Carbohydraterecognition

Carbohydraterecognition is the molecular process by which proteins and other molecules detect and bind specific carbohydrate structures, or glycans, that decorate the surfaces of cells, pathogens, and extracellular matrices. This recognition is central to many biological processes, including cell–cell communication, immune surveillance, and host–pathogen interactions. It is mediated by a diverse set of glycan-binding proteins, notably lectins and carbohydrate-binding modules, as well as antibodies and certain receptors that recognize glycan epitopes.

Molecular recognition is typically defined by carbohydrate recognition domains (CRDs) within lectins and related proteins. Binding often depends on the monosaccharide composition, glycosidic linkage, branching pattern, and anomeric configuration of the glycan. Some interactions require calcium or other ions, as in C-type lectins, while others rely on multivalent presentation to achieve high avidity on cell surfaces. The specificity of recognition can be fine-tuned by the geometry of the CRD and the surrounding protein surface.

Biological roles include immune recognition, cell trafficking, and clearance of glycoproteins from circulation. In the immune system, proteins such as DC-SIGN and selectins bind microbial or host glycans to mediate adhesion and signaling; siglecs recognize sialic acid-containing glycans to modulate responses. Glycan recognition also governs development, microbiome interactions, and cancer progression through altered glycosylation patterns on cells and proteins.

Research in carbohydrate recognition employs glycan arrays, mass spectrometry, and structural methods to map binding specificities. Understanding these interactions supports the development of glycan-based vaccines, diagnostic tools, and therapeutic inhibitors that target lectins or glycan epitopes in infectious disease, inflammation, and oncology.