Chimerolectins: Classification, structural architecture, and functional perspectives

Lectins are proteins or glycoproteins capable of binding specifically and reversibly to carbohydrates, a property that, in itself, gives them great functional versatility in organisms from all kingdoms of nature. A subclass of these proteins, called chimerolectins, is composed of proteins that have at least one lectin domain associated with another functional domain, such as enzymatic domains or modules involved in molecular signaling processes. The emergence of chimerolectins throughout evolution significantly expanded the functional repertoire of lectins, allowing their action to go beyond the interaction with carbohydrates and glycoconjugates. These proteins are involved in the regulation of the immune system in humans and animals, in the defense of plants against pathogens and predators, as well as in the mediation of responses to biotic and abiotic stresses. In addition, they can act as potent lethal toxins or as factors in the infection of several pathogens and are often associated with the manifestation of symptoms of diseases, which makes them therapeutic targets of great interest. Deepening the structural knowledge of these proteins has been essential for understanding their mechanisms of action, in addition to providing solid bases for biotechnological applications and for the rational development of artificial lectins with specific functions. This approach has enabled the creation of chimerolectins with potent antiviral activity, as well as the development of new therapeutic strategies aimed at inducing death in cells of different tumor lineages.