title: Studies on neuraminidase from influenza virus A(H3N2) obtained by two procedures.
abstract: 1. Neuraminidase was obtained by (A) bromelain solubilization or (B) by treatment with N-lauroylsarcosine. 2. 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid, employed as substrate, avoids the interference produced by the thiobarbituric acid method, and is not interfered by the ampholytes. 3. Only about 20% of original enzyme activity was lost after electrofocusing. The sample from procedure A showed two peaks, corresponding to pIs 4.4 and 5.6. The sample from procedure B, having a higher activity, showed only one peak at pI 4.4. 4. Samples A and B showed different Km and hydrolysis rate with N-acetylneuraminyl-lactose and glycophorin A. It was not found significantly different with other substrates: alpha 1-acid glycoprotein, brain gangliosides, 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid and 2'-(4-methyl umbelliferyl)-alpha-D-N-acetylneuraminic acid.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D053122:Influenza A Virus, H3N2 Subtype; D009980:Influenza A virus / Q000201:enzymology*; D007525:Isoelectric Focusing; D007700:Kinetics; D008970:Molecular Weight; D009439:Neuraminidase / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D009439:Neuraminidase