Literature References: High molecular weight glycoproteins, major constituents of saliva, gastric juice, intestinal juice, and other secretions: F. Haurowitz, Chemistry and Biology of Proteins (Academic Press, New York, 1950) p 199. Mucins are capable of forming viscous solutions and thereby act as lubricants or protectants in cavities of the body or on body surfaces. For prepn (e.g. from snails) and their biochemical role see P. A. Levene, The Hexosamines and Mucoproteins (Longmans, Green, London, 1925). Ovine submaxillary mucin consists of a single polypeptide chain with about 800 disaccharide units attached, each of which is N-acetylneuraminyl(2®6) N-acetylgalactosamine. Carbohydrate accounts for about 45% of the molecular weight. Structure studies: Pigman, Tanaka, 148th Am. Chem. Soc. Meet. (Chicago, Aug.-Sept., 1964), Abstracts of Papers, p 11C; Ozeki, Yosizawa, Arch. Biochem. Biophys. 142, 177 (1971); Huser et al., Z. Physiol. Chem. 354, 749 (1973). Glycoproteins in bovine cervical mucus: F. A. Meyer et al., Adv. Exp. Med. Biol. 89, 239 (1977). Review on physical and chemical properties, biosynthesis and function of mucin: several authors in Mucus in Health and Disease, M. Elstein, D. V. Parke, Eds. (Plenum Press, New York, 1977) pp 171-311.
Properties: Mucins are obtained as greenish-gray or yellow powders forming very viscous solns in water; generally sol in dil alkalies. Insol in acetic acid. Acidic substances with an isoelectric point between pH 3 and 5.
Use: Demulcent; adsorbent.