Uses
This enzyme is 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 enzymatic synthesis of sialic acid.
Uses
Sialic acid aldolase can be used to synthesize unnatural sugars of C(6) to C(10) for the design of antagonists and inhibitors of glycoenzymes.
General Description
Sialic acid aldolases, or N-acetylneuraminate lyases, catalyze the reversible aldol cleavage of N-acetylneuraminic acid to form pyruvate and N-acetyl-D-mannosamine. In nature, N-acetylneuraminate lyase mainly occurs in pathogens.
Purification Methods
Purify the aldolase by extraction with H2O, protamine precipitation, (NH4)2SO4 fractionation, Me2CO precipitation, acid treatment at pH 5.7 and precipitation at pH 4.5. The equilibrium constant for pyruvate + n-acetyl-D-mannosamine N-acetylneuraminidate at 37o is 0.64. The Km for N-acetylneuraminic acid is 3.9mM in phosphate at pH 7.2 and 37o. [Comb & Roseman Methods Enzymol 5 391 1962.] The enzyme from hog kidney (cortex) has been purified 1700-fold by extraction with H2O, protamine sulfate precipitation, (NH4)2SO4 fractionation, heating between 60-80o, a second (NH4)2SO4 fractionation and starch gel electrophoresis. The Km for N-acetylneuraminic acid is 1.5mM. [Brunetti et al. J Biol Chem 237 2447 1962.]
