title: Determination of zinc to beta-peptide binding constants with electrospray ionization mass spectrometry.
abstract: We present an improvement of the titration method for binding constant determination with electrospray ionization (ESI) mass spectrometry that is unaffected by differences in ESI response of measured species in solution. The method consists of a calibration and titration, both using an internal standard that allows relative quantitation. This avoids artifacts such as a decrease in overall signal intensity with increasing ligand concentrations, rendering this approach more reliable and meaningful than direct evaluation of ESI peak intensities. We demonstrate the de novo binding constant determination of novel zinc binding beta-peptides, which have been synthesized with the goal of creating secondary structures stabilized by metal complexation.
authors.affiliation: Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, CH-8093 Zurich, Switzerland.
authors.forename: Arno
authors.initials: A
authors.lastname: Wortmann
authors.forename: Francesco
authors.initials: F
authors.lastname: Rossi
authors.forename: Gerald
authors.initials: G
authors.lastname: Lelais
authors.forename: Renato
authors.initials: R
authors.lastname: Zenobi
mesh_terms: D009842:Oligopeptides / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D015032:Zinc / Q000737:chemistry*
chemical_list: D009842:Oligopeptides; D015032:Zinc