[ADMAdda5]-microcystins in Planktothrix agardhii strain PH-123 (cyanobacteria)--importance for monitoring of microcystins in the environment.
Two major and two minor microcystins (MCYST) were isolated from a hepatotoxic Danish strain of Planktothrix agardhii (Gomont) Anagnostidis et Komárek by reversed-phase high-performance liquid chromatography. The microcystins were characterized by UV spectroscopy, amino acid analysis, fast atom bombardment mass spectrometry (FABMS), and high-resolution FABMS. The major microcystins were further analysed by collisionally induced tandem electrospray ionization MS. The microcystins were found to be demethylated variants of MCYST-HtyR (homotyrosine-arginine) and MCYST-LR (leucine-arginine). The two major microcystins contained an acetyl-demethyl variant (ADMAdda) of 3-amino-9-acetoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid (Adda). This is the first report of [ADMAdda5]-microcystins in Planktothrix. The two [ADMAdda5]-microcystins inhibited protein phosphatase activity but showed low cross-reactivity with antibodies of an enzyme-linked immunosorbent assay (ELISA), emphasizing the potential underestimation of the toxicity of natural blooms dominated by Planktothrix when microcystin content is quantified using only an ELISA.
Laub
Jesper
J
Department of Phycology, Botanical Institute, University of Copenhagen, Øster Farimagsgade 2D, DK-1353 Copenhagen K, Denmark.
Henriksen
Peter
P
Brittain
Scott M
SM
Wang
Jim
J
Carmichael
Wayne W
WW
Rinehart
Kenneth L
KL
Moestrup
Ojvind
O
D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry*; D004784:Environmental Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D005068:Eutrophication; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000187:drug effects / Q000494:pharmacology
D052998:Microcystins; D010456:Peptides, Cyclic; C078588:microcystin; D010749:Phosphoprotein Phosphatases