Figure 2. Reactivation of FIGDH by incubation with different thiols.

FIGDH (4.4 µg pure protein in 400 µl) was incubated at 37°C with different thiols (•, no thiol; ○, 2-mercaptoethanol; ▾, DTT; Δ, cysteine; ▪, GSH; □, thioglycolate; ♦, methyl thioglycolate and ◊, cysteamine) and 20 µl aliquots were withdrawn to monitor forward activity by the standard assay. The concentration of each thiol was 20 mM except in case of DTT (10 mM; to maintain equivalence of -SH groups).