Mapping Recognition Intensity Profiles of Toxic and Applied Lectins by Carbohydrate Structural Units, Simple Clusters and Natural Polyvalent Glycotopes

Studies on the recognition intensity of toxic and applied lectins and carbohydrate binding proteins from edible mushrooms, seeds, Chinese folk medicines and herbs, such as Solanum tubersum (potato), Horduem vulgarie, Vaccaria pyramidata and Trichosanthis kirilowii toward glycotopes should provide a better understanding of the functional role of lectins and complex carbohydrates in life processes. Lectins can be used to evaluate the different distributions of complex carbohydrates in cancer cells, normal cells, and tissues at the molecular level. These studies also provide important information concerning the development of analytical reagents for serodiagnosis and treatment (immuno-drugs). During the past decades, many toxic and applied lectins have been tested for their medical values. However, knowledge about the binding properties of lectins, such as Viscum album (ML-I, ML-II, ML-III), Abrin-a, Abrin-b, Abrin-c, Momordica charantia and cholera toxin is still limited. In previous years, we have identified two lectins － abrin-a and ML-I that have affinity for Gall4Gal, a receptor of the uropathogenic E. coli toxin and Shiga toxin. We have also a subjects related to “Effect of Polyvalencies of Glycotopes on the Lectin Recognition”[Wu et al., Biochemical J., 371, 311-320, 2003;Wu et al., FEBS Lett., 584: 2371-2375, 2010; Wu et al., FEBS Lett., 584: 3561-3566, 2010; MICC-3, Adv. Exp. Med. Biol., 2011]. In this proposal, the recognition profiles of toxic and applied lectins will be studied by a series of immunochemical methods － enzyme linked lectin-sorbent array (ELLSA) and inhibition of ELLSA, quantitative precipitin assay (QPA) and inhibition of QPA, hemagglutination assay (HA) and inhibition of HA etc [Wu et al., J. Biomed. Sci., 11, 874-885, 2004; Mol. Immunol., 43, 1700-1715, 2006; Glycobiology, 17, 165-184, 2007; Glycoconj. J. 26:899-913, 2009]. In the first part of this plan, lectins of biomedical importance will be characterized with established compounds (glycoproteins and polysaccharides) by ELLSA and inhibition of ELLSA with two or three different glycan systems. The binding intensities of these lectins will be expressed by mammalian glyco-structural units [Wu et al., Mol. Immunol., 46:3427-3437, 2009; Biochimie, 92: 147-156, 2010; Wu et al., Biochemical J., 371, 311-320, 2003]. In the second part of this program, carbohydrate antigens and/or lectin active complex carbohydrates related to cancer cells will be isolated and their glycotopes will be identified and characterized. Furthermore, their binding and structural differences will be illustrated. The third part of this study is to map the recognition profiles of all these lectins to establish lectin recognition index [MICC-3, Adv. Exp. Med. Biol., 2011; MICC-2, Adv. Exp. Med. Biol., 491, 551-585, 2001 and J. Biomed. Sci., 10, 676-688, 2003; Lectin- Analytical Technologies (Ed. CL Nilsson), Elsevier, Amsterdam, NL, 167-192, 2007]. The roles of polyvalency of glycotopes in recognition process should be the theme of this study.

Project ID:PC10008-0873
External Project ID:NSC100-2320-B182-027