TY  - JOUR
AU  - Marchese, Roberto
AU  - Grandori, Rita
AU  - Carloni, Paolo
AU  - Raugei, Simone
TI  - A Computational Model for Protein Ionization by Electrospray Based on Gas-Phase Basicity
JO  - Journal of the American Society for Mass Spectrometry
VL  - 23
IS  - 11
SN  - 1879-1123
CY  - New York [u.a.]
PB  - Springer
M1  - FZJ-2015-03625
SP  - 1903 - 1910
PY  - 2012
AB  - Identifying the key factor(s) governing the overall protein charge is crucial for the interpretation of electrospray-ionization mass spectrometry data. Current hypotheses invoke different principles for folded and unfolded proteins. Here, first we investigate the gas-phase structure and energetics of several proteins of variable size and different folds. The conformer and protomer space of these proteins ions is explored exhaustively by hybrid Monte-Carlo/molecular dynamics calculations, allowing for zwitterionic states. From these calculations, the apparent gas-phase basicity of desolvated protein ions turns out to be the unifying trait dictating protein ionization by electrospray. Next, we develop a simple, general, adjustable-parameter-free model for the potential energy function of proteins. The model is capable to predict with remarkable accuracy the experimental charge of folded proteins and its well-known correlation with the square root of protein mass.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000309941700008
DO  - DOI:10.1007/s13361-012-0449-0
UR  - https://juser.fz-juelich.de/record/201320
ER  -