Studying the mechanical responses of proteins using magnetic tweezers

The mechanical stability of proteins has been extensively studied using AFM as a single-molecule force spectroscopy method. While this has led to many important results, these studies have been mainly limited to fast unfolding at a high-force regime due to the rapid mechanical drift in most AFM stretching experiments. Therefore, there is a gap between the knowledge obtained at a high-force regime and the mechanical properties of proteins at a lower force regime which is often more physiologically relevant. Recent studies have demonstrated that this gap can be addressed by stretching single protein molecules using magnetic tweezers, due to the excellent mechanical stability this technology offers. Here we review magnetic tweezers technology and its current application in studies of the force-dependent stability and interactions of proteins.