N- acetylneuraminic acid NEW

N-acetylneuramic acid is the most widely distributed sialic acid (N-acylneuramic acid) in nature, which is mainly the constituent sugar of animal cell membrane or secretory fluid glycoprotein, glycolipid or bacterial capsule substance. In a glycoprotein or glycolipid, it is located at the non-reducing end of the sugar side chain due to the formation of a glycosidic bond by the keto group at position 2, and its negative charge or unique chemical structure gives it various physiological specificities. Enzymes that hydrolyze and remove terminal N-acetylneuraminidase (neuraminidase) are widely distributed in nature, from viruses to animals. The role of this terminal acid sugar residue has been identified by treating the physiological changes in the activity of this enzyme. For example, this glycoresidue forms the binding site of the influenza virus in the cell membrane of the red blood cell and plays a major role in the mutual recognition of plasma glycoproteins and liver cells or in the recognition mechanism of circulatory pathways by lymphocytes. The biosynthetic pathways are somewhat different in animals and bacteria, but they all go through n-acetylmannosamine or its 6-phosphate ester, which is catalyzed by a specific pyrophosphatase and reacts with CTP to produce CMP-N-acetylneuramic acid, which is then incorporated into the sugar chain by glycosylation.

N-acetylneuramic is a carbohydrate widely found in nature and is a fundamental component of many glycoproteins, glycopeptides, and glycolipids. It has a wide range of biological functions, such as regulation of the half-life of blood proteins, neutralization of various toxins, cell adhesion, antigen-antibody response of immunity, and protection against cell lysis. Biochemical derivatives of N-acetylneuramic are also commonly used in the synthesis of drugs.