Develop a Sensitive Method for Probing Mutation Induced Changes in Protein Structure & Stability

The techniques of making site-directed mutants of proteins is widely applied in protein structure-function studies. However, such changes often met with scrutiny due to unknown mutational effects on protein structure. We developed an experimental method to tackle such scrutiny based on an advanced Fourier Transform infrared (FTIR) system. We will report results of four site-specific mutants (H3Q, H108Q, E46Q, and Y52A) of a bacterial blue light photoreceptor protein with a covalently attached p-coumaric acid as the light detecting chromophore. The results demonstrate that advanced FTIR spectroscopy is a sensitive method for detecting mutation induced changes in protein structure and stability.