Lectins

Abstract Lectins, a class of sugar‐specific and cell‐agglutinating proteins of nonimmune origin that are devoid of enzymatic activity, are ubiquitous in nature. Plant lectins are invaluable tools for the study of carbohydrates, in solution and on cells, and are also employed for purging of bone marrow for transplantation into ‘bubble children’. Bacterial cell surface lectins mediate the attachment of the organisms to host cell surfaces in the initiation of infection; their blocking by suitable sugars can serve as a basis of antiadhesion therapy of bacterial diseases. Those of animals control the biosynthesis of glycoproteins, play key roles in cell interactions in the immune system and serve as innate immunity agents against microbial pathogens. They also monitor the migration of leucocytes in blood vessels and contribute to proliferation and metastasis of tumour cells. Key concepts: Antiadhesion therapy Carbohydrate specificity Cell recognition Circular homology Glycoarrays; lectin arrays Lectin replacement therapy Surface carbohydrates Multisubunit proteins