Back to Search Start Over

Ions from Solution to the Gas Phase: A Molecular Dynamics Simulation of the Structural Evolution of Substance P during Desolvation of Charged Nanodroplets Generated by Electrospray Ionization

Authors :
Nicole D. Wagner
Doyong Kim
David E. Clemmer
Kerry M. Wooding
David H. Russell
Source :
Journal of the American Chemical Society. 139:2981-2988
Publication Year :
2017
Publisher :
American Chemical Society (ACS), 2017.

Abstract

Molecular dynamics (MD) simulations are used to model changes in the conformational preferences of a model peptide during the transition from a hydrated environment (charged nanodroplet generated by electrospray ionization) to the solvent-free peptide ion. The charged droplet consists of ∼2400 water molecules, 22 hydronium ions, and 10 chloride and contains a single Substance P (SP) [SP + 3H]3+ ion (SP3+; amino acid sequence RPKPQQFFGLM-NH2). Initially, droplet shrinkage involves a combination of solvent evaporation and ejection of excess charge, primarily hydronium ions. Further droplet shrinkage leads to a series of fission events, which includes the loss of some Cl– ions. SP3+ ions adapt to the smaller size droplet through small conformational changes that result in coiling of the hydrophobic C-terminus of the peptide on or near the droplet surface, intramolecular interactions involving the hydrophilic N-terminus of the peptide, and water-mediated interactions between the SP3+ ion and H3O+ and Cl– ions...

Details

ISSN :
15205126 and 00027863
Volume :
139
Database :
OpenAIRE
Journal :
Journal of the American Chemical Society
Accession number :
edsair.doi.dedup.....69513910ca660352000c7e780cbe7fc6
Full Text :
https://doi.org/10.1021/jacs.6b10731