Abstract: Disclosed is a polypeptide shown in the following in (A), and a protein dimer neoculin comprising the polypeptide Neoculin Acidic Subunit (NAS) and the polypeptide Neoculin Basic Subunit (NBS) and having a taste-modifying activity: (A) a polypeptide comprising an amino acid sequence shown in SEQ ID NO.2 in the sequence listing.

Abstract: Disclosed is a polypeptide shown below in (A) or (B), a protein dimer neoculin comprising the polypeptide Neoculin Acidic Subunit (NAS) and the polypeptide Neoculin Basic Subunit (NBS) and having a taste-modifying activity: (A) a polypeptide comprising an amino acid sequence shown in SEQ ID NO.2 in the sequence listing; (B) a polypeptide comprising an amino acid sequence with the substitution, deletion, insertion, addition or inversion of one or several amino acids in the amino acid sequence shown in SEQ ID NO. 2 in the sequence listing, which polypeptide can form the neoculin dimer having a taste-modifying activity together with the polypeptide NBS.

Abstract: It is an object of the invention to find a substance with a better taste-modifying function and determine the structure of the taste-modifying substance, as well as to elucidate the structure thereof at a gene level and determine the primary structure of the substance and obtain the gene encoding the substance. Additionally, it is an object of the invention to provide a novel taste-modifying composition characteristically containing the taste-modifying substance. Specifically, the invention provides the polypeptide shown below in (A) or (B), a protein dimer neoculin comprising the polypeptide NAS and the polypeptide NBS and having a taste-modifying activity: (A) a polypeptide comprising an amino acid sequence shown in SEQ ID NO.2 in the sequence listing; (B) a polypeptide comprising an amino acid sequence with the substitution, deletion, insertion, addition or inversion of one or several amino acids in the amino acid sequence shown in SEQ ID NO.