title: Detection of free and covalently bound microcystins in animal tissues by liquid chromatography-tandem mass spectrometry.
abstract: Microcystins are cyanobacterial hepatotoxins capable of accumulation into animal tissues. The toxins act by inhibiting specific protein phosphatases and both non-covalent and covalent interactions occur. The 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) method determines the total, i.e. the sum of free and protein-bound microcystin in tissues. The aim of the method development in this paper was to tackle the problems with the MMPB methodology: the rather laborious workflow and the loss of material during different steps of the method. In the optimised workflow the oxidation recovery was of acceptable level (29-40%), the extraction efficiency good (62-97%), but the signal suppression effect from the matrix remained severe in our system (16-37% signal left). The extraction efficiency for the determination of the free, extractable microcystins, was found to be good, 52-100%, depending on the sample and the toxin variant and concentration.
authors.affiliation: Department of Biochemistry and Pharmacy, Abo Akademi University, Tykistökatu 6 A, Biocity 3rd floor, FI-20520, Turku, Finland. mneffling@gmail.com
authors.forename: Milla-Riina
authors.initials: MR
authors.lastname: Neffling
authors.forename: Emilie
authors.initials: E
authors.lastname: Lance
authors.forename: Jussi
authors.initials: J
authors.lastname: Meriluoto
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods*; D000458:Cyanobacteria / Q000378:metabolism; D052998:Microcystins / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D011485:Protein Binding; D012908:Snails / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D001427:Bacterial Toxins; D052998:Microcystins; C078588:microcystin