Collision Induced Unfolding: Rapid, Sensitive, Information Rich Stability Measurements

The next generation of medicines will rely heavily upon our ability to quickly assess the structures and stabilities of complex macromolecular machines, as well as the influence of large libraries of conformationally-selective small molecule binders and protein-based biotherapeutics. Such endeavours are nearly insurmountable with current tools.

In this presentation, I discuss recent developments surrounding collision induced unfolding (CIU) methods that aim to bridge this technology gap. CIU uses ion mobility-mass spectrometry (IM-MS) to measure the stability and unfolding pathways of gas-phase proteins, without the need for covalent labels or tagging, and consuming 10-100 times less sample than almost any other label-free technology.

Recent developments in high-throughput CIU screening methods, their ability to track alterations in biomolecular structure as a function of stress, and software developments that seek to enhance CIU information content will be discussed. Furthermore, our efforts that have led to the development of the Agilent 6560C drift tube IM-MS platform will be discussed, focusing on the performance of this platform for applications associated with native IM-MS and CIU.

Presenter: Brandon T. Ruotolo, Ph.D. (University of Michigan)

Brandon T. Ruotolo is currently a Professor in the Department of Chemistry, University of Michigan. He earned his B.S. in Chemistry from Saint Louis University in 1999. Brandon then received his Ph.D. from Texas A&M University in 2004 under the direction of David H. Russell. He did his post-doctoral work at the University of Cambridge with Dame Carol V. Robinson, and was awarded the first ever Waters Research Fellowship in 2008. Brandon moved to the University of Michigan in 2009, where he began his independent career. The Ruotolo research group at the University of Michigan seeks to enable breakthroughs in structural biology and drug discovery by leveraging the potential of ion mobility-mass spectrometry (IM-MS) for the comprehensive, 3D structural analysis of the proteome. To this end, Ruotolo and his team have studied the role of solvation on biomolecular structure, introduced collision induced unfolding (CIU) - a new fingerprinting technology capable of detecting the structural state of protein-ligand complexes and biotherapeutics, developed software packages for the enhanced interpretation and throughput of IM-MS and CIU data, and investigated the structural consequences of small molecule drug-like compounds on amyloid-related peptides. Ruotolo’s work has resulted in ca. 120 peer-reviewed publications, and many awards, including the Eli Lilly Award in Analytical Chemistry, the NSF CAREER award, the ASMS Research Award, the Protein Science Young Investigator Award, and the Agilent Thought Leader Award.