title: Antibody characterization and immunoassays for palytoxin using an SPR biosensor.
abstract: Palytoxin (PLTX), a polyether marine toxin originally isolated from the zoanthid Palythoa toxica, is one of the most toxic non-protein substances known. Fatal poisonings have been linked to ingestion of PLTX-contaminated seafood, and effects in humans have been associated with dermal and inhalational exposure to PLTX containing organisms and waters. Additionally, PLTX co-occurrence with other well-characterized seafood toxins (e.g., ciguatoxins, saxitoxins, tetrodotoxin) has hindered direct associations of PLTX to seafood-borne illnesses. There are currently no validated methods for the quantitative detection of PLTX(s). As such, a well-characterized, robust, specific analytical technique is needed for the detection of PLTX(s) in source organisms, surrounding waters, and clinical samples. Surface plasmon resonance (SPR) biosensors are ideally suited for antibody characterization and quantitative immunoassay detection. Herein, we describe a newly developed SPR assay for PLTX. An anti-mouse substrate was used to characterize the kinetic values for a previously developed monoclonal anti-PLTX. The characterized antibody was then incorporated into a sensitive, rapid, and selective PLTX assay. Buffer type, flow rate, analyte-binding time, and regeneration conditions were optimized for the antibody-PLTX system. Cross-reactivity to potentially co-occurring seafood toxins was also evaluated. We show that this optimized assay is capable of measuring low- to sub-ng/mL PLTX levels in buffer and two seafood matrices (grouper and clam). Preliminary results indicate that this SPR biosensor assay allows for (1) rapid characterization of antibodies and (2) rapid, sensitive PLTX concentration determination in seafood matrices. Method development information contained herein may be broadly applied to future PLTX detection and/or antibody characterization efforts.
authors.affiliation: Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740, USA. betsy.yakes@fda.hhs.gov
authors.forename: Betsy Jean
authors.initials: BJ
authors.lastname: Yakes
authors.forename: Stacey L
authors.initials: SL
authors.lastname: DeGrasse
authors.forename: Mark
authors.initials: M
authors.lastname: Poli
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Deeds
mesh_terms: D000178:Acrylamides / Q000032:analysis* / Q000276:immunology; D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D003064:Cnidarian Venoms; D007118:Immunoassay / Q000379:methods*; D008387:Marine Toxins / Q000032:analysis* / Q000276:immunology; D051379:Mice; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*; D000095702:Polyether Toxins
chemical_list: D000178:Acrylamides; D000911:Antibodies, Monoclonal; D003064:Cnidarian Venoms; D008387:Marine Toxins; C010272:palytoxin; D000095702:Polyether Toxins