An enhanced approach for engineering thermally stable proteins using yeast display

Many biotechnology applications require the evolution of enhanced protein stability. Using polymerase chain reaction-based recovery of engineered clones during the screen enrichment phase, we describe a yeast display method capable of yielding engineered proteins having thermal stability that substantially exceeds the viability threshold of the yeast host. To this end, yeast-enhanced green fluorescent protein destabilized by dual-loop insertion was engineered to possess a substantially enhanced resistance to thermal denaturation at 70°C. Stabilized proteins were secreted, purified and found to have three- to six-fold increased resistance to thermal denaturation. The validated method enables yeast display-based screens in previously inaccessible regions of the fitness landscape.