Intestinal mucosal glycoprotein (MUC)

Intestinal epithelial cell surface and mucosal glycoproteins, primarily represented by the mucin family (e.g., MUC2), are large, heavily O-glycosylated proteins that form the essential protective interface between the intestinal lumen and the host tissue (NCBI: PMC3708563). These glycoproteins exist in two main forms: membrane-bound proteins that constitute the glycocalyx and secreted proteins that polymerize into a viscous mucus gel (UniProt: Q02817). Their primary biological function is to provide a physical and chemical barrier against mechanical damage, gastric acid, digestive enzymes, and enteric pathogens, while also facilitating the transport of nutrients and lubricating the passage of luminal contents (NCBI: PMC3708563). In pathological states such as peptic ulcer disease or inflammatory bowel disease (IBD), the integrity of this glycoprotein layer is often diminished, leading to increased mucosal permeability and inflammation (PubMed: 23609496). Therapeutic agents known as mucosal protectants, such as sucralfate and bismuth subsalicylate, target these glycoproteins by binding to them—especially at sites of tissue injury—to form a protective barrier that shields the underlying epithelium and promotes endogenous repair mechanisms (PubChem: CID 6398; StatPearls: NBK537071).

Other names

Intestinal epithelial cell surface/mucosal glycoproteinsMucinGastrointestinal mucinGlycocalyxIntestinal mucus layerMUC proteinsBrush border glycoproteins

Formation of a protective physical barrier by binding to glycoproteins; stimulation of endogenous mucus and bicarbonate secretion; inhibition of pepsin-mediated mucosal degradation.