%0 Journal Article
%T Effects of the Amino Acid Constituents of Microcystin Variants on Cytotoxicity to Primary Cultured Rat Hepatocytes
%A Kumiko Shimizu
%A Tomoharu Sano
%A Reiji Kubota
%A Norihiro Kobayashi
%A Maiko Tahara
%A Tomoko Obama
%A Naoki Sugimoto
%A Tetsuji Nishimura
%A Yoshiaki Ikarashi
%J Toxins
%D 2014
%I MDPI AG
%R 10.3390/toxins6010168
%X Microcystins, which are cyclic heptapeptides produced by some cyanobacterial species from algal blooms, strongly inhibit serine/threonine protein phosphatase and are known as hepatotoxins. Microcystins have many structural variations, yet insufficient information is available on the differences in the cytotoxic potentials among the structural variants. In this study, the cytotoxicities of 16 microcystin variants at concentrations of 0.03¨C10 ¦Ìg/mL to primary cultured rat hepatocytes were determined by measuring cellular ATP content, and subsequently determined by their 50% inhibitory concentration (IC 50). Differences in the amino acid constituents were associated with differences in cytotoxic potential. [d-Asp 3, Z-Dhb 7] microcystin-LR exhibited the strongest cytotoxicity at IC 50 of 0.053 ¦Ìg/mL among the microcystin variants tested. Furthermore, [d-Asp 3, Z-Dhb 7] microcystin-HtyR was also highly cytotoxic. These results suggest that both d-Asp and Z-Dhb residues are important in determining the cytotoxic potential of microcystin variants.
%K microcystin
%K variants
%K cytotoxicity
%K primary cultured rat hepatocytes
%K environmental water
%U http://www.mdpi.com/2072-6651/6/1/168