The present invention provides modified tamabidin 2, which is a modified biotin-binding protein comprising an amino acid sequence represented by SEQ ID NO: 2, an amino acid sequence having one or more amino acid mutations in the amino acid sequence of SEQ ID NO: 2, or an amino acid sequence having an identity of not less than 80% to the amino acid sequence of SEQ ID NO: 2 and having biotin-binding activity, wherein an asparagine residue at position 115 of SEQ ID NO: 2 is replaced with cysteine. The modified biotin-binding protein has remarkable heat resistance.
