Microcystins
The most frequently occurring cyanobacterial toxin is microcystin-LR, produced by several species, but primarily by Microcystis areugenosa. The photo below is a Microcystis bloom in the St. Lucie River (in Florida) taken in 2005. Microcystin-LR (the structure below) is a cyclic heptapeptide which contains both proteinogenic and non-proteinogenic amino acids. Microcystin-LR is a hepatotoxin and an inhibitor of serine/ threonine protein phosphatases. We are working to understand the metabolism and disposition of microcystin-LR
