title: Ethylene glycol improves electrospray ionization efficiency in bottom-up proteomics.
abstract: Liquid chromatography coupled online to nano-electrospray ionization (nESI) tandem mass spectrometry is the analytical workhorse in the field of proteome research. Dimethyl sulfoxide (DMSO) was recently shown to improve nESI efficiency by a factor of three to ten thus improving the sensitivity and coverage of proteomic experiments. However, relatively few investigations into which solvent additives promote nESI response have been performed at a proteomic scale. Here, we systematically evaluated the concept by screening about 30 compounds with various physico-chemical properties. Detailed further analysis showed that ethylene glycol performed similarly to DMSO and the results indicate that enhancing the nESI response of peptides by simple solvent additives is a valid and promising approach. Ethylene glycol may serve as a viable alternative to DMSO in applications where DMSO has disadvantages. In keeping with nESI theory, the key properties of an effective solvent additive for proteomic applications are a boiling point higher than water, low surface tension, and preferably high polarity for reversed phase LC-MS/MS applications. Graphical Abstract Ethylene glycol substantially improves peptide ionization.
authors.affiliation: Technical University of Munich, Emil-Erlenmeyer-Forum-5, 85354, Freising, Germany.
authors.forename: Peng
authors.initials: P
authors.lastname: Yu
authors.affiliation: Technical University of Munich, Emil-Erlenmeyer-Forum-5, 85354, Freising, Germany.|OmicScouts GmbH, St.-Valentin-Straße 5, 85356, Freising, Germany.
authors.forename: Hannes
authors.initials: H
authors.lastname: Hahne
authors.affiliation: Technical University of Munich, Emil-Erlenmeyer-Forum-5, 85354, Freising, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Wilhelm
authors.affiliation: Technical University of Munich, Emil-Erlenmeyer-Forum-5, 85354, Freising, Germany. kuster@tum.de.|Bavarian Biomolecular Mass Spectrometry Center (BayBioMS), Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany. kuster@tum.de.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kuster
mesh_terms: D002460:Cell Line; D019855:Ethylene Glycol / Q000737:chemistry*; D006801:Humans; D040901:Proteomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D019855:Ethylene Glycol
keywords: Ethylene glycol; LC-MS; Nano-electrospray ionization; Proteomics