Beyond the detergent effect: a binding site for sodium dodecyl sulfate (SDS) in mammalian apoferritin
- University of Pennsylvania, Philadelphia, Pennsylvania (United States)
- Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)
Using X-ray crystallography and isothermal titration calorimetry, we show that sodium dodecyl sulfate (SDS) binds specifically to a pre-formed internal cavity in horse-spleen apoferritin. Although sodium dodecyl sulfate (SDS) is widely used as an anionic detergent, it can also exert specific pharmacological effects that are independent of the surfactant properties of the molecule. However, structural details of how proteins recognize SDS are scarce. Here, it is demonstrated that SDS binds specifically to a naturally occurring four-helix bundle protein: horse apoferritin. The X-ray crystal structure of the apoferritin–SDS complex was determined at a resolution of 1.9 Å and revealed that the SDS binds in an internal cavity that has previously been shown to recognize various general anesthetics. A dissociation constant of 24 ± 9 µM at 293 K was determined by isothermal titration calorimetry. SDS binds in this cavity by bending its alkyl tail into a horseshoe shape; the charged SDS head group lies in the opening of the cavity at the protein surface. This crystal structure provides insights into the protein–SDS interactions that give rise to binding and may prove useful in the design of novel SDS-like ligands for some proteins.
- OSTI ID:
- 22351256
- Journal Information:
- Acta Crystallographica. Section D: Biological Crystallography, Vol. 68, Issue Pt 5; Other Information: PMCID: PMC3335284; PMID: 22525747; PUBLISHER-ID: be5194; OAI: oai:pubmedcentral.nih.gov:3335284; Copyright (c) International Union of Crystallography 2012; Country of input: International Atomic Energy Agency (IAEA); ISSN 0907-4449
- Country of Publication:
- Denmark
- Language:
- English
Similar Records
Backbone dynamics of a model membrane protein: assignment of the carbonyl carbon /sup 13/C NMR resonances in detergent-solubilized M13 coat protein
Effect of the composition of sodium dodecyl sulfate preparations on the renaturation of enzymes after polyacrylamide gel electrophoresis