Purification and characterization of a sialidase from Bacteroides fragilis SBT3182.
A sialidase from Bacteroides fragilis SBT3182 was purified 2,240-fold to apparent homogeneity by ammonium sulfate precipitation and sequential chromatographies on DEAE-Toyopearl 650M, Hydroxyapatite, MonoS and Superose6 columns. The N-terminal amino acid sequence of this sialidase, Ala-Asp-X-Ile-Phe-Val-Arg-Glu-Thr-Arg-Ile-Pro-, was determined. Substrate specificity of this enzyme using a variety of sialoglycoconjugates showed a 1.5- and 2.2-fold preference for sialyl alpha 2-8 linkages when compared with alpha 2-3 and alpha 2-6 bound sialic acids, respectively. The native sialidase had a molecular weight of 165kDa, as determined by Superose6 gel filtration chromatography and consisted of three subunits each of 55kDa by SDS-polyacrylamide gel electrophoresis. This enzyme had optimal activity at pH6.1 with colominic acid as substrate.
Tanaka
H
H
Technical Research Institute, Snow Brand Milk Products Co., Ltd., Saitama, Japan.
Ito
F
F
Iwasaki
T
T
D000595:Amino Acid Sequence; D001441:Bacteroides fragilis / Q000201:enzymology*; D002240:Carbohydrate Sequence; D002845:Chromatography; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017886:Durapatite; D006882:Hydroxyapatites; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009439:Neuraminidase / Q000302:isolation & purification* / Q000378:metabolism*; D013379:Substrate Specificity
D006882:Hydroxyapatites; D017886:Durapatite; D009439:Neuraminidase