The pKa values of the thiol groups of DTE are 9.0 and 9.9, which is higher than the corresponding values for DTT (9.3 and 9.5). Since reduction of disulfide bonds requires thiolate (ionized thiol), DTE is less efficient at lower pH compared to DTT.
The pKa values for the thiol groups in DTE are higher than those of DTT (pKa 9.3 and 9.5), indicating that reducing disulfide bonds requires a thiolate ion, making DTE less effective at lower pH levels compared to DTT.