Lectin

Lectin refers to a **large family of proteins**—not a single molecule or receptor—characterized by their ability to bind carbohydrates with high specificity[6][7]. Found in viruses, bacteria, plants, animals, and humans, lectins play diverse roles in cellular recognition, adhesion, and signaling[6][3]. They are structurally categorized based on their **carbohydrate recognition domains (CRDs)** into various families such as C-type, P-type, galectins, and others[1][6]. Biological functions include mediation of immune responses, opsonization, pathogen detection, and cell–cell communication[1][4]. Some lectins are potent toxins (e.g., ricin), while others serve as important biochemical tools, especially in glycoprotein research and diagnostics[7]. As a class, lectins are not considered **therapeutic targets**; individual lectin proteins may be, but "lectins" as a group is a **broad, unspecific target** and thus an incorrect or insufficiently granular entry for targeted drug discovery[6][7]. Caveat: "Lectins" is not a specific molecular target; information should be gathered and analyzed on a per-lectin basis (e.g., C-type lectin receptor, galectin-3), not for the superfamily as a whole[1][6][7].

Other names

Carbohydrate-binding protein

Agglutination of cells by crosslinking glycoproteins/glycolipids; Binding to specific carbohydrate structures, mediating biological recognition or toxic effects (e.g., ricin mechanism)