1
|
Hjalte J, Diehl C, Leung AE, Poon JF, Porcar L, Dalgliesh R, Sjögren H, Wahlgren M, Sanchez-Fernandez A. Modulating protein unfolding and refolding via the synergistic association of an anionic and a nonionic surfactant. J Colloid Interface Sci 2024; 672:244-255. [PMID: 38838632 DOI: 10.1016/j.jcis.2024.05.157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/03/2024] [Accepted: 05/21/2024] [Indexed: 06/07/2024]
Abstract
HYPOTHESIS Nonionic surfactants can counter the deleterious effect that anionic surfactants have on proteins, where the folded states are retrieved from a previously unfolded state. However, further studies are required to refine our understanding of the underlying mechanism of the refolding process. While interactions between nonionic surfactants and tightly folded proteins are not anticipated, we hypothesized that intermediate stages of surfactant-induced unfolding could define new interaction mechanisms by which nonionic surfactants can further alter protein conformation. EXPERIMENTS In this work, the behavior of three model proteins (human growth hormone, bovine serum albumin, and β-lactoglobulin) was investigated in the presence of the anionic surfactant sodium dodecylsulfate, the nonionic surfactant β-dodecylmaltoside, and mixtures of both surfactants. The transitions occurring to the proteins were determined using intrinsic fluorescence spectroscopy and far-UV circular dichroism. Based on these results, we developed a detailed interaction model for human growth hormone. Using nuclear magnetic resonance and contrast-variation small-angle neutron scattering, we studied the amino acid environment and the conformational state of the protein. FINDINGS The results demonstrate the key role of surfactant cooperation in defining the conformational state of the proteins, which can shift away or toward the folded state depending on the nonionic-to-ionic surfactant ratio. Dodecylmaltoside, initially a non-interacting surfactant, can unexpectedly associate with sodium dodecylsulfate-unfolded proteins to further impact their conformation at low nonionic-to-ionic surfactant ratio. When this ratio increases, the protein begins to retrieve the folded state. However, the native conformation cannot be fully recovered due to remnant surfactant molecules still adsorbed to the protein. This study demonstrates that the conformational landscape of the protein depends on a delicate interplay between the surfactants, ultimately controlled by the ratio between them, resulting in unpredictable changes in the protein conformation.
Collapse
Affiliation(s)
- Johanna Hjalte
- Food Technology, Engineering and Nutrition, Lund University, Box 124, 221 00 Lund, Sweden
| | - Carl Diehl
- SARomics Biostructures AB, Medicon Village, Scheelevägen 2, 223 81 Lund, Sweden
| | - Anna E Leung
- European Spallation Source, Box 176, 221 00 Lund, Sweden
| | - Jia-Fei Poon
- Food Technology, Engineering and Nutrition, Lund University, Box 124, 221 00 Lund, Sweden; European Spallation Source, Box 176, 221 00 Lund, Sweden
| | - Lionel Porcar
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Rob Dalgliesh
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Helen Sjögren
- Ferring Pharmaceuticals A/S, Amager Strandvej 405, 2770 Kastrup, Denmark
| | - Marie Wahlgren
- Food Technology, Engineering and Nutrition, Lund University, Box 124, 221 00 Lund, Sweden
| | - Adrian Sanchez-Fernandez
- Center for Research in Biological Chemistry and Molecular Materials (CIQUS), Department of Chemical Engineering, Universidade de Santiago de Compostela, Santiago de Compostela 15705, Spain.
| |
Collapse
|
2
|
Krueger S. Small-angle neutron scattering contrast variation studies of biological complexes: Challenges and triumphs. Curr Opin Struct Biol 2022; 74:102375. [PMID: 35490650 PMCID: PMC10988784 DOI: 10.1016/j.sbi.2022.102375] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/09/2022] [Accepted: 03/22/2022] [Indexed: 11/16/2022]
Abstract
Small-angle neutron scattering (SANS) has been a beneficial tool for studying the structure of biological macromolecules in solution for several decades. Continued improvements in sample preparation techniques, including deuterium labeling, neutron instrumentation and complementary techniques such as small-angle x-ray scattering (SAXS), cryo-EM, NMR and x-ray crystallography, along with the availability of more powerful structure prediction algorithms and computational resources has made SANS more important than ever as a means to obtain unique information on the structure of biological complexes in solution. In particular, the contrast variation (CV) technique, which requires a large commitment in both sample preparation and measurement time, has become more practical with the advent of these improved resources. Here, challenges and recent triumphs as well as future prospects are discussed.
Collapse
Affiliation(s)
- Susan Krueger
- NIST Center for Neutron Research, NIST, Gaithersburg, MD, 20899, USA.
| |
Collapse
|
3
|
Vestergaard B, Langkilde AE. Protein fibrillation from another small angle: Sample preparation and SAXS data collection. Methods Enzymol 2022; 677:291-321. [DOI: 10.1016/bs.mie.2022.08.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|