Elucidation of the binding sites of sodium dodecyl sulfate to β-lactoglobulin using hydrogen/deuterium exchange mass spectrometry combined with docking simulation
Article first published online: 18 APR 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 25, Issue 10, pages 1429–1436, 30 May 2011
How to Cite
(2011), Elucidation of the binding sites of sodium dodecyl sulfate to β-lactoglobulin using hydrogen/deuterium exchange mass spectrometry combined with docking simulation. Rapid Commun. Mass Spectrom., 25: 1429–1436. doi: 10.1002/rcm.5012
- Issue published online: 18 APR 2011
- Article first published online: 18 APR 2011
- Manuscript Revised: 12 MAR 2011
- Manuscript Accepted: 12 MAR 2011
- Manuscript Received: 24 JAN 2011
- National Science Foundation of China. Grant Numbers: 90713020, 20975103, 21020102039, 21055002
- Chinese Academy of Sciences
Hydrogen/deuterium exchange mass spectrometry (H/DX MS) has become a powerful tool to investigate protein-protein and protein-ligand interactions, but it is still challenging to localize the interaction regions/sites of ligands with pepsin-resistant proteins such as lipocalins. β-Lactoglobulin (BLG), a member of the lipocalin family, can bind a variety of small hydrophobic molecules including retinols, retinoic acids, and long linear fatty acids. However, whether the binding site of linear molecules locates in the external groove or internal cavity of BLG is controversial. In this study we used H/DX MS combined with docking simulation to localize the interaction sites of a tested ligand, sodium dodecyl sulfate (SDS), binding to BLG. H/DX MS results indicated that SDS can bind to both the external and the internal sites in BLG. However, neither of the sites is saturated with SDS, allowing a dynamic ligand exchange to occur between the sites at equilibrium state. Docking studies revealed that SDS forms H-bonds with Lys69 in the internal site and Lys138 and Lys141 in the external site in BLG via the sulfate group, and interacts with the hydrophobic residues valine, leucine, isoleucine and methionine within both of the sites via its hydrocarbon tail, stabilizing the BLG-SDS complex. Copyright © 2011 John Wiley & Sons, Ltd.