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.
[1] The enzyme degrades the cyclic peptide toxin microcystin into a linear peptide, which is 160 times less toxic.
[2] Other bacteria then further degrade the linear peptide.