Sialidase of swine influenza A viruses: variation of the recognition specificities for sialyl linkages and for the molecular species of sialic acid with the year of isolation.
The sialidase of swine influenza A viruses of N1 and N2 subtypes, isolated from 1930 to 1992, was studied for substrate specificity with ganglio-series, lacto-series type II and GM3 gangliosides containing Neu5Ac alpha 2-3Gal, Neu5Gc alpha 2-3Gal and Neu5Ac alpha 2-6Gal linkages. All viral sialidases tested showed that the activity for hydrolysing substrates with Neu5Ac alpha 2-3Gal was higher than the activities with Neu5Gc alpha 2-3Gal and Neu5Ac alpha 2-6Gal linkages. When GM1b, GM3 and sialylparagloboside were used as substrates, the earliest strain (A/Wisconsin/15/30 H1N1, isolated in 1930) showed the activity ratio of Neu5Ac alpha 2-6Gal to Neu5Ac alpha 2-3Gal to be 0.13:0.2, and the ratio Neu5Gc alpha 2-3Gal/Neu5Ac alpha 2-3Gal to be 0.19:0.37, while those strains isolated from 1978 to 1992 exhibited ratios of 0.29:0.58 for Neu5Ac alpha 2-6Gal/Neu5Ac alpha 2-3Gal and 0.51:0.76 for Neu5Gc alpha 2-3Gal/Neu5Ac alpha 2-3Gal. The above results indicate that the substrate specificities of sialidases from swine influenza A viruses towards sialyl linkages and the molecular species of sialic acid are related to the year of isolation, i.e. strains isolated after 1978 exhibited higher activity towards Neu5Ac alpha 2-6Gal and Neu5Gc alpha 2-3Gal linkages when compared with strains isolated in an earlier year, 1930.
Xu
G
G
Department of Biochemistry, University of Shizuoka, School of Pharmaceutical Science, Japan.
Suzuki
T
T
Maejima
Y
Y
Mizoguchi
T
T
Tsuchiya
M
M
Kiso
M
M
Hasegawa
A
A
Suzuki
Y
Y
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005732:Gangliosides / Q000737:chemistry / Q000378:metabolism; D009980:Influenza A virus / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D009439:Neuraminidase / Q000378:metabolism*; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
D005732:Gangliosides; D012794:Sialic Acids; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid