UC San Diego

Mer proteins are 6 proteins MerA, MerE, MerF, MerT, MerC and MerP performing bacterial mercury detoxification system. One of transmembrane protein MerFt with two a helix was mutated two sets of vicinal cysteines: C21, C22, C71, and C72 with Serine pairs. The truncated structure MerFt, as a nonmetal binding protein and ideal transmembrane model protein to study solution NMR and solid-state NMR sample condition, was successfully expressed as a fusion protein with Ketosteroid Isomerase as an expression tag. CNBr (cyanogen bromide) chemical cleavage was performed to cleave KSI tag in different conditions. The protein was successfully purified with HPLC (High-Performance Liquid Chromatography) and FPLC (Fast protein liquid chromatography) size exclusion. The structural studies of this membrane protein were developed on solution NMR (Nuclear Magnetic Resonance) and solid-state NMR.