2. Academic Validation
  3. D-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities

D-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities

  • Sci Rep. 2025 Jul 14;15(1):25415. doi: 10.1038/s41598-025-10379-2.
Mayu Onozato 1,  Tomoya Takaura 2,  Wataru Shinohara 3,  Takehiro Tsukada 4,  Tatsuya Sakamoto 2,  Kenji Okoshi 5 6,  Takeshi Fukushima 2
Affiliations

Affiliations

  • 1 Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, 274-8510, Chiba, Japan. [email protected].
  • 2 Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, 274-8510, Chiba, Japan.
  • 3 Chiba Municipal Chiba High School, 9-46-1 Konakadai, Inage-ku, Chiba-shi, 263-0043, Chiba, Japan.
  • 4 Department of Biomolecular Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi-shi, 274-8510, Chiba, Japan.
  • 5 Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi-shi, 274-8510, Chiba, Japan.
  • 6 Toyo Institute of Food Technology, 4-23-2 Minami-Hanayashiki, Kawanishi-shi, 666-0026, Hyogo, Japan.
PMID: 40659749 DOI: 10.1038/s41598-025-10379-2
Abstract

Amino acids play essential roles in various biological processes. In humans, most Amino acids are present in the L-form; however, small amounts of D-amino acids also exist and have significant physiological roles, highlighting the importance of dietary intake from foods or drinks. In this study, we investigated the amino acid composition of the geoduck clam Panopea japonica, emphasizing its remarkably high D-alanine (D-Ala) content in the siphon tissue. The D-Ala content (6.99-14.2 mmol/100 g-wet) amounted to 91-94% of the total Ala, far exceeding that of Other bivalves such as Tresus keenae (74%). Enzyme assays revealed alanine racemase and D-amino acid oxidase activities, suggesting active D-Ala biosynthesis and metabolism. The high concentrations of D-Ala enhance its value as a delicacy owing to its unique sweetness. This study provides new insights into the biosynthesis and metabolic characteristics of D-Ala in bivalves, highlighting its physiological and food ingredient significance.

Keywords

d-Alanine; d-amino acid oxidase; Alanine racemase; Amino acid; Bivalve; LC-MS/MS; Siphon.

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