Characterization of the okra mucilage by interaction with Gal, Ga1NAc and GlcNAc specific lectins

• Published in: Biochimica et biophysica acta. General subjects Vol. 1243; no. 2; pp. 157 - 160
• Main Authors: Wu, Albert M, Jiang, Yia-jen, Hwang, P.Y, Shen, F-shiun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 23.02.1995
• Subjects: Carbohydrate binding property; Carbohydrate combining site; Carbohydrate epitope; Lectin; Okra mucilage; Lectin; Gal, d-galactopyranose; l-Fuc, l-fucopyranose; GlcNAc, 2-acetamido-2-deoxy- d-glucopyranose; l-Rha, l-rhamnose; Carbohydrate binding property; Carbohydrate epitope; Abbreviations of lectins and lectin determinants are shown in Table 1; GalNAc, 2-acetamido-2-deoxy- d- galactopyranose; Carbohydrate combining site; Glc, d-glucopyranose; Except where indicated, all sugar abbreviations correspond to the d-form; GalUA, d-galacturonic acid; Okra mucilage
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/0304-4165(94)00130-P

A bio-active polysaccharide, which was the major component of the aqueous extract of the common okra, Hibiscus esculentus, was isolated from the extract by precipitation with ethanol between 28.5 to 45%. According to a previous report (Whistler, R.L. and Conrad, H.E. (1954) J. Am. Chem. Soc. 76, 1673–1674), this polysaccharide contains the Gal α1 → 4Gal sequence, which is the ligand for the uropathogenic Escherichia coli and toxic lectins. Analysis of the binding property of the okra polysaccharide by precipitin assay with Gal, GalNAc and GlcNAc specific lectins showed that this okra mucilage reacted best with Mistletoe toxic lectin-I (ML-I) and precipitated over 80% of the ML-I nitrogen (5.1 μg N) added. It also precipitated well with Abrus precatorius (APA), Momordica charantia (MCA) and Ricinus communis (RCA1) agglutinins, but poorly with other lectins. The results obtained suggest that this polysaccharide is a valuable reagent to differentiate Gal specific lectins from the GalNAc and/or GlcNAc specific series.