Functions in nature

Abstract

The ubiquitous occurrence of lectins in nature and their ability to discriminate between closely related saccharides in solution and on cell surfaces provided a major stimulus for the continuing search for their physiological function(s). A strong argument that lectins indeed have such functions is the fact that they have been conserved throughout evolution as homologous families of proteins. Another argument is that many of them are developmentally regulated and that their appearance often coincides with a distinct physiological change in the life of an organism. Notably, the putative receptors for the lectins, i.e. complementary carbohydrate structures, are frequently also under strict developmental control.