Gas-phase hydrogen/deuterium exchange in a traveling wave ion guide for the examination of protein conformations.
Accumulating evidence suggests that solution-phase conformations of small globular proteins and large molecular protein assemblies can be preserved for milliseconds after electrospray ionization. Thus, the study of proteins in the gas phase on this time scale is highly desirable. Here we demonstrate that a traveling wave ion guide (TWIG) of a Synapt mass spectrometer offers a highly suitable environment for rapid and efficient gas-phase hydrogen/deuterium exchange (HDX). Gaseous ND(3) was introduced into either the source TWIG or the TWIG located just after the ion mobility cell, such that ions underwent HDX as they passed through the ND(3) on the way to the time-of-flight analyzer. The extent of deuterium labeling could be controlled by varying the quantity of ND(3) or the speed of the traveling wave. The gas-phase HDX of model peptides corresponded to labeling of primarily fast exchanging sites due to the short labeling times (ranging from 0.1 to 10 ms). In addition to peptides, gas-phase HDX of ubiquitin, cytochrome c, lysozyme, and apomyoglobin were examined. We conclude that HDX of protein ions in a TWIG is highly sensitive to protein conformation, enables the detection of conformers present on submilliseconds time scales, and can readily be combined with ion mobility spectrometry.
Rand
Kasper D
KD
The Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, USA. k.rand@neu.edu
Pringle
Steven D
SD
Murphy
James P
JP
Fadgen
Keith E
KE
Brown
Jeff
J
Engen
John R
JR
D000818:Animals; D002417:Cattle; D002645:Chickens; D045304:Cytochromes c / Q000737:chemistry; D003903:Deuterium / Q000737:chemistry*; D041961:Deuterium Exchange Measurement; D005740:Gases / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry; D009211:Myoglobin / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization; D025801:Ubiquitin / Q000737:chemistry
D005740:Gases; D009211:Myoglobin; D010455:Peptides; D025801:Ubiquitin; D006859:Hydrogen; D045304:Cytochromes c; D003903:Deuterium; D009113:Muramidase