Akademik Veri Yönetim Sistemi
Biochemical Medicine and Metabolic Biology, cilt.44, sa.2, ss.142-150, 1990 (SCI-Expanded)
Cytosolic glutathione S-transferases were purified from human jejunal mucosa by affinity chromatography on S-hexylglutathione-Sepharose 4B. Chromatofocusing in the pH range 7-4 yielded peaks with apparent pI's of 7.2 (peak 1), 5.2 (peak 2), and 4.4 (peak 3). Each enzymatic fraction was shown to have a homodimeric structure, with subunit mass of 24.9 ± 0.5 (P1), 27.9 ± 0.9 (P2), and 23.4 ± 0.8 (P3) kDa, as determined by SDS-PAGE. The substrate specificity of each peak was tested using discriminating substrates for basic, near-neutral, and acidic GSTs. With cumene hydroperoxide, the diagnostic substrate for the α (basic) class of GSTs, P1 showed 8- to 36-fold higher activity than P2 and P3. Ethacrynic acid, the selective substrate for the acidic enzyme (π), gave highest activity with P3. The inhibitory potentials of sulfobromophthalein, cibacron blue, tributyltin acetate, triphenyltin chloride, and bromphenol blue were also tested. A qualitative resemblance between P1 and α, and P3 and π GSTs was noted. The substrate specificity and inhibition parameters of P2 corresponded most closely to those of μ-GST. The relative abundances of P1, P2, and P3 (based on CDNB-conjugating activity) were 35, 5, and 60%, respectively. © 1990.