Mutant glycine oxidase derived from thermophilic bacterium belonging to family bacillus, and method for producing same

A mutant glycine oxidase

• which is a mutant enzyme in which a glycine at the 251st position of an amino acid sequence having at least 95% sequence identity to SEQ ID NO:
• 1, in an amino acid motif of asparagine (N), glycine (G), cysteine (C), and tyrosine (Y), of a wild-type glycine oxidase derived from thermophilic bacteria selected from a group consisting of Geobacillus kaustophilus, Geobacillus stearothermophilus, and Geobacillus thermoleovorans is substituted with another amino acid, the mutant glycine oxidase having:
• a molecular weight of 40,000±2,000 daltons in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE);
• an optimum temperature of 45° C. under a condition of pH 8.5 in presence of pyrophosphate;
• an optimum pH of pH 8.0 under a condition of 37° C. in presence of pyrophosphate;
• a thermal stability being stable up to 70° C. under a condition of pH 8.5 while retaining for 1 hour in presence of pyrophosphate;
• a pH stability being stable in a range of pH 5.5 to 10.0 under a condition of 4° C. while retaining for 24 hours in presence of pyrophosphate;
• a specific activity of at least 1.2 units/mg;
• and
• a kinetic constant (Michaelis constant) Km of 0.2 mM or less.