title: Gas-phase folding and unfolding of cytochrome c cations.
abstract: Water is thought to play a dominant role in protein folding, yet gaseous multiply protonated proteins from which the water has been completely removed show hydrogen/deuterium (H/D) exchange behavior similar to that used to identify conformations in solution. Indicative of the gas-phase accessibility to D2O, multiply-charged (6+ to 17+) cytochrome c cations exchange at six (or more) distinct levels of 64 to 173 out of 198 exchangeable H atoms, with the 132 H level found at charge values 8+ to 17+. Infrared laser heating and fast collisions can apparently induce ions to unfold to exchange at a higher distinct level, while charge-stripping ions to lower charge values yields apparent folding as well as unfolding.
authors.affiliation: Baker Chemistry Laboratory, Cornell University, Ithaca, NY 14853-1301, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Wood
authors.forename: R A
authors.initials: RA
authors.lastname: Chorush
authors.forename: F M
authors.initials: FM
authors.lastname: Wampler
authors.forename: D P
authors.initials: DP
authors.lastname: Little
authors.forename: P B
authors.initials: PB
authors.lastname: O'Connor
authors.forename: F W
authors.initials: FW
authors.lastname: McLafferty
mesh_terms: D000818:Animals; D002412:Cations; D003574:Cytochrome c Group / Q000737:chemistry* / Q000378:metabolism; D003903:Deuterium; D004355:Drug Stability; D005740:Gases; D006736:Horses; D006859:Hydrogen; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D012996:Solutions
chemical_list: D002412:Cations; D003574:Cytochrome c Group; D005740:Gases; D012996:Solutions; D006859:Hydrogen; D003903:Deuterium