Internal energy distribution of peptides in electrospray ionization : ESI and collision-induced dissociation spectra calculation.
The internal energy of ions and the timescale play fundamental roles in mass spectrometry. The main objective of this study is to estimate and compare the internal energy distributions of different ions (different nature, degree of freedom 'DOF' and fragmentations) produced in an electrospray source (ESI) of a triple-quadrupole instrument (Quattro I Micromass). These measurements were performed using both the Survival Yield method (as proposed by De Pauw) and the MassKinetics software (kinetic model introduced by Vékey). The internal energy calibration is the preliminary step for ESI and collision-induced dissociation (CID) spectra calculation. meta-Methyl-benzylpyridinium ion and four protonated peptides (YGGFL, LDIFSDF, LDIFSDFR and RLDIFSDF) were produced using an electrospray source. These ions were used as thermometer probe compounds. Cone voltages (V(c)) were linearly correlated with the mean internal energy values (<E(int) >) carried by desolvated ions. These mean internal energy values seem to be slightly dependent on the size of the studied ion. ESI mass spectra and CID spectra were then simulated using the MassKinetics software to propose an empirical equation for the mean internal energy (<E(int) >) versus cone voltage (V(c)) for different source temperatures (T): < E(int) > = [405 x 10(-6) - 480 x 10(-9) (DOF)] V(c)T + E(therm)(T). In this equation, the E(therm)(T) parameter is the mean internal energy due to the source temperature at 0 V(c).
Pak
Alireza
A
Université Pierre et Marie Curie-Paris6, CNRS, UMR 7613, Synthèse, Structure et Fonction de Molécules Bioactives, groupe de spectrométrie de masse, 4 place Jussieu, 75252 Paris cedex 05, France.
Lesage
Denis
D
Gimbert
Yves
Y
Vékey
Károly
K
Tabet
Jean-Claude
JC
D007477:Ions / Q000032:analysis* / Q000737:chemistry; D008956:Models, Chemical; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry; D011522:Protons; D011726:Pyridinium Compounds / Q000032:analysis / Q000737:chemistry; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*
D007477:Ions; D010446:Peptide Fragments; D011522:Protons; D011726:Pyridinium Compounds