Proton Transfer-Induced Conformational Changes and Melting In Designed Peptides in the Gas Phase

2006 ◽  
Vol 128 (22) ◽  
pp. 7193-7197 ◽  
Author(s):  
Motoya Kohtani ◽  
Thaddeus C. Jones ◽  
Rajagopalan Sudha ◽  
Martin F. Jarrold
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Conformational Changes

An experimental study of the reactivity of the hydroxide anion in the gas phase at room temperature, and its perturbation by hydration

1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Experimental Study ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Gas Phase Reactions ◽  
Flowing Afterglow ◽  
Hydroxide Anion

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.

Gas-phase proton-transfer reactions of the hydronium ion at 298 K

1979 ◽  
Vol 57 (12) ◽  
pp. 1518-1523 ◽  
Author(s):  
Gervase I. Mackay ◽  
Scott D. Tanner ◽  
Alan C. Hopkinson ◽  
Diethard K. Bohme
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Transfer Reactions ◽  
Flowing Afterglow ◽  
Hydronium Ion ◽  
Proton Transfer Reactions

Rate constants measured with the flowing afterglow technique at 298 ± 2 K are reported for the proton-transfer reactions of H3O+ with CH2O, CH3CHO, (CH3)2CO, HCOOH, CH3COOH, HCOOCH3, CH3OH, C2H5OH, (CH3)2O, and CH2CO. Dissociative proton-transfer was observed only with CH3COOH. The rate constants are compared with the predictions of various theories for ion–molecule collisions. The protonation is discussed in terms of the energetics and mechanisms of various modes of dissociation.

scholarly journals Reactions between neutral molecules and cation-radicals in the gas-phase: Can protonation occur without proton transfer?

2015 ◽  
Vol 390 ◽  
pp. 39-48
Author(s):  
Yury V. Vasil’ev ◽  
Douglas F. Barofsky ◽  
Joseph S. Beckman ◽  
Benjamin J. Bythell
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Cation Radicals

Collision-induced elimination of alkenes from deprotonated unsaturated ethers in the gas phase. Reactions involving specific .beta.-proton transfer

1990 ◽  
Vol 112 (7) ◽  
pp. 2537-2541 ◽  
Author(s):  
Russell J. Waugh ◽  
Roger N. Hayes ◽  
Peter C. H. Eichinger ◽  
K. M. Downard ◽  
John H. Bowie
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Gas Phase Reactions

scholarly journals Exploring the conformational landscape of a lanthipeptide synthetase using native mass spectrometry

2020 ◽  
Author(s):  
Nuwani W. Weerasinghe ◽  
Yeganeh Habibi ◽  
Kevin A. Uggowitzer ◽  
Christopher J. Thibodeaux
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Conformational Changes ◽  
Ion Mobility ◽  
Peptide Binding ◽  
Native Mass Spectrometry ◽  
Order Structure ◽  
Conformational Sampling ◽  
Precursor Peptide ◽  
Conformational Landscape

AbstractLanthipeptides are ribosomally-synthesized and post-translationally modified peptide (RiPP) natural products that are biosynthesized in a multistep maturation process by enzymes (lanthipeptide synthetases) that possess relaxed substrate specificity. Recent evidence has suggested that some lanthipeptide synthetases are structurally dynamic enzymes that are allosterically activated by precursor peptide binding, and that conformational sampling of the enzyme-peptide complex may play an important role in defining the efficiency and sequence of biosynthetic events. These “biophysical” processes, while critical for defining the activity and function of the synthetase, remain very challenging to study with existing methodologies. Herein, we show that native nanoelectrospray ionization coupled to ion mobility mass spectrometry (nanoESI-IM-MS) provides a powerful and sensitive means for investigating the conformational landscapes and intermolecular interactions of lanthipeptide synthetases. Namely, we demonstrate that the class II lanthipeptide synthetase (HalM2) and its non-covalent complex with the cognate HalA2 precursor peptide can be delivered into the gas phase in a manner that preserves native structures and intermolecular enzyme-peptide contacts. Moreover, gas phase ion mobility studies of the natively-folded ions demonstrate that peptide binding and mutations to dynamic structural elements of HalM2 alter the conformational landscape of the enzyme, and that the precursor peptide itself exhibits higher order structure in the mass spectrometer. Cumulatively, these data support previous claims that lanthipeptide synthetases are structurally dynamic enzymes that undergo functionally relevant conformational changes in response to precursor peptide binding. This work establishes nanoESI-IM-MS as a versatile approach for unraveling the relationships between protein structure and biochemical function in RiPP biosynthetic systems.

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