Force spectroscopy studies of protein folding and binding

Understanding the ways proteins fold, unfold, and bind to their substrates are central objectives in structural biology. To gain insights into these processes, we mainly use force spectroscopy. Like other single-molecule techniques, this method allows extracting information which is masked by ensemble averaging, enabling access into the shape and roughness of the energy landscapes that underlie protein reactions. In addition, it allows for a straightforward comparison to molecular dynamics pulling simulations in which unfolding or unbinding are induced by the application of a (virtual) mechanical force. Such simulations, in turn, enable to visualize the processes with an atomic or near-atomic resolution. In our studies we focus on proteins belonging to the soluble phase of the nucleocytoplasmic transport machinery, the small enzyme acylphosphatase (AcP), and one of the subunits of the interferon-α receptor (IFNAR1). More recently, we began to employ conventional bulk methods in conjunction with protein engineering and molecular dynamics simulations to study the effects of loop length on protein stability, folding, and function.

Current projects:

• Effect of loop length on AcP conformational stability, foldability, and catalysis.

• Unfolding mechanics of IFNAR1 in the presence and absence of interferon.