Low-temperature librations and dynamical transition in proteins at differing hydration levels
Hydration of water affects the dynamics and in turn the activity of biomacromolecules. We investigated the dependence of the librational oscillations and the dynamical transition on the hydrating conditions of two globular proteins with different structure and size, namely β-lactoglobulin (βLG) and...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2022-03-01
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| Series: | Biomolecular Concepts |
| Online Access: | https://doi.org/10.1515/bmc-2022-0007 |
| _version_ | 1811203724321751040 |
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| author | Aloi Erika Bartucci Rosa Guzzi Rita |
| author_facet | Aloi Erika Bartucci Rosa Guzzi Rita |
| author_sort | Aloi Erika |
| collection | DOAJ |
| description | Hydration of water affects the dynamics and in turn the activity of biomacromolecules. We investigated the dependence of the librational oscillations and the dynamical transition on the hydrating conditions of two globular proteins with different structure and size, namely β-lactoglobulin (βLG) and human serum albumin (HSA), by spin-label electron paramagnetic resonance (EPR) in the temperature range of 120–270 K. The proteins were spin-labeled with 5-maleimide spin-label on free cysteins and prepared in the lyophilized state, at low (h = 0.12) and full (h = 2) hydration levels in buffer. The angular amplitudes of librations are small and almost temperature independent for both lyophilized proteins. Therefore, in these samples, the librational dynamics is restricted and the dynamical transition is absent. In the small and compact beta-structured βLG, the angular librational amplitudes increase with temperature and hydrating conditions, whereas hydration-independent librational oscillations whose amplitudes rise with temperature are recorded in the large and flexible alpha-structured HSA. Both βLG and HSA at low and fully hydration levels undergo the dynamical transition at about 230 K. The overall results indicate that protein librational dynamics is activated at the low hydration level h = 0.12 and highlight biophysical properties that are common to other biosamples at cryogenic temperatures. |
| first_indexed | 2024-04-12T03:01:03Z |
| format | Article |
| id | doaj.art-a4443e3228184416b590b3f7830ed4bc |
| institution | Directory Open Access Journal |
| issn | 1868-503X |
| language | English |
| last_indexed | 2024-04-12T03:01:03Z |
| publishDate | 2022-03-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Biomolecular Concepts |
| spelling | doaj.art-a4443e3228184416b590b3f7830ed4bc2022-12-22T03:50:41ZengDe GruyterBiomolecular Concepts1868-503X2022-03-01131818810.1515/bmc-2022-0007Low-temperature librations and dynamical transition in proteins at differing hydration levelsAloi Erika0Bartucci Rosa1Guzzi Rita2Department of Physics, Molecular Biophysics Laboratory, University of Calabria, 87036 Rende, ItalyDepartment of Chemistry and Chemical Technologies, Molecular Biophysics Laboratory, University of Calabria, 87036 Rende, ItalyDepartment of Physics, Molecular Biophysics Laboratory, University of Calabria, 87036 Rende, ItalyHydration of water affects the dynamics and in turn the activity of biomacromolecules. We investigated the dependence of the librational oscillations and the dynamical transition on the hydrating conditions of two globular proteins with different structure and size, namely β-lactoglobulin (βLG) and human serum albumin (HSA), by spin-label electron paramagnetic resonance (EPR) in the temperature range of 120–270 K. The proteins were spin-labeled with 5-maleimide spin-label on free cysteins and prepared in the lyophilized state, at low (h = 0.12) and full (h = 2) hydration levels in buffer. The angular amplitudes of librations are small and almost temperature independent for both lyophilized proteins. Therefore, in these samples, the librational dynamics is restricted and the dynamical transition is absent. In the small and compact beta-structured βLG, the angular librational amplitudes increase with temperature and hydrating conditions, whereas hydration-independent librational oscillations whose amplitudes rise with temperature are recorded in the large and flexible alpha-structured HSA. Both βLG and HSA at low and fully hydration levels undergo the dynamical transition at about 230 K. The overall results indicate that protein librational dynamics is activated at the low hydration level h = 0.12 and highlight biophysical properties that are common to other biosamples at cryogenic temperatures.https://doi.org/10.1515/bmc-2022-0007 |
| spellingShingle | Aloi Erika Bartucci Rosa Guzzi Rita Low-temperature librations and dynamical transition in proteins at differing hydration levels Biomolecular Concepts |
| title | Low-temperature librations and dynamical transition in proteins at differing hydration levels |
| title_full | Low-temperature librations and dynamical transition in proteins at differing hydration levels |
| title_fullStr | Low-temperature librations and dynamical transition in proteins at differing hydration levels |
| title_full_unstemmed | Low-temperature librations and dynamical transition in proteins at differing hydration levels |
| title_short | Low-temperature librations and dynamical transition in proteins at differing hydration levels |
| title_sort | low temperature librations and dynamical transition in proteins at differing hydration levels |
| url | https://doi.org/10.1515/bmc-2022-0007 |
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