Comparative study on in vitro inhibition of grass carp (Ctenopharyngodon idellus) and mouse protein phosphatases by microcystins

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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  • L. Xu
  • P. K S Lam
  • J. Chen
  • Y. Zhang
  • K. Harada


Original languageEnglish
Pages (from-to)71-75
Journal / PublicationEnvironmental Toxicology
Issue number2
Publication statusPublished - 2000


Microcystins isolated from toxic cyanobacteria are potent inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A). The inhibitory effects of three structural variants of microcystins (microcystin-LR, -YR, and -RR) on protein phosphatases isolated and purified from the liver and kidney of grass carp (Ctenopharyngodon idellus) were investigated using the 32P radiometric assay. The relationships between percentage inhibition of protein phosphatase activity and microcystin levels followed a typical dose-dependent sigmoid curve. These results were compared to those obtained from mouse PP2A. The degree and pattern of inhibition of both fish and mouse protein phosphatases by microcystins were similar. Protein phosphatases in crude fish tissue homogenates showed similar inhibition patterns as purified fish PP2A toward microcystins. (C) 2000 by John Wiley and Sons, Inc.

Research Area(s)

  • Fish protein phosphatases, In vitro inhibition, Microcystins

Citation Format(s)