Lectins detection

Zhao, J., T. H. Patwa, W. Qiu, K. Shedden, R. Hinderer, D. E. Misek, M. A. Anderson, D. M. Simeone, and D. M. Lubman. 2007. Glycoprotein micro-arrays with multi-lectin detection Unique lectin binding patterns as a tool for classifying normal, chronic pancreatitis and pancreatic cancer sera. J. Proteome Res. 6 1864—74. 

Figure 24.4 Lectins coated on gold particles can be used to detect specific carbohydrate sequences in cell-surface glycoconjugates.

Other molecules can be used in this type of assay approach. Hydrazide-modified (strept)avidin, lectins, biocytin, fluorescent probes and other detectable molecules can be used to detect specifically glycoconjugates in biological samples (Wilchek and Bayer, 1987). 

Babu, P., Sinha, S., and Surolia, A. (2007) Sugar-quantum dot conjugates for a selective and sensitive detection of lectins. Bioconjugate Chem. 18, 146-151. 

As an example of the use of antibodies labeled with alkaline phosphatase for detection of in situ hybridization, an infection with BNYVV virus in sugar beet is shown in Fig. 3C. Lectins labeled with an avidin-biotin fluorescein conjugate was used to visualize a-galactosyl groups on the surface of S. pombe in Fig. 3D. 

Pedini, V., Scocco, P., Dall Aglio, C. and Gargiulo, A.M. (1999) Detection of glycosidic residues in carpal glands of wild and domestic pig revealed by basic and lectin histochemistry. Anat. Anz. 181 (3), 269-274. 

CD31 (54), Factor Vlll-related antigen (55), and CD34 (56) cannot often be demonstrated in poorly differentiated vascular tumors. The use of the lectin Ulex europaeus agglutinin 1 (UEA-1) (57) is a more sensitive method to detect endothelial cells. Like other lectins, however, UFA-1 reacts with many other cell types. 

An ultraviolet (UV) monitor is most commonly used in CE experiment. Such interaction studies using the ACE method can also be hampered by the inadequate sensitivity of UV detection. Fluorescence labeling and laser-induced fluorescence (LIF) detection have been employed to enhance the sensitivity of this method, as shown by the mobility-shift assay of fluorescence-labeled sugar caused by the interaction with the lectin, concanavalin A (74). When fluorescent dyes are employed for labeling, LIF detection provides several hundred times more sensitivity than UV detection. 

Another interesting and recent application of ACE is the fluorescence-enhanced competition assay for the detection of sugar-lectin interactions (77). Because glucose competes with the fluorescently labeled dextran for the lectin-binding sites, the relative fluorescent intensity due to the displaced dextran is proportional to the concentration of glucose. 

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