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. 1995 Mar 28;92(7):2451–2454. doi: 10.1073/pnas.92.7.2451

Gas-phase folding and unfolding of cytochrome c cations.

T D Wood 1, R A Chorush 1, F M Wampler 3rd 1, D P Little 1, P B O'Connor 1, F W McLafferty 1
PMCID: PMC42235  PMID: 7708663

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.

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Selected References

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