:Microcystinase

Microcystinase is a protease that selectively degrades microcystin, an extremely potent cyanotoxin that causes marine pollution and can lead to human and animal food chain poisoning. The enzyme is naturally produced by a number of bacteria isolated in Japan and New Zealand. As of 2012, the chemical structure of this enzyme has not been scientifically determined.{{cite journal | pmid = 22326726 | doi=10.1016/j.toxicon.2012.01.001 | volume=59 | issue=5 | title=Heterologous expression and characterisation of microcystinase. | date=Apr 2012 | journal=Toxicon | pages=578–86| last1=Dziga | first1=Dariusz | last2=Wladyka | first2=Benedykt | last3=Zielińska | first3=Gabriela | last4=Meriluoto | first4=Jussi | last5=Wasylewski | first5=Marcin }}

The enzyme degrades the cyclic peptide toxin microcystin into a linear peptide, which is 160 times less toxic.{{Cite journal |doi = 10.1155/2013/596429|pmid = 23936728|pmc = 3712209|title = Degradation of [Dha7]MC-LR by a Microcystin Degrading Bacterium Isolated from Lake Rotoiti, New Zealand|journal = ISRN Microbiology|volume = 2013|pages = 1–8|year = 2013|last1 = Somdee|first1 = Theerasak|last2 = Thunders|first2 = Michelle|last3 = Ruck|first3 = John|last4 = Lys|first4 = Isabelle|last5 = Allison|first5 = Margaret|last6 = Page|first6 = Rachel|doi-access = free}} Other bacteria then further degrade the linear peptide.