title: Detection of 13,19-didesmethyl C spirolide by fluorescence polarization using Torpedo electrocyte membranes.
abstract: Fluorescence polarization (FP) is a powerful tool for studying molecular interactions by monitoring changes in the apparent size of fluorescent molecules. In this paper, a previously described fluorescence polarization assay was used to detect 13,19-didesmethyl C spirolide. The assay is based on the competition of cyclic imine marine biotoxins with alpha-bungarotoxin for binding to nicotinic acetylcholine receptor-enriched membranes of Torpedo marmorata. The 13,19-didesmethyl C spirolide was detected in buffer and mussel matrix. The sensitivity of the assay for the 13,19-didesmethyl C spirolide and the 13-desmethyl C spirolide was similar. After an acetone/chloroform extraction of spiked mussel meat, the average recovery rate of 13,19-didesmethyl C spirolide was 77.7 +/- 1.9%. The quantification range for this toxin in mussel was 40-200 microg/kg of shellfish meat. This assay can be used to detect the spirolides 13,19-didesmethyl C spirolide and 13-desmethyl C spirolide, in shellfish as a screening assay.
authors.affiliation: Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, 27002 Lugo, Spain.
authors.forename: Eva S
authors.initials: ES
authors.lastname: Fonfría
authors.forename: Natalia
authors.initials: N
authors.lastname: Vilariño
authors.forename: Jordi
authors.initials: J
authors.lastname: Molgó
authors.forename: Rómulo
authors.initials: R
authors.lastname: Aráoz
authors.forename: Paz
authors.initials: P
authors.lastname: Otero
authors.forename: Begoña
authors.initials: B
authors.lastname: Espiña
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Louzao
authors.forename: Mercedes
authors.initials: M
authors.lastname: Alvarez
authors.forename: Luis M
authors.initials: LM
authors.lastname: Botana
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002038:Bungarotoxins / Q000378:metabolism; D005454:Fluorescence Polarization / Q000379:methods; D008387:Marine Toxins / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000737:chemistry*; D011978:Receptors, Nicotinic / Q000378:metabolism; D012680:Sensitivity and Specificity; D013141:Spiro Compounds / Q000032:analysis* / Q000378:metabolism; D014101:Torpedo / Q000378:metabolism
chemical_list: C544516:13,19-didesmethyl spirolide C; C517170:13-desmethylspirolide C; D002038:Bungarotoxins; D008387:Marine Toxins; D011978:Receptors, Nicotinic; D013141:Spiro Compounds