Enzyme Specificity | - This enzyme preferentially releases a(2-3)-linked N-acetylneuraminic acid (Neu5Ac, NANA) from complex carbohydrates. Sialidase S is also active against a(2-3)-linked N-glycolyneuraminic acid [1] (Neu5Gc, NGNA), although similarly to other sialidases [2] the activity is lower toward Neu5Gc than Neu5Ac. Although the a(2-3)-linkage is preferred, Sialidase S (also known as NanB) is also capable of cleaving a(2-6)-linked sialic acid [3], particularly at higher concentrations. Adding an excess of this enzyme can lead to some cleavage of a(2-6)-linked sialic acid. Using GK80021 as directed in the certificate of analysis reduces the likelihood of these effects. Users may wish to optimize the enzyme concentration needed for specific proteins. May be used for exoglycosidase sequencing with Sialidase A (GK80040), which has a broader specificity, releasing a(2-3,6,8,9)-linked sialic acids. Sialidases are also known as neuraminidases.
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