Abstract
An analysis of the pH-dependent dissociation and denaturation of a heterodimeric protein is described. Electrospray ionization mass spectrometry (ESI-MS) was utilized to analyze the dissociation and denaturation of the heterodimeric yeast killer toxin SMKT. The two distinct subunits of SMKT noncovalently associate with one another under acidic conditions, but dissociate and are then denatured under neutral and basic conditions. In order to understand the mechanism that controls the unique pH-dependent denaturation mechanism of this protein, a pH titration was performed using ESI-MS. In this report, the MS conditions for the pH-titration and data-analysis procedures are described.
