Mucin-2/MUC2 Protein, Human (His)

MUC2 is a mucin that coats the epithelia of the intestines and other mucus membrane-containing organs, providing a protective and lubricating barrier against particles and infectious agents at mucosal surfaces. As the major constituent of colon mucus, it forms large polymeric networks secreted by goblet cells, covering the intestinal surfaces. These networks create hydrogels that shield the underlying epithelium from pathogens and hazardous materials while enabling nutrient absorption and gas exchange. MUC2 also acts as a divalent copper chaperone, protecting intestinal cells from copper toxicity and facilitating nutritional copper uptake. It binds both Cu²⁺ and Cu(1+) at adjacent sites, with Cu²⁺ reduced to Cu(1+) by vitamin C or dietary antioxidants, allowing its release for cellular uptake. Additionally, MUC2 gels store antimicrobial molecules for innate immunity, support the microbiome, lubricate tissues, and aid in waste removal. By similarity, goblet cells produce two forms of MUC2: a 'thick' mucus in the proximal colon that encases microbiota to form fecal pellets, and a 'thin' mucus in the distal colon that adheres to and lubricates the 'thick' mucus as it moves through the descending colon.