title: Isolation, characterization, and quantitative analysis of Microviridin J, a new Microcystis metabolite toxic to Daphnia.
abstract: This paper describes the purification and characterization of microviridin J. a newly discovered metabolite of Microcystis that causes a lethal molting disruption in Daphnia spp., upon ingestion of living cyanobacterial cells. Microviridin J consists of an acetylated chain of 13 amino acids arranged in three rings and two side chains. Unlike other known isoforms of microviridin, microviridin J contains arginine that imparts a unique solution conformation characterized by proximal hydrophobic interactions between Arg and other regions of the molecule. This eventually results in the formation and stabilization of an additional ring system. Microviridin J potently inhibits porcine trypsin, bovine chymotrypsin, and daphnid trypsin-like proteases. The activity against trypsin is most likely due to Arg and its distinctive conformational interactions. Overall, the data presented for microviridin J emphasize once again the ability of cyanobacteria to produce numerous and potent environmental toxins.
authors.affiliation: Freshwater Biological Laboratory, University of Copenhagen, Helsingørsgade 51, 3400 Hillerød, Denmark. trohrlack@zi.ku.dk
authors.forename: Thomas
authors.initials: T
authors.lastname: Rohrlack
authors.forename: Kirsten
authors.initials: K
authors.lastname: Christoffersen
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Hansen
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Olaf
authors.initials: O
authors.lastname: Czarnecki
authors.forename: Manfred
authors.initials: M
authors.lastname: Henning
authors.forename: Jutta
authors.initials: J
authors.lastname: Fastner
authors.forename: Marcel
authors.initials: M
authors.lastname: Erhard
authors.forename: Brett A
authors.initials: BA
authors.lastname: Neilan
authors.forename: Melanie
authors.initials: M
authors.lastname: Kaebernick
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D003621:Daphnia; D009682:Magnetic Resonance Spectroscopy; D046931:Microcystis / Q000737:chemistry / Q000472:pathogenicity*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D001427:Bacterial Toxins; D010456:Peptides, Cyclic; C480589:microviridin J