%0 Journal Article
%T Tn/T Specific Agglutinin from Estuarine Crab Scylla Serrata with Potent Mitogenic Activity on Mouse Splenocytes and Antiproliferative Effect on Hepatocellular Carcinoma (HepG2) Cell
%A Jhuma Pramanik
%A Urmimala Chatterjee
%A Gautam Mondal
%A Patricia Targon Campana and Bishnu Pada Chatterjee
%J Glycobiology Insights
%D 2012
%I 
%R 10.4137/GBI.S4214
%X A lectin was purified from the hemolymph of esturarine crab Scylla serrata by successive 40% (NH4)2SO4 precipitation, affinity chromatography on asialo fetuin- Sepharose column, Resource Q anion-exchanger in FPLC system and designated as scyllin-2. Scyllin-2 was a homogeneous monomeric protein of molecular mass 75 kD judged by SDS-PAGE and confirmed by ESI-MS-Q-ToF. Its activity was Ca+2 dependent being maximum at pH 7.5 and at 20 ¡ãC. N-terminal sequence of scyllin-2 showed close resemblance to peanut lectin and histidine kinase A. It agglutinated human O, A, B and AB blood group erythrocytes equally well and showed maxi- mum inhibition with ¦Á-Gal by hapten-inhibition study. The detailed carbohydrate specificity of scyllin-2 was determined at the macro-molecular level based on the Gal/GalNAc structural units in the mammalian glycoproteins by enzyme-linked lectinosorbent (ELLSA) and inhibition assays. It revealed that scyllin-2 binds specifically to tumor-associated carbohydrate antigens GalNAc¦Á1¡úSer/Thr (Tn) and Gal¦Â1¡ú3GalNAc¦Á1¡úSer/Thr (T¦Á). It showed very weak binding with Gal¦Â1¡ú3/4GlcNAc (I/II) glycotopes on glycoproteins and T/Tn covered by sialic acid. Multivalancy of Tn/T¦Á containing glycoproteins tested resulted in higher binding of 102¨C104 order than the respective Gal and GalNAc monomer. Scyllin-2 stimulated proliferation of mouse splenocytes. Analysis of expression of receptors for scyllin-2 on HepG2 by flow cytometry showed the binding of FITC-scyllin-2 to HepG2 was 86.51%, which was nearly comparable to Artocarpus lakoocha agglutinin (ALA) (66.41%), another Tn/T¦Á specific lectin indicating that the glycan structure on HepG2 cell surface shows prevalence of Tn/T¦Á units. It inhibited proliferation of HepG2 cells (61 ¦Ìg/ml). The inhibitory effect was comparable to ALA (80 ¦Ìg/ml). Thus, we have characterized a Tn/T specific invertebrate lectin with biological significance.
%U http://www.la-press.com/tnt-specific-agglutinin-from-estuarine-crab-scylla-serrata-with-potent-article-a2053