Novel fructosyl peptide oxidase

A fructosyl peptide oxidase having the following physicochemical properties:

• (a) activity and substrate specificity:
• acts on fructosyl valyl histidine in the presence of oxygen and catalyzes a reaction that produces α-ketoaldehyde, valyl histidine and hydrogen peroxide;
• (b) optimal pH:
• pH 6.0-8.0;
• (c) temperature range suitable for action:
• 20-45° C.;
• (d) thermostability:
• a remaining activity of 80% or higher following a heat treatment at 45° C. for 10 minutes;
• (e) stable pH range:
• pH 6.0-9.0;
• and
• (f) molecular weight:
• about 52,000 (SDS-PAGE).

A protein comprising any one of the following proteins (a), (b) and (c) having a fructosyl peptide oxidase activity:

• (a) a protein comprising an amino acid sequence represented by SEQ ID NO:
• (b) a protein comprising an amino acid sequence having deletion, substitution and/or addition of one to several amino acids relative to the amino acid sequence represented by SEQ ID NO:
• 1, and having a fructosyl peptide oxidase activity;
• and
• (c) a protein comprising an amino acid sequence having 80% or higher homology with the amino acid sequence represented by SEQ ID NO:
• 1, and having a fructosyl peptide oxidase activity.

A gene coding for any one of the following proteins (a), (b) and (c) having a fructosyl peptide oxidase activity:

• (a) a protein comprising an amino acid sequence represented by SEQ ID NO:
• 1;
• (b) a protein comprising an amino acid sequence having deletion, substitution and/or addition of one to several amino acids relative to the amino acid sequence represented by SEQ ID NO:
• 1, and having a fructosyl peptide oxidase activity;
• and
• (c) a protein comprising an amino acid sequence having 80% or higher homology with the amino acid sequence represented by SEQ ID NO:
• 1, and having a fructosyl peptide oxidase activity.

A gene comprising any one of the following DNAs (a), (b) and (c):

• (a) DNA comprising a nucleotide sequence represented by SEQ ID NO:
• 2;
• (b) DNA which hybridizes under stringent conditions with DNA comprising a nucleotide sequence complementary to a full-length or 15 or more consecutive bases of the DNA comprising the nucleotide sequence represented by SEQ ID NO:
• 2, and which codes for a protein having a fructosyl peptide oxidase activity;
• and
• (c) DNA which has 80% or higher homology with a full-length or 15 or more consecutive bases of the DNA comprising the nucleotide sequence represented by SEQ ID NO:
• 2, and which codes for a protein having a fructosyl peptide oxidase activity.

A protein comprising any one of the following proteins (a), (b) and (c) having a fructosyl peptide oxidase activity:

• (a) a protein comprising an amino acid sequence represented by SEQ ID NO:
• 3;
• (b) a protein comprising an amino acid sequence having deletion, substitution and/or addition of one to several amino acids relative to the amino acid sequence represented by SEQ ID NO:
• 3, and having a fructosyl peptide oxidase activity;
• and
• (c) a protein comprising an amino acid sequence having 80% or higher homology with the amino acid sequence represented by SEQ ID NO:
• 3, and having a fructosyl peptide oxidase activity.

A gene coding for any one of the following proteins (a), (b) and (c) having a fructosyl peptide oxidase activity:

• (a) a protein comprising an amino acid sequence represented by SEQ ID NO:
• 3;
• (b) a protein comprising an amino acid sequence having deletion, substitution and/or addition of one to several amino acids relative to the amino acid sequence represented by SEQ ID NO:
• 3, and having a fructosyl peptide oxidase activity;
• and
• (c) a protein having 80% or higher homology with the amino acid sequence represented by SEQ ID NO:
• 3, and having a fructosyl peptide oxidase activity.

A gene comprising any one of the following DNAs (a), (b) and (c):

• (a) DNA comprising a nucleotide sequence represented by SEQ ID NO:
• 4;
• (b) DNA which hybridizes under stringent conditions with DNA comprising a nucleotide sequence complementary to a full-length or 15 or more consecutive bases of the DNA comprising the nucleotide sequence represented by SEQ ID NO:
• 4, and which codes for a protein having a fructosyl peptide oxidase activity;
• and
• (c) DNA which has 80% or higher homology with a full-length or 15 or more consecutive bases of the DNA comprising the nucleotide sequence represented by SEQ ID NO:
• 4, and which codes for a protein having a fructosyl peptide oxidase activity.