Document Detail


Distribution of free D-aspartic acid and D-aspartate oxidase in frog Rana esculenta tissues.
MedLine Citation:
PMID:  20108220     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In this paper, we examined the distribution pattern of D-aspartic acid (D-Asp), as well as D-aspartate oxidase (D-AspO), D-amino acid oxidase (D-AAO), and L-amino acid oxidase (L-AAO) activities in different tissues of frog, Rana esculenta. High concentrations of free D-Asp were found in the testes (0.21+/-0.02 micromol/g b.w), in the liver (0.20+/-0.03 micromol/g b.w), and in the Harderian gland (HG) (0.19+/-0.03 micromol/g b.w). A higher activity of both D-AspO and D-AAO with respect to L-AAO was endogenously present in all examined frog tissues, particularly within the kidney, liver, and brain. Our in vivo experiments, consisting of i.p. injections of 2.0 micromol/g b.w. D-Asp in frogs, revealed that all examined tissues can take up and accumulate D-Asp and that this amino acid specifically triggers D-AspO activity. Indeed, no increase in both D-AAO and L-AAO was found in all frog tissues after D-Asp treatment. The optimum pH for D-AspO activity was around 8.2 and the optimum temperature was about 37 degrees C. Furthermore, its activity linearly increased with increasing D-Asp incubation times. In vitro experiments assaying the substrate specificity of D-AspO indicated that the enzyme had greater affinity for N-methyl-D-aspartate than for D-Asp and D-glutamate. This study provides evidence of the presence of free D-Asp in frog R. esculenta tissues, along with its role in triggering D-AspO activity. These findings suggest that D-AspO could play an essential role in decreasing excessive amounts of D-Asp in frog tissues, a phenomenon that, if left unchecked, could have detrimental physiological effects on the animal.
Authors:
Marcello Di Giovanni; Lavinia Burrone; Gabriella Chieffi Baccari; Enza Topo; Alessandra Santillo
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of experimental zoology. Part A, Ecological genetics and physiology     Volume:  313     ISSN:  1932-5231     ISO Abbreviation:  J Exp Zool A Ecol Genet Physiol     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-04-07     Completed Date:  2010-07-12     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101297745     Medline TA:  J Exp Zool A Ecol Genet Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  137-43     Citation Subset:  IM    
Affiliation:
Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, via Vivaldi, Caserta, Italy. marcello.digiovanni@unina2.it
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MeSH Terms
Descriptor/Qualifier:
Animals
Brain / enzymology
D-Aspartate Oxidase / metabolism*
D-Aspartic Acid / metabolism*
Kidney / enzymology
Liver / enzymology
Male
Rana esculenta
Chemical
Reg. No./Substance:
1783-96-6/D-Aspartic Acid; EC 1.4.3.1/D-Aspartate Oxidase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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