Studies on the Accumulation Mechanism and Metabolism of D-Alanine in Aquatic Animals

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 10660193
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Fisheries chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: WATANABE Katsuko Grad. School Agr. Life Sci. THE UNIVERSITY OF TOKYO Instructor, 大学院・農学生命科学研究科, 助手 (30092381)
• Project Period (FY): 1998 – 2000
• Keywords: aquaqtic animal / D-amino acid / D-alanine / alanine racemase / Mollusca

Research Abstract

Recent investigations show rather wide distribution of some D-amino acids in marine animals. The present studies were planned to accumulate more information on the distribution of D-enantiomer of alanine in aquatic animals.
No measurable D-alanine could be detected in Periphery, Coelenterata, Platyhelminthes, Nemertinea and Prochordata species. D-Alanine-containing species belong to the order Archaegastropoda and Mesogastropoda, the subclass Eulamellbranchia in the phyla, Mollusca, the order Decapoda in the phyla Arthropoda and the subclass Euechinoidea in the phyla Echinodermata and D-alanine lacking species to the order Neogastropoda, the subclass Pteriomorphia and the class Cephalopoda in the phyla Mollusca, the order thoracica and Isopoda in the phyla Arthropoda, the class Euasteroidea and Holothuroidea in the phyla Echinodermata.
Crude supernatant from tissues of Haliotis diversi color diversicolor, turban shell, Tectus maximus, Manoplex echo, Charonia sauliae sauliae, Rapana venosa, common octopus, Japanese common squid and ocellate puffer was examined for alanine racemase activity in both direction (D-alanine to L-alanine and L-alanine to D-alanine). The activity in mid gut glad of T.maximus was 21.3 μmol of product formed g wet tissue/h in the L-to-D direction and 26.3 in the D-to-L direction. In many tissues of the other species in Gastropoda except R.venosa alanine racemase activity occurs in both direction. Alanine racemase activity in the only D-to-L direction is found in liver and kidney of common octopus, Japanese common squid and ocellate puffer, which are D-alanine-lacking species (only L-alanine is present).