Glutathione S-transferase in the branchiopod<Emphasis Type="Italic"> Artemia salina</Emphasis>

The glutathione S-transferase enzyme system, which belongs in phase II of detoxification, has been studied in developmental stages of the branchiopod Artemia salina. The highest total activity and specific activity towards 1-chloro-2,4-dinitrobenzene was observed 48 h after hatching. The number of isoenzymes present in A. salina varies between three and four, depending on the developmental stage. The two major isoenzymes, with corresponding isoelectric points of 8.5 and 7.2, were present in all developmental stages, but at a varying rate: as the organism grew older, the alkaline isoenzyme was expressed at a higher rate. The kinetic and molecular characteristics of the enzyme were similar to those of other aquatic organisms. With regards to the kinetic characteristics, significant differences were observed between the two major isoenzymes, and, since the rate of their expression changes as the organism grows, the detoxification potential of the organism varies according to developmental stage.Communicated by O. Kinne, Oldendorf/Luhe