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

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 s...

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Main Authors: Mayu Onozato, Tomoya Takaura, Wataru Shinohara, Takehiro Tsukada, Tatsuya Sakamoto, Kenji Okoshi, Takeshi Fukushima
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-10379-2
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author Mayu Onozato
Tomoya Takaura
Wataru Shinohara
Takehiro Tsukada
Tatsuya Sakamoto
Kenji Okoshi
Takeshi Fukushima
author_facet Mayu Onozato
Tomoya Takaura
Wataru Shinohara
Takehiro Tsukada
Tatsuya Sakamoto
Kenji Okoshi
Takeshi Fukushima
author_sort Mayu Onozato
collection DOAJ
description 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.
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issn 2045-2322
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publishDate 2025-07-01
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series Scientific Reports
spelling doaj-art-ddbe0aaff7f94ff29e4d63e6830fc8d62025-08-20T04:02:45ZengNature PortfolioScientific Reports2045-23222025-07-0115111010.1038/s41598-025-10379-2d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activitiesMayu Onozato0Tomoya Takaura1Wataru Shinohara2Takehiro Tsukada3Tatsuya Sakamoto4Kenji Okoshi5Takeshi Fukushima6Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho UniversityDepartment of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho UniversityChiba Municipal Chiba High SchoolDepartment of Biomolecular Science, Faculty of Science, Toho UniversityDepartment of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho UniversityDepartment of Environmental Science, Faculty of Science, Toho UniversityDepartment of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho UniversityAbstract 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.https://doi.org/10.1038/s41598-025-10379-2d-AlanineBivalveAmino acidSiphonAlanine racemased-amino acid oxidase
spellingShingle Mayu Onozato
Tomoya Takaura
Wataru Shinohara
Takehiro Tsukada
Tatsuya Sakamoto
Kenji Okoshi
Takeshi Fukushima
d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
Scientific Reports
d-Alanine
Bivalve
Amino acid
Siphon
Alanine racemase
d-amino acid oxidase
title d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
title_full d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
title_fullStr d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
title_full_unstemmed d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
title_short d-Alanine content in the marine edible bivalve Panopea japonica and evaluation of its associated enzyme activities
title_sort d alanine content in the marine edible bivalve panopea japonica and evaluation of its associated enzyme activities
topic d-Alanine
Bivalve
Amino acid
Siphon
Alanine racemase
d-amino acid oxidase
url https://doi.org/10.1038/s41598-025-10379-2
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