Figure 8. Recovery effects of TCEP and DTT on the enzymatic methylation of iAs³⁺.

(A) HPLC-ICP-MS spectra of arsenic species on hAS3MT. Control: hAS3MT (2.0 µM) catalyzed the iAs³⁺ methylation in the GSH reaction system for 60 min and dialysis against PBS. Dialysis-PBS, Dialysis-DTT (0.5 mM), and Dialysis-TCEP (0.7 mM): PBS, DTT, or TCEP separately incubated with the dialyzed hAS3MT in the presence of AdoMet (0.1 mM) at 37°C for another 60 min. (B) CD spectra and (C) corresponding secondary structure of hAS3MT. Enzyme: hAS3MT (2.0 µM) in PBS. Error bars represent S.D. from the mean of three independent experiments.