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Titolo:
Domoic acid binds iron and copper: a possible role for the toxin produced by the marine diatom Pseudo-nitzschia
Autore:
Rue, E; Bruland, K;
Indirizzi:
Univ Calif Santa Cruz, Dept Ocean Sci, Santa Cruz, CA 95064 USA Univ CalifSanta Cruz Santa Cruz CA USA 95064 i, Santa Cruz, CA 95064 USA
Titolo Testata:
MARINE CHEMISTRY
fascicolo: 1-2, volume: 76, anno: 2001,
pagine: 127 - 134
SICI:
0304-4203(200110)76:1-2<127:DABIAC>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
CATHODIC STRIPPING VOLTAMMETRY; NATURAL ORGANIC-LIGANDS; BLUE-GREEN; POSSIBLE PHYTOSIDEROPHORE; HYDROXAMATE-SIDEROPHORE; ATLANTIC-OCEAN; NORTH PACIFIC; MUGINEIC ACID; COMPLEXATION; SEAWATER;
Keywords:
harmful algal species; domoic acid; iron and copper biological availability;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Physical, Chemical & Earth Sciences
Citazioni:
55
Recensione:
Indirizzi per estratti:
Indirizzo: Bruland, K Univ Calif Santa Cruz, Dept Ocean Sci, 1156 High St, Santa Cruz, CA 95064 USA Univ Calif Santa Cruz 1156 High St Santa Cruz CA USA 95064 USA
Citazione:
E. Rue e K. Bruland, "Domoic acid binds iron and copper: a possible role for the toxin produced by the marine diatom Pseudo-nitzschia", MAR CHEM, 76(1-2), 2001, pp. 127-134

Abstract

Toxigenic species of the pennate diatom Pseudo-nitzschia can produce domoic acid (DA), an analog of the excitatory neurotransmitter glutamate and known to cause the human illness amnesic shellfish poisoning (ASP). Although the trophic transfer of this phycotoxin resulting in mass marine bird and mammal mortality has recently been demonstrated, the physiological role of domoic acid to the causative organism is still unknown. Domoic acid is a small tricarboxylate amino acid whose structure resembles that of known iron-complexing agents produced by terrestrial plants, such as mugineic acid. Thissimilarity in chemical structure of domoic acid to other phytosiderophoressuggests a role for domoic acid as a trace metal chelator. Using a highly sensitive adsorptive cathodic stripping voltammetric technique, we investigated the iron and copper-binding characteristics of domoic acid revealing it does form chelates with both iron and copper and with the following conditional stability constants: K-FeDA,Fe(III)'(cond) = 10(8.7 +/- 0.5) M-1 andK-CuDA,Cu(II)'(cond) = 10(9.0 +/- 0/2) M-1 (K-FeDA,Fe3+(cond) = 10(18.7 +/- 0.5) M-1 and K-CuDA, Cu2+(cond) = 10(10.3) +/- M-1). Certain Pseudo-nitzschia species may therefore produce domoic acid selectively bind trace metals in order to either increase the availability of an essential micronutrient, such as in the case of iron, or to decrease the availability of a potentially toxic trace metal, such as in the case of copper. The strength with which domoic acid binds iron and copper in seawater combined with concentrations of dissolved domoic acid potentially produced and released during toxic bloom conditions render dissolved iron and copper sufficiently bound to domoic acid in seawater so as to affect their chemical speciation and thus their biological availability. In addition, domoic acid may be particularly important in solubilizing particulate iron suspended in these coastal waters where Pseudo-nitzschia blooms tend to occur. Thus, possible physiologicalroles for domoic acid with respect to the harmful algal species Pseudo-nitzschia may include the acquisition (iron) or detoxification (copper) of trace metals in seawater. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/11/20 alle ore 04:12:08