Gas-phase folding and unfolding of cytochrome c cations.
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.
Wood
T D
TD
Baker Chemistry Laboratory, Cornell University, Ithaca, NY 14853-1301, USA.
Chorush
R A
RA
Wampler
F M
FM
Little
D P
DP
O'Connor
P B
PB
McLafferty
F W
FW
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
D002412:Cations; D003574:Cytochrome c Group; D005740:Gases; D012996:Solutions; D006859:Hydrogen; D003903:Deuterium