the purification procedure involved deae-cellulose chromatography , ( nh4 ) 2so4 precipitation , affinity chromatography on sepharose 4b to which glutathione was coupled and cm-cellulose chromatography , and allowed the isolation of glutathione s-transferases x , a , b and c in relatively large quantities suitable for the investigation of the toxicological role of these enzymes .
C0184661
procedure
C0220825
investigation