Complexation of okadaic acid : A preliminary study

Norte, Manuel; Fernández, JoséJ.; Souto, Marı́a L.; Gavín, José A.; Candenas, Luz; Ausina, Pilar

doi:10.1016/s0960-894x(98)00152-8

Cited by 6 publications

(12 citation statements)

References 5 publications

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“…In addition, signals from H-7, H-12, H-14, H-15, H-23 and Me-41 clearly changed their chemical shifts upon addition of EDTA (Figure 1). Following this opening observation, a series of experiments were carried out in order to identify the ion included in this complex [20]. The experiments consisted of the treatment of OA samples with different metal ions such as Li + , Na + , K + , Ca 2+ and Mg 2+ .…”

Section: Dimerization Of Okadaic Acid Overviewmentioning

confidence: 99%

Self-Association of Okadaic Acid: Structural and Pharmacological Significance

et al. 2013

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Okadaic acid (OA) has been an invaluable pharmacological tool in the study of cellular signaling. The great affinity of this polyether for its targets together with its high specificity to inhibit certain protein phosphatases enables the differential study of these proteins. Crystallographic structures of protein phosphatases in complex with OA show a 1:1 protein to toxin ratio. Nevertheless, it has been found that OA is able to self-associate under certain conditions although very little is known about the importance of this phenomenon. Here we review the available knowledge on the latter topic and we report on the existence of an unusual self-associated tetrameric form. The structure of these oligomers is proposed based on spectroscopic data and molecular modeling calculations.

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Section: Dimerization Of Okadaic Acid Overviewmentioning

confidence: 99%

Self-Association of Okadaic Acid: Structural and Pharmacological Significance

et al. 2013

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“…For example, pahayokolide A, one of the recently isolated compounds, and brevetoxin (PbTx-2 used in this study) were studied for the first time for their complexation with metals. Although microcytins have been studied by a few research groups (Humble et al 1997;Yan et al 2000;Saito et al 2008;Norte et al 1998), complexation of microcystin-YR with metal ions has never been previously studied. In addition to metal ions, metalloid, such as anion HAsO 4 2-was also included in the current study.…”

Section: Discussionmentioning

confidence: 99%

“…The microcystin-metal complexes were observed as both singly charged and doubly charged ion peaks (Saito et al 2008). Norte et al (1998) carried out a study on complexation between okadaic acid and univalent and divalent metal ions utilizing nuclear magnetic resonance (NMR). A summary of previous studies on the complexation of metals and toxins is shown in Table 1.…”

Section: The Complexation Of Algal Toxins With Metalsmentioning

confidence: 99%

“…Because of the complexation of algal toxin with metal cation, the redox potential of the metal cation would become higher than that of the free species. Nuclear magnetic resonance (NMR) (Saito et al 2008) and mass spectrometry (MS) (Norte et al 1998) were also employed to qualitatively study the complexation of the algal toxin with the metal cation in the previous studies. In the current work, the traditional equilibrium dialysis was used to determine the differences of the metal ion concentration in both the inside and the outside solutions.…”

Section: Comparison With Previous Studiesmentioning

confidence: 99%

“…Besides the above limited study, only a few other papers discussed these algal toxin-metal ion complexes that could be potentially formed in the coexistence of metals and algal toxins (Humble et al 1997;Norte et al 1998;Yan et al 2000;Rue and Bruland 2001;Saito et al 2008). …”

Section: Introductionmentioning

confidence: 99%

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Interactions of Toxic Metals with Algal Toxins Derived from Harmful Algal Blooms

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The purposes of this study were to characterize the complexation of toxic metals with algal toxins and to determine the effects of arsenic and copper on the growth of Karenia brevis under specific experimental conditions. Microcystins, pahayokolides, brevetoxins and okadaic acid were used as representatives of algal toxins while arsenic, copper, cadmium, cobalt, iron, manganese and mercury were selected as typical toxic metals (including metalloids here) in the aquatic environment. The stabilities of the toxin-metal complexes were determined using equilibrium dialysis and/or centrifugal ultrafiltration technique. A direct exposure of arsenic and copper to the K. brevis was carried out to determine the effects of these metals to the growth of the algal cell.

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Self-Association of Okadaic Acid upon Complexation with Potassium Ion

et al. 2003

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Okadaic acid (OA) is a toxin responsible for diarrhetic shellfish poisoning and is an extremely useful tool for studying processes that are regulated by phosphorylation, although the exact mechanism of action is still undetermined. We report on a study that proved the existence of OA in an unusual dimeric form when complexed with potassium ion. The proposed structure of this dimer is based on spectroscopic and conformational studies.

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Complexation of okadaic acid : A preliminary study

Cited by 6 publications

References 5 publications

Self-Association of Okadaic Acid: Structural and Pharmacological Significance

Self-Association of Okadaic Acid: Structural and Pharmacological Significance

Interactions of Toxic Metals with Algal Toxins Derived from Harmful Algal Blooms

Self-Association of Okadaic Acid upon Complexation with Potassium Ion

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