Affinity of one GSH bound per Microsomal glutathione transferase 1 trimer

Value 16 µM Range: ±4 µM
Organism Rat Rattus norvegicus
Reference Alander et al., Microsomal glutathione transferase 1 exhibits one-third-of-the-sites-reactivity towards glutathione. Arch Biochem Biophys. 2009 Jul 1 487(1):42-8. p. 44 right column, 2nd paragraphPubMed ID19416719
Method In order to re-evaluate their previous binding data researchers repeated equilibrium dialysis experiments with 35S-labelled GSH as described in [Sun et al., 1997 PMID 9337868], with the exception that 10 mM b-mercaptoethanol was used as a reducing agent instead of 0.1 M DTT. With the enzyme concentration used (29–31µM trimer corresponding to ˜90µM potential binding sites), they could only observe one GSH bound per trimer (Bmax 0.85±0.03, Kd 16±4µM, Eq. (1) and Fig. 2), confirming their previous results [Sun et al., above].
Comments Researchers therefore suggest that MGST1 harbours one high affinity and two low affinity sites for GSH. MGST1 binds three GSH molecules per trimer. See BNID 105544, 105546, 105547
Entered by Uri M
ID 105545