Characterization of hepatic and extrahepatic glutathione S-transferases inrainbow trout (Oncorhynchus mykiss) and their induction by 3,3 ',4,4 '-tetrachlorobiphenyl
M. Perez-lopez et al., Characterization of hepatic and extrahepatic glutathione S-transferases inrainbow trout (Oncorhynchus mykiss) and their induction by 3,3 ',4,4 '-tetrachlorobiphenyl, FISH PHYS B, 22(1), 2000, pp. 21-32
Liver, kidney, gill and olfactory epithelium cytosolic fractions of rainbow
trout (Oncorhynchus mykiss) were examined for glutathione S-transferase (G
ST) contents. Proteins retained on a glutathione (GSH)-affinity matrix were
separated as monomers by reversed-phase HPLC and characterized by immunobl
otting, mass spectrometry and partial amino acid sequence. For each organ c
oncerned, a specific pattern of these proteins was determined and appeared
similar for liver and kidney on one hand, and for gill and olfactory epithe
lium on the other hand. It was confirmed that the prominent hepatic GST is
a class pi enzyme, also constitutively expressed as a major isoform in the
four organs studied. Moreover, a class pi variant and two new class mu GST
subunits were characterized in minor fractions. An unknown protein, which w
as found major in gills and olfactory epithelium, exhibited some characteri
stics of class theta GSTs. Occurrence of possible GSH-adduct formation obse
rved on two distinct monomers in specific experimental conditions is discus
sed. These results and methods were used to investigate the effect of 3,3',
4,4'-tetrachlorobiphenyl (TCB), a polychlorinated biphenyl (PCB), on GST ex
pression in trout liver. From HPLC-profiling, significant co-induction of t
he major class pi and the two minor class mu GST subunits was observed in t
rout after waterborne exposure to TCB which was followed by a slight increa
se in 1-chloro-2,4-dinitrobenzene (CDNB) activity. The present work allows
qualitative evaluation of the specific detoxification potential of rainbow
trout. The use of HPLC-profiling of GSTs as a possible tool for the biomoni
toring of polluted aquatic environment is suggested.