Related Experiment Video
Updated: Feb 11, 2026

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
Published on: April 17, 2017
Quantification of Protein-Ligand Interactions by Laser Electrospray Mass Spectrometry
Jieutonne J Archer1, Santosh Karki1, Fengjian Shi1
1Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA.
Abstract:
Laser electrospray mass spectrometry (LEMS) measurement of the dissociation constant (Kd) for hen egg white lysozyme (HEWL) and N,N',N″-triacetylchitotriose (NAG3) revealed an apparent Kd value of 313.2 ± 25.9 μM for the ligand titration method. Similar measurements for N,N',N″,N″'-tetraacetylchitotetraose (NAG4) revealed an apparent Kd of 249.3 ± 13.6 μM. An electrospray ionization mass spectrometry (ESI-MS) experiment determined a Kd value of 9.8 ± 0.6 μM. In a second LEMS approach, a calibrated measurement was used to determine a Kd value of 6.8 ± 1.5 μM for NAG3. The capture efficiency of LEMS was measured to be 3.6 ± 1.8% and is defined as the fraction of LEMS sample detected after merging with the ESI plume. When the dilution is factored into the ligand titration measurement, the adjusted Kd value was 11.3 μM for NAG3 and 9.0 μM for NAG4. The calibration method for measuring Kd developed in this study can be applied to solutions containing unknown analyte concentrations. Graphical Abstract.
More Related Videos
Related Concept Videos
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Mass Spectrometry: Overview
Tandem Mass Spectrometry
Mass Spectrometry of Amines
Mass Spectrometry: Isotope Effect

