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Probing conformational changes of monomeric transthyretin with second derivative fluorescence
We have studied the intrinsic fluorescence spectra of a monomeric variant of human transthyretin (M-TTR), a protein involved in the transport of the thyroid hormone and retinol and associated with various forms of amyloidosis, extending our analysis to the second order derivative of the spectra. Thi...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6662758/ https://www.ncbi.nlm.nih.gov/pubmed/31358790 http://dx.doi.org/10.1038/s41598-019-47230-4 |
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author | Jazaj, Denisa Ghadami, Seyyed Abolghasem Bemporad, Francesco Chiti, Fabrizio |
author_facet | Jazaj, Denisa Ghadami, Seyyed Abolghasem Bemporad, Francesco Chiti, Fabrizio |
author_sort | Jazaj, Denisa |
collection | PubMed |
description | We have studied the intrinsic fluorescence spectra of a monomeric variant of human transthyretin (M-TTR), a protein involved in the transport of the thyroid hormone and retinol and associated with various forms of amyloidosis, extending our analysis to the second order derivative of the spectra. This procedure allowed to identify three peaks readily assigned to Trp41, as the three peaks were also visible in a mutant lacking the other tryptophan (Trp79) and had similar FRET efficiency values with an acceptor molecule positioned at position 10. The wavelength values of the three peaks and their susceptibility to acrylamide quenching revealed that the three corresponding conformers experience different solvent-exposure, polarity of the environment and flexibility. We could monitor the three peaks individually in urea-unfolding and pH-unfolding curves. This revealed changes in the distribution of the corresponding conformers, indicating conformational changes and alterations of the dynamics of the microenvironment that surrounds the associated tryptophan residue in such transitions, but also native-like conformers of such residues in unfolded states. We also found that the amyloidogenic state adopted by M-TTR at mildly low pH has a structural and dynamical microenvironment surrounding Trp41 indistinguishable from that of the fully folded and soluble state at neutral pH. |
format | Online Article Text |
id | pubmed-6662758 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-66627582019-08-02 Probing conformational changes of monomeric transthyretin with second derivative fluorescence Jazaj, Denisa Ghadami, Seyyed Abolghasem Bemporad, Francesco Chiti, Fabrizio Sci Rep Article We have studied the intrinsic fluorescence spectra of a monomeric variant of human transthyretin (M-TTR), a protein involved in the transport of the thyroid hormone and retinol and associated with various forms of amyloidosis, extending our analysis to the second order derivative of the spectra. This procedure allowed to identify three peaks readily assigned to Trp41, as the three peaks were also visible in a mutant lacking the other tryptophan (Trp79) and had similar FRET efficiency values with an acceptor molecule positioned at position 10. The wavelength values of the three peaks and their susceptibility to acrylamide quenching revealed that the three corresponding conformers experience different solvent-exposure, polarity of the environment and flexibility. We could monitor the three peaks individually in urea-unfolding and pH-unfolding curves. This revealed changes in the distribution of the corresponding conformers, indicating conformational changes and alterations of the dynamics of the microenvironment that surrounds the associated tryptophan residue in such transitions, but also native-like conformers of such residues in unfolded states. We also found that the amyloidogenic state adopted by M-TTR at mildly low pH has a structural and dynamical microenvironment surrounding Trp41 indistinguishable from that of the fully folded and soluble state at neutral pH. Nature Publishing Group UK 2019-07-29 /pmc/articles/PMC6662758/ /pubmed/31358790 http://dx.doi.org/10.1038/s41598-019-47230-4 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Jazaj, Denisa Ghadami, Seyyed Abolghasem Bemporad, Francesco Chiti, Fabrizio Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title | Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title_full | Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title_fullStr | Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title_full_unstemmed | Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title_short | Probing conformational changes of monomeric transthyretin with second derivative fluorescence |
title_sort | probing conformational changes of monomeric transthyretin with second derivative fluorescence |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6662758/ https://www.ncbi.nlm.nih.gov/pubmed/31358790 http://dx.doi.org/10.1038/s41598-019-47230-4 |
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