has role xenobiotic EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor microcystin microcystin-LR CHEBI:6925 A microcystin consisting of <small>D</small>-alanyl, <small>L</small>-leucyl, (3<i>S</i>)-3-methyl-<small>D</small>-β-aspartyl,<small>L</small>-arginyl, 2<i>S</i>,3<i>S</i>,4<i>E</i>,6<i>E</i>,8<i>S</i>,9<i>S</i>)-3-amino-4,5,6,7-tetradehydro-9-methoxy-2,6,8-trimethyl-10-phenyldecanoyl, <small>D</small>-γ-glutamyl, and 2,3-didehydro-<em>N</em>-methylalanyl residues joined into a 25-membered macrocycle. Produced by the cyanobacterium <em>Microcystis aeruginosa</em>, it is the most studied of the microcystins. environmental contaminant