Transglycosylation method and protein having transglycosylation activity

A method of modifying a food,

• wherein the food before modification contains a sugar chain acceptor selected from the group consisting of a monosaccharide, an oligosaccharide, an alcohol (1-alkanol), an amino acid and a polypeptide,
• the method comprising a reaction of transferring a galactosyl β1→3N-acetylgalactosaminyl group from a sugar donor containing a sugar chain having a galactosylβ1→3N-acetylgalactosaminyl group bound thereto at the α-position, to the sugar chain acceptor, in the presence of a protein having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity.

A method of modifying a drug,

• wherein the drug before modification contains a sugar chain acceptor selected from the group consisting of a monosaccharide, an oligosaccharide, an alcohol (1-alkanol), an amino acid and a polypeptide,
• the method comprising a reaction of transferring a galactosylβ1→3N-acetylgalactosaminyl group from a sugar donor containing a sugar chain having a galactosylβ1→3N-acetylgalactosaminyl group bound thereto at the α-position, to the sugar chain acceptor, in the presence of a protein having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity.

A protein derived from a microorganism belonging to the genus Bifidobacterium and having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity.

A protein selected from the group consisting of (A) and (B):

• (A) a protein having an amino acid sequence described in SEQ ID NO:2, and
• (B) a protein having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity, and having the amino acid sequence that includes one or several amino acids mutation in the amino acid sequence described in SEQ ID NO:
• 2, the mutation being selected from the group consisting of substitution, deletion, insertion, addition, and inversion.

A polynucleotide encoding a protein selected from the group consisting of (A) and (B):

• (A) a protein having an amino acid sequence shown in SEQ ID NO:2, and
• (B) a protein having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity, and having the amino acid sequence that includes one or several amino acids mutation in the amino acid sequence described in SEQ ID NO:
• 2, the mutation being selected from the group consisting of substitution, deletion, insertion, addition, and inversion.

A polynucleotide selected from the group consisting of (a) and (b):

• (a) a polynucleotide consisting of a nucleotide sequence shown in SEQ ID NO:1, and
• (b) a polynucleotide which hybridizes under stringent conditions with a polynucleotide consisting of a nucleotide sequence complementary to a nucleotide sequence shown in SEQ ID NO:
• 1, and which encodes a protein having an endo-α-N-acetylgalactosaminidase activity and a transglycosylation activity.