title: Analysis of interactions of brevetoxin-B and human serum albumin by liquid chromatography/mass spectrometry.
abstract: Brevetoxins are neurotoxins produced by marine dinoflagellates, primarily Karenia brevis, and can cause intoxication and even mortality of marine species, affect human health through the consumption of brevetoxin-contaminated shellfish, and effect respiratory irritation through aerosol exposure at coastal areas. Brevetoxin-A and brevetoxin-B, the major brevetoxins produced in algae, are metabolized to a series of amino acid and peptide-related derivatives in shellfish through the reactions of the amino acid residue cysteine with an α,β-unsaturated aldehyde group. In this paper, covalent interactions between brevetoxin and proteins were investigated using brevetoxin-B and human serum albumin (HSA) as a model. It is demonstrated that both noncovalent and covalent interactions can occur between brevetoxin-B and HSA with in vitro experiments. Covalent adducts of brevetoxin-B and HSA were generated under physiological conditions and reduced with sodium borohydride based on the reaction conditions of single amino acid residues with brevetoxin-B. LC/MS analysis of toxin-treated HSA recognized the formation of the intact protein adducts with primarily one and two toxin molecules attached to one HSA molecule. HSA treated with/without brevetoxin-B was digested with trypsin, trypsin following chymotrypsin, and Pronase, respectively, for LC/MS analysis of adduction sites. Brevetoxin-B was found to react primarily with Cys(34) and His(3) and with His and Lys at other sites of HSA with variable reactivity and with Lys in general the least reactive.
authors.affiliation: Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, NOAA/National Ocean Service, 219 Fort Johnson Road, Charleston, South Carolina 29412, USA.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Wang
authors.forename: John S
authors.initials: JS
authors.lastname: Ramsdell
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry; D004141:Dinoflagellida / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D006801:Humans; D008387:Marine Toxins / Q000737:chemistry* / Q000633:toxicity; D013058:Mass Spectrometry; D035964:Oxocins / Q000737:chemistry* / Q000633:toxicity; D011402:Pronase / Q000378:metabolism; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism; D000095702:Polyether Toxins
chemical_list: D002918:Chymotrypsin; D003545:Cysteine; D006639:Histidine; D008387:Marine Toxins; D035964:Oxocins; D011402:Pronase; D012709:Serum Albumin; D014357:Trypsin; C043466:brevetoxin B; D000095702:Polyether Toxins