| 摘要 |
PURPOSE: To obtain the new enzyme, derived from a microorganism of the genus Sulfolobus, capable of providing a nonreducing glucide having the trehalose structure at the terminal from a reducing starch sugar. having an elegant sweetness without causing coloring or discoloring and useful for foods, drinks, cosmetics, medicines, etc. CONSTITUTION: This new recombinant type thermostable enzyme is derived from a microorganism of the genus Sulfolobus, has an amino acid sequence from the N- terminal including an amino acid represented by the formula or an amino acid sequence homologous therewith, has functions to produce a nonreducing glucide having the trehalose structure from a reducing starch sugar having >=3 polymerization degree, is capable of manifesting about 69000-79000Da molecular weight obtained by the measurement according to the sodium dodecyl sulfate(SDS)-polyacrylamide gel electrophoresis and about 5.4-6.4 isoelectric point obtained by the measurement according to the isoelectric focusing without being inactivated even by incubation at 85 deg.C in an aqueous solution (at pH7.0) for 60min. The enzyme is obtained by integrating a cloned enzymic gene derived from a microorganism of the genus Sulfolobus into a plasmid vector and expressing the gene in a host. |
