RT Journal Article
T1 Modulating protein unfolding and refolding via the synergistic association of an anionic and a nonionic surfactant
A1 Hjalte, Johanna
A1 Dielh, Carl
A1 Leung, Anna E.
A1 Poon, Jia-Fei
A1 Porcar, Lionel
A1 Dalgliesh, Robert
A1 Sjögren, Helen
A1 Wahlgren, Marie
A1 Sánchez Fernández, Adrián
K1 Protein unfolding
K1 Protein folding
K1 Nonionic surfactant
K1 Anionic surfactants
AB HypothesisNonionic 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.ExperimentsIn 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.FindingsThe 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
PB Elsevier
SN 0021-9797
YR 2024
FD 2024-05-22
LK http://hdl.handle.net/10347/34983
UL http://hdl.handle.net/10347/34983
LA eng
NO Journal of Colloid and Interface Science 672 (2024) Pages 244-255
NO The research in this study was performed with national support from Vinnova – Swedish Governmental Agency for Innovation Systems within the NextBioForm Competence Centre. Part of this work is based upon experiments performed on the Larmor instrument at the ISIS Neutron and Muon Source, Harwell (UK), and on the D22 instrument at the Institut Laue-Langevin (ILL), Grenoble (France) (experiment numbers: ISIS – RB2010630; ILL– 9-13-948) [60], [61]. Also, the authors thank the Swedish NMR Centre for instrument access and help with the experimental setup. The deuterated DDM samples were synthesized by the DEMAX platform at the European Spallation Source ERIC as a result of proposal YGZX8PCG. The persistent identifier for the samples is doi: 10.5281/zenodo.3496941. The authors gratefully acknowledge the Partnership for Soft Condensed Matter (PSCM) for providing access to the laboratories. This work benefited from the use of the SasView application, originally developed under NSF award DMR-0520547. SasView contains code developed with funding from the European Union’s Horizon 2020 research and innovation programme under the SINE2020 project, grant agreement no 654000
DS Minerva
RD 4 may 2026