Grant: CIHR Fellowship

Cardiomyopathy, a major contributor to heart failure, is a heart muscle disease that reduces the heart's ability to pump blood. The elastic properties of the cardiac muscle protein titin are thought to be closely associated with this disease. Previous studies have shown that point mutations can significantly destabilize the folded domains of titin and alter the elastic properties of titin. Such mutations have been predicted to likely cause cardiomyopathy. Here we propose to combine protein engineering with single molecule force spectroscopy (SMFS) techniques to study the role of titin elasticity in cardiomyopathy. We will first use construct point mutants of Ig modules that are predicted to be disease-causing. Then we will employ SMFS to mechanically unfold the protein to determine its mechanical stability and folding/unfolding properties. These results will allow us to evaluate the effect of mutations on titin elasticity, and correlate this effect with their disease-causing potential. This research will shed light on the role of titin elasticity in cardiomyopathy, and help establish mechanical phenotype of Ig domains as a functional tool to evaluate the cardiomyopathy-causing potential of missense mutants of I band titin.