title: Surface plasmon resonance biosensor method for palytoxin detection based on Na+,K+-ATPase affinity.
abstract: Palytoxin (PLTX), produced by dinoflagellates from the genus Ostreopsis was first discovered, isolated, and purified from zoanthids belonging to the genus Palythoa. The detection of this toxin in contaminated shellfish is essential for human health preservation. A broad range of studies indicate that mammalian Na+,K+-ATPase is a high affinity cellular receptor for PLTX. The toxin converts the pump into an open channel that stimulates sodium influx and potassium efflux. In this work we develop a detection method for PLTX based on its binding to the Na+,K+-ATPase. The method was developed by using the phenomenon of surface plasmon resonance (SPR) to monitor biomolecular reactions. This technique does not require any labeling of components. The interaction of PLTX over immobilized Na+,K+-ATPase is quantified by injecting different concentrations of toxin in the biosensor and checking the binding rate constant (Kobs). From the representation of Kobs versus PLTX concentration, the kinetic equilibrium dissociation constant (K(D)) for the PLTX-Na+,K+-ATPase association can be calculated. The value of this constant is K(D) = 6.38 × 10-7 ± 6.67 × 10-8 M PLTX. In this way the PLTX-Na+,K+-ATPase association was used as a suitable method for determination of the toxin concentration in a sample. This method represents a new and useful approach to easily detect the presence of PLTX-like compounds in marine products using the mechanism of action of these toxins and in this way reduce the use of other more expensive and animal based methods.
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. andrea.fernandez.araujo@rai.usc.es.
authors.forename: Amparo
authors.initials: A
authors.lastname: Alfonso
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. m.pazos@usc.es.
authors.forename: María-José
authors.initials: MJ
authors.lastname: Pazos
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. andrea.fernandez.araujo@rai.usc.es.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fernández-Araujo
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. araceli.tobio@rai.usc.es.
authors.forename: Araceli
authors.initials: A
authors.lastname: Tobio
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. mcalfonso@cifga.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Alfonso
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. mmercedes.rodriguez@usc.es.
authors.forename: Mercedes R
authors.initials: MR
authors.lastname: Vieytes
authors.affiliation: Department of Pharmacology, Veterinary School, University of Santiago de Compostela, 27002 Lugo, Spain. luis.botana@usc.es.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Botana
mesh_terms: D000178:Acrylamides / Q000032:analysis*; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D003064:Cnidarian Venoms; D004141:Dinoflagellida / Q000378:metabolism; D004285:Dogs; D007668:Kidney / Q000378:metabolism; D008387:Marine Toxins / Q000032:analysis; D023421:Models, Animal; D012758:Shellfish / Q000032:analysis; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D020349:Surface Plasmon Resonance / Q000379:methods*; D000095702:Polyether Toxins
chemical_list: D000178:Acrylamides; D003064:Cnidarian Venoms; D008387:Marine Toxins; D000254:Sodium-Potassium-Exchanging ATPase; C010272:palytoxin; D000095702:Polyether Toxins