Effects of post translational modifications on the periplasmic loop of MscL determined by in vivo channel activity.

The viability of the osmotically fragile strain MJF455 expressing MscL cysteine substituted mutants from residues L47 to H74 (insert), was measured after an osmotic down-shock. The graphs show the differences in viability between non-treated and post-transnationally modified channels with (A) the hydrophobic MTS reagents MTSBn (blue), decyl-MTS (red) or 4HB-MTS (green) or (B) the negatively charged MTSES- (blue) and positively charged MTSET+ (red). The red grid line indicates a ± 50% change that was used as a threshold for further studies.