Structure, Function and Dynamics of mCoral, a pH-Responsive Engineered Variant of the mCherry Fluorescent Protein with Improved Hydrogen Peroxide Tolerance.

ABSTRACT: The red fluorescent protein mCherry is one of the most widely used fluorescent proteins in biology. Here, we have changed the chromophore chemistry by converting the thioether group of M66 to a thiol group through mutation to cysteine. The new variant, termed mCoral (due to its orange fluorescence hue), has similar brightness to mCherry but improved resistance to hydrogen peroxide. The variant is also responsive to pH with low and high pKa forms that have distinct spectral properties, which DFT analysis suggests is due to protonation state changes in the newly introduced thiol group, as well as the phenol group. The structure of mCoral reveals that the M66C mutation creates a space within the β-barrel structure that is filled by a water molecule, which makes new polar interactions, includi

SUBMITTER: Zitti A 

PROVIDER: S-EPMC12785414 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature