Basic Information

Abstract Number: 260 - 5
Author Name: David E Clemmer - Indiana University
Session Title: Pittsburgh Conference Achievement Award
Event Type: Awards
Event Title: Developing Techniques for Following Transitions Between Conformational States

Presider Name:Jane Chan
Affiliation:Bechtel Bettis, Inc.

Date: Monday, March 18, 2013
Start Time: 09:20 AM (Slot #5)
Location: 114

Abstract Content

The structures of macromolecules are often described as native or denatured. While the native state implies a key structural feature that is capable of biological function, much less is implied from the term denatured. In their 1954 paper "Conformations of Proteins", Lumry and Eyring inferred that the term denatured had "...acquired so many other meanings as to become virtually useless". In large part, the lack of progress in the last 50 years in understanding non-native structures is the dearth of analytical techniques for probing them. In this talk we describe the development of multidimensional ion mobility spectrometry techniques for following transitions between conformations of macromolecular ions in the gas phase. The approach is to inject a short pulse of ions produced by electrospray ionization into a drift tube containing an inert buffer gas. The distribution of structures separates based on differences in the mobilities. It is possible to select specific states, expose these to energizing collisions, and then follow the new structures that are established by monitoring their mobilities in additional drift tubes. This talk will highlight the ubiquitin system. It is possible to follow many different conformational changes. Recently we have been able to map these gas-phase data back to populations of structures that are present in solution. The ability to follow pathways between structures appears to be useful for refining mobility-based structural assignments. Finally, understanding how structures change will be important for developing next generation mobility instruments that are capable of higher resolving powers.