidan, whereas BSM showed insignificantly inhibitory effect. DTL-A binding to heparin was not inhibited by D-GlcNAc and D-GalNAc.