Enzymes for Producing Sialic Acid Kit
Sialic acid is a generic term for the N- or O-substituted derivatives of neuraminic acid, a monosaccharide with a nine-carbon backbone. It is also the name for the most common member of this group, N-acetylneuraminic acid (NANA). Sialic acids are found widely distributed in animal tissues and to a lesser extent in other species ranging from plants and fungi to yeasts and bacteria, mostly in glycoproteins and gangliosides.
The mammalian central nervous system has the highest concentration of sialic acid. The majority (65%) is present in gangliosides and glycoproteins (32%) with the remaining 3% as free sialic acid. The sialic acid moieties of gangliosides and glycoproteins in the frontal cortex play both a structural and functional role and probably participate in a variety of cellular events, such as cell recognition, cell-to-cell contact formation, receptor binding and modulation, immunological properties, and biosignal transduction. Sialic acids also exist in many human body fluids including saliva, gastric juice, serum, urine, tears, and human milk.
Sialic acids play important biological and pathological roles. First, due to their negative charge and hydrophilicity, sialic acids have many structural or physical roles, for example in neural plasticity, glomerular filtration or blood cell charge repulsion. Second, sialic acids serve as components of binding sites for various pathogens and toxins. In most such interactions, a pathogen-binding protein (extrinsic receptor) recognizes certain forms of sialic acids presented in specific linkages to a defined underlying sugar chain. A final class of functions is “molecular mimicry”, in which successful microbial pathogens decorate themselves with sialic acids, assisting in the evasion of host immunity.
Figure 1. Biological and pathological roles of sialic acids. (Varki, A. 2008)
Sialic acid (NANA) assay kit is simple and convenient for measuring free sialic acid (mainly N-acetylneuraminic acid (NANA)) in biological samples. The sialic acid assay uses an enzyme-coupled reaction in which oxidation of free sialic acid creates an intermediate that reacts stoichiometrically with the probe to generate a product that can be detected by absorbance or fluorescence.
Creative Enzymes provides raw materials that can be used to produce sialic acid assay kits, including Neuraminidase (EC 3.2.1.18), N-Acetylneuraminic acid aldolase (EC 4.1.3.3), Lactate dehydrogenase (EC 1.1.1.27).
Neuraminidases (EC 3.2.1.18), also known as sialidase, is a group of glycoside hydrolase enzymes that cleave the glycosidic linkages of neuraminic acids. Neuraminidase enzymes are a large family, found in a range of organisms. The best-known neuraminidase is the viral neuraminidase, a drug target for the prevention of the spread of influenza infection. N-Acetylneuraminic acid aldolase (EC 4.1.3.3) useful for enzymatic determination of N-acetylneuraminic acid and sialic acid when coupled with the related enzymes in clinical analysis. For industrial use, this enzyme is useful for the enzymatic synthesis of sialic acid. Lactate dehydrogenase (EC 1.1.1.27), also known as NAD+ oxidase, catalyzes the reversible conversion of pyruvate and L-lactic acid and is an important oxidoreductase in the process of glycolysis, which is widely found in animal tissues and various microbial cells.
References
- Varki A. Sialic acids in human health and disease[J]. Trends in Molecular Medicine, 2008, 14(8):351-360.
- Wang B., Brand-Miller J. The role and potential of sialic acid in human nutrition[J]. European Journal of Clinical Nutrition, 2003, 57(11):1351-1369.
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