PROBLEM TO BE SOLVED: To obtain a novel DNA which codes for a protein containing a specific amino acid sequence and having the activity of leucine aminopeptidase originating from a germinated soybean cotyledon and is used for the mass production or the like of an enzyme effectively hydrolyzing a peptide to amino acids. SOLUTION: This DNA is a novel DNA, which codes for a protein containing the amino acid sequence represented by the formula and having the activity of leucine aminopeptidase originating from a germinated soybean cotyledon, and can produce leucine aminopeptidase capable of efficiently hydrolyzing a peptide originating from a soybean protein to amino acid in a high efficiency and large quantity. This DNA is obtained by screening out a cDNA library prepared from germinated soybean cotyledon mRNA by using an already widely known cDNA of leucine aminopeptidase originating from Irish potatoes as a probe.
