Explanation of the non-hyperbolic kinetics of the glutathione S-transferases by the simplest steady-state random sequential Bi Bi mechanism.
We have demonstrated that the simplest steady-state random sequential Bi Bi mechanism is sufficient to explain the previously reported non-hyperbolic kinetics of glutathione S-transferase 3-3 [Pabst MJ et al., J Biol Chem 249: 7140-7150, 1974; Jakobson I et al., Biochem J 177: 861-868, 1979]. The metabolism of 1-chloro-2,4-dinitrobenzene by rat liver glutathione S-transferase isoenzymes 2-2 and 3-3 and of 1,2-dichloro-4-nitrobenzene by isoenzyme 3-4 was shown to exhibit non-hyperbolic kinetics, which are best fit by the simplest steady-state random sequential Bi Bi mechanism. Neither more complex steady-state mechanisms nor the superimposition of product inhibition or enzyme memory on the simplest steady-state mechanism was necessary to generate non-hyperbolic kinetics for the glutathione S-transferases.
Ivanetich
K M
KM
Biomolecular Resource Center, University of California Medical School, San Francisco 94143-0541.
Goold
R D
RD
Sikakana
C N
CN
D000818:Animals; D004137:Dinitrochlorobenzene / Q000494:pharmacology; D005982:Glutathione Transferase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D009578:Nitrobenzenes / Q000494:pharmacology; D051381:Rats
D004137:Dinitrochlorobenzene; D007527:Isoenzymes; D009578:Nitrobenzenes; C028328:1,2-dichloro-4-nitrobenzene; D005982:Glutathione Transferase