Alpha-T244M mutation affects the redox, kinetic, and in vitro folding properties of Paracoccus denitrificans electron transfer flavoprotein

The role of the T244 mutation, introduced into the alpha subunit of Paracoccus denitrificans transfer flavoprotein (ETF), on its kinetic and redox properties has been studied. Results indicate that the mutation had no significant effect on the global structure of ETF, based on its visible and near-ultraviolet absorption and circular dichroism spectra. Tyrosine fluorescence in the mutant protein remains constant even if two tyrosine residues are near the site of the mutation. These findings indicate that changes in the structure of EFT are minor and localized.