Purification, characterization and kinetic properties of the Taenia solium glutathione S-transferase isoform 26.5 kDa

• Published in: Parasitology research (1987) Vol. 93; no. 2; pp. 137 - 144
• Main Authors: Plancarte, A, Rendon, J L, Landa, A
• Format: Journal Article
• Language: English
• Published: Germany 01.06.2004
• Subjects: Animals; Glutathione Transferase - chemistry; Glutathione Transferase - isolation & purification; Glutathione Transferase - metabolism; Hydrogen-Ion Concentration; Isoenzymes - chemistry; Isoenzymes - isolation & purification; Isoenzymes - metabolism; Kinetics; Taenia - enzymology; Taenia - growth & development; Temperature
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-004-1103-y

Glutathione S-transferases are major phase II detoxification enzymes. Taenia solium, a parasite of humans and pigs, is exposed to toxic products. The aim of this work was to purify and characterize a T. solium glutathione S-transferase isoform of 26.5 kDa (SGST26.5) in order to obtain its kinetic parameters. Homogeneous SGST26.5 was obtained by a simple purification procedure. SGST26.5 showed a p I of 7.07, and a native Mr of 60 kDa with 26.5 kDa subunits. The optimum activity for SGST26.5 was found at pH 6.5-7.0 in the range 10-42 degrees C. SGST26.5 had a specific enzyme activity of 78, 7.1, 6.6, and 0.7 microM min(-1) mg(-1) with CDNB, 1,2-dichloro-4-nitrobenzene, 2,4-hexadienal and trans-2-nonenal as substrates, respectively. It also had a kcat/ K(mCDNB)=2.15 x 10(3) M(-1 )s(-1), kcat/ KmGSH)=4.5 x 10(3) M(-1 )s(-1) and Vmax for GSH and CDNB=74 and 77 microM min(-1) mg(-1), respectively. SGST26.5 was inhibited in a noncompetitive form by cibacron blue, bromosulfophthalein and triphenyltin chloride. Inhibition studies as a function of inhibitor concentration show that the enzyme is a homodimer. Bireactant system analysis show that it follows an ordered sequential mechanism.