Isolation, characterization, and quantitative analysis of Microviridin J, a new Microcystis metabolite toxic to Daphnia.
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.
Rohrlack
Thomas
T
Freshwater Biological Laboratory, University of Copenhagen, Helsingørsgade 51, 3400 Hillerød, Denmark. trohrlack@zi.ku.dk
Christoffersen
Kirsten
K
Hansen
Poul Erik
PE
Zhang
Wei
W
Czarnecki
Olaf
O
Henning
Manfred
M
Fastner
Jutta
J
Erhard
Marcel
M
Neilan
Brett A
BA
Kaebernick
Melanie
M
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
D001427:Bacterial Toxins; D010456:Peptides, Cyclic; C480589:microviridin J