Sialic Acid

sialic acid: see glycoprotein.

---

sialic acid [sī′al·ik ′as·əd]

(biochemistry)

Any of a family of amino sugars, containing nine or more carbon atoms, that are nitrogen- and oxygen-substituted acyl derivatives of neuraminic acid; as components of lipids, polysaccharides, and mucoproteins, they are widely distributed in bacteria and in animal tissues.

---

Sialic Acid 

any of the monobasic polyhydroxy amino acids that are derivatives of neuraminic acid. Sialic acids are colorless crystalline solids that dissolve readily in water but are insoluble in nonpolar solvents. They decompose without melting in the temperature range 130°-200°C and are easily decomposed by the action of acids and bases. In nature, as components of glycoproteins and glycolipids, sialic acids are found in, among other places, the cell walls of animals, nerve tissue, and mucous secretions. The biosynthesis of biopolymers containing sialic acids is carried out using the activated form of sialic acids, namely, cytidine monophosphate-sialic acids, which are special sialyltransferase enzymes. Sialic acids determine the antigen and receptor properties of cell surfaces, participating in the interaction of the surfaces with, for example, viruses, toxins, and hormones.