| 摘要 |
PURPOSE:To obtain an endosialidase, derived from a bacteriophage using Escherichia coli having a K1 antigen as a host, useful for obtaining sialic acid trimer from colominic acid, having heat resistance and capable of preventing the reactional system from being contaminated with various germs during the reaction. CONSTITUTION:This bacteriophage is obtained by isolating a bacteriophage from sewage using Escherichia coli K1 as a host, fractionating a lytic so,lution of the bacteriophage with ammonium sulfate, heat-treating the fractionated bacteriophage, then purifying the resultant fraction according to a hydrophobic chromatography and an ion exchange chromatography and providing an endosialidase derived from the bacteriophage. The bacteriophage and endosialidase are capable of recognizing an alpha-2,8-silic acid tetramer or its lower oligomers as a substrate and hydrolyzing the tetramer into the sialic acid monomer and its trimer. The hydrolysis is carried out at 50-80 deg.C. |
