Metabolism of sialic acids

Corfleld AP, Schauer R (1982) Metabolism of sialic acids. In Schauer R (ed) Sialic acids - Chemistry, metabolism and function. Springer, Wien, pp 195-261 Corfleld AP, Higa H, Paulson JC, Schauer R (1983) The specificity of viral and bacterial sial-idases for alpha(2-3)- and alpha(2-6)-linked sialic acids in glycoproteins. Biochim Biophys Acta 744 121-126... 

C. Traving and R. Schauer, Structure, function and metabolism of sialic acids, Cell. Mol. Life Sci., 54 (1998) 1330-1349. 

Little is known of any regidation of the metabolism of sialic acid on a level higher than the enzymic level just described. The few experiments performed with animals point to an influence exerted by hormones. Thus, increase of the synthesis of sialoglycoeonjugate (mucus) has been described as occurring in mouse vaginal-epithelium under the influence of estrogen.240 Similarly, insulin therapy restored the sialic acid content of rat hepatocyte-membrane which was decreased in streptozotocin-induced diabetes.241... 

Nonphysiological compounds have also been described as influencing the overall metabolism of sialic acid. Administration of ethanol (2 g/kg) to rats significantly decreases the sialic acid content of brain tissue.246 Convulsions induced by pentylenetetrazole (6,7,8,9-tetrahy-dro-5/f-tetrazoloazepine) are accompanied by a diminution in the rate of biosynthesis of polysialogangliosicles GT, and GQn, in rat brain.227 Such ManNAc analogs as 2-acetamido-l,3,4,6-tetra-0-acetyl-2-deoxy-D-mannopyranose or the 2-(trifluoroacetamido) derivative lead to a marked lowering of the incorporation of radioactivity from labelled ManNAc into glycoconjugate sialic acids of murine, erythroleukemia (Friend) cells.247... 

The aldolases which have been investigated for their synthetic utility can be classified on the basis of the donor substrate accepted by the enzyme. For the synthesis of 3-deoxy-2-ulosonic acids pyruvate- and phosphoenolpyruvate dependent aldolases are the most desirable enzymes as they are involved in the metabolism of sialic acids (or structurally related ones) in vivo. They use pyruvate or phosphoenolpyruvate as a donor to form 3-deoxy-2-keto acids (Table 1). Both of them add a three-carbons ketone fragment onto a carbonyl group of an aldehyde. The pyruvate dependent aldolases have a catabolic function in vivo, whereas the phosphoenolpyruvate dependent aldolases are involved in the biosynthesis of the keto acids. For synthetic purpose the equilibrium of the pyruvate dependent aldolases is shifted toward the condensation products through the use of an excess of pyruvate. 

One of the latest volumes in the series International Review of Science covers the isolation and structures of glycoproteins from ovarian cysts, gastric mucosa, submaxilliary glands, and erythrocytes. Physical and chemical data have been compiled for glycoproteins. Other reviews have discussed the chemistry, occurrence, and metabolism of sialic acids, with reference to cell-surface neuraminidases and the metabolism of molecules containing residues of sialic acid by cells transformed with tumourigenic viruses, and the effects of neuraminidases on intermolecular and intercellular forces. ... 

Metabolism of Sialic Acids different sources. A selection from the literature... 

Maintenance of pregnancy, i.e. maternal tolerance to foreign tissue of the fetus, calls for crucial immunological adaptations, which also involve the metabolism of sialic acid. Endocrinologically controlled changes in sialic acid content of the cervical mucus of the uterus during the menstrual cycle are of... 

Corfield, A.P., and Schauer, R. Metabolism of sialic acids. In Sialic Acids—Chemistry, Metabolism and Function (Schauer, R., ed.) (1982) Springer Wien, New York, pp. 195-261. 

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