Purification and characterization of glutathione transferases from the sea bass (Dicentrarchus labrax) liver.
Two forms of glutathione transferase were purified from liver cytosol of the sea bass (Dicentrarchus labrax) by GSH-Sepharose affinity chromatography followed by chromatofocusing. The major enzyme (DL-GST-6.7; 75% of total activity bound to the column) has a pI value of 6.7 and is composed of two subunits of apparent molecular mass 26.5 kDa. The minor enzyme (DL-GST-8.2; 25% of total activity bound to the column) has a pI value of 8.2 and is composed of two subunits of molecular mass 23.5 kDa. Both isoenzymes appear to have blocked N-terminal. The purified proteins were characterized with respect to substrate specificity, CD spectra, TNS binding properties (with 2-toluidinylnaphthalene 6-sulfonate), and immunological reactivity. Partial internal amino acid sequence was also determined for each isoenzyme. The results obtained suggest that DL-GST-6.7 and DL-GST8.2 are novel GSTs belonging, respectively, to theta and alpha classes.
Angelucci
S
S
Dipartimento di Scienze Biomediche, Università "G. D'Annunzio,", Chieti, 66100, Italy.
Sacchetta
P
P
Moio
P
P
Melino
S
S
Petruzzelli
R
R
Gervasi
P
P
Di Ilio
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000737:chemistry* / Q000145:classification; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000737:chemistry; D008099:Liver / Q000201:enzymology*; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D009282:Naphthalenesulfonates / Q000378:metabolism; D011485:Protein Binding; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D007527:Isoenzymes; D009282:Naphthalenesulfonates; C009497:2-(4-toluidino)-6-naphthalenesulfonic acid; D005982:Glutathione Transferase