Susceptibility of human DGAT2 activity to cysteine-specific modifying reagents.

(A) Membrane extracts from human DGAT2-overexpressing Sf9 insect cells were treated with indicated concentrations of NEM or IA. Human DGAT2 activity was measured by using the conventional extraction-based in vitro DGAT assay. The relative DGAT2 activity in percentage was calculated by setting the value from DMSO-treated sample to 100%. (B) Selective inhibitory effect of NEM on human DGAT2 activity compared to that on human DGAT1 and GPAT1. Membrane extracts from human DGAT2-, DGAT1-, or GPAT1-overexpressing Sf9 insect cells were treated with indicated concentrations of NEM or DMSO. Human DGAT1, DGAT2, and GPAT1 activity was measured by using the conventional extraction-based in vitro assays which are described in detail in the Materials and Methods section. The relative enzyme activity in percentage was calculated by setting the value from DMSO-treated sample to 100%. The mean values and standard deviations were determined from four independent assays.