Description_x000D_ General description_x000D_ Neuraminidase enzymes are glycoside hydrolase enzymes that catalyze hydrolysis of terminal sialic acid residues. The most well-known are the viral nearamidases, which promote influenza virus release._x000D_ Application_x000D_ Neuraminidase from Clostridium perfringens has been used in a study to assess purification via affinity chromatography. It has also been used in a study to investigate site-directed mutations of amino acids of the neuraminidase gene, nanH._x000D_ Biochem/physiol Actions_x000D_ Neuraminidase can block attachment of type 3 reovirus to cell membranes. This effect is related to the ability of neuraminidase to hydrolysis sialic acid residues within cell surface receptors._x000D_ Neuraminidase cleavage of sialic acid groups has been used to study recognition by antibodies of glycoprotein structures. The use of neuraminidase in the estimation of N-acetylneuraminic acid was compared favorably to two other methods._x000D_ Neuraminidases are used to cleave terminal N-acetyl neuraminic acid (sialic acid) from a variety of glycoproteins. The enzyme from Clostridium perfringens cleaves terminal sialic acid residues which are α-2,3- α-2,6- or α-2,8-linked to Gal, GlcNac, GalNAc, AcNeu, GlcNeu, oligosaccharides, glycolipids or glycoproteins. The relative rate of cleavage decreases in the order: α-2-3 > α-2-6 . α-2-8. Neuraminidase from C. perfringens cleaves α-2-3 linked sialic acid residues most efficiently, compared to A. ureafaciens, (Sigma N3642) which preferentially cleaves α-2-6 linked residues._x000D_ The use of neuraminidase to remove sialic acid residues from glycoproteins on cell surfaces has been frequently reported. Generally, procedures have indicated using neuraminidase in PBS at 37°C for 30 minutes, followed by several washings with PBS. Treatment of tissue sections with neuraminidase at much lower concentrations require longer incubation: for 1-4 U/mL in 0.1 M acetate buffer pH 4.2-5, from 2 to 20 hours at 37 °C._x000D_ Unit Definition_x000D_ One unit will hydrolyze 1.0 micromole of 2'-(4-Methylumbelliferyl)-alpha-D-N-actetylneuraminic acid per min at pH 5.0 at 37 °C._x000D_ Preparation Note_x000D_ Purified by affinity chromatography from Type VIII (N 5631)_x000D_ Analysis Note_x000D_ Package sizes based on 4MU-NANA units_x000D_ Package sizes based on the 4MU-NANA units