Lectins carbohydrate specificity determination

Many unanswered questions remain with respect to the lentil lectins. These include the chemical relationship between the two lectins, a comparison of their carbohydrate-binding specificity, a study of the binding of furanoid sugars (for example, a- and /3-arabinofuranosides) to the lectins, and a determination of the H or O atoms of each hydroxyl group which may be involved in the binding phenomenon. There is also the question as to the size of the binding site will the lentil-lectin site be more complementary to sequences of a-D-(l— 2)-mannopyranosyl residues than is con A (compare Ref. 204) ... 

Purification of Lectins and Determination of Their Carbohydrate Specificity... 

Finally, an interesting example has been reported in the syntheses of new photoreactive neoglycolipid probes carrying carbohydrate determinants specific for some murine mammary adenocarcinoma cells for the study of lectin receptors on tumor cell surfaces.71... 

Due to the vast amount of recent research on lectins, it is quite apparent that proteins which bind to specific cell-surface glycoproteins are involved in modulation of a variety of mitotic and metabolic events within the cell. It is hoped that structural studies of these proteins and their receptors will prove to be informative in determining the mechanisms of these and other such events. In this presentation, I would like to discuss the structural features of Con A, such as the /3-sheets, subunit structure, the manganese, calcium and carbohydrate binding sites and close, by mentioning some recent advances in crystallography which are relevant to the studies of proteins and how these should effect such future research. 

The data presented here demonstrate that lectins may be used to explore structural aspects of the carbohydrate moieties of specific cell surface bound antigens. Furthermore, it is suggested that the H-2D antigen possesses differences in the structure of the carbohydrate moieties which may reflect microheterogeneity due to the biosynthesis of only partial structures, differences in the number of sialic acid residues, the relationship of the carbohydrate chains to the specific antigenic determinants and/or major structural differences of the carbohydrate chains on different H—2D antigens. 

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