Determination of zinc to beta-peptide binding constants with electrospray ionization mass spectrometry.
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.
Wortmann
Arno
A
Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, CH-8093 Zurich, Switzerland.
Rossi
Francesco
F
Lelais
Gerald
G
Zenobi
Renato
R
D009842:Oligopeptides / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D015032:Zinc / Q000737:chemistry*
D009842:Oligopeptides; D015032:Zinc