Screening of lectins by an enzyme-linked adsorbent assay

This study provides a new strategy to detect the specific carbohydrate binding capability of lectins. A sugar-polymer based enzyme-linked adsorbent assay was established by applying different monosaccharide–polyacrylamide conjugates as capturing agents for screening lectins in biological samples. Four model lectins, concanavalin A (Con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA) and Ulex europaeus agglutinin I (UEA I), were employed as the comparative lectins against each corresponding sugar. The results suggested that this assay is more sensitive than the conventional hemagglutinating methods. On the screening of specific carbohydrate binding capability from biological materials, extracts of papaya (Carica papaya) seeds, longan (Euphoria longana) seeds and sorghum (Sorghum bicolor) were shown various specific monosaccharide binding capabilities which had not been reported before. In conclusion, the assay provides an alternative and efficacious detection for the specific carbohydrate binding substances in biological samples.