High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA
During infection, the bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae employ ATP-binding cassette (ABC) transporters to acquire Mn(II), an essential nutrient, from the host environment. Staphylococcal MntABC and streptococcal PsaABC attract the attention of the biophysical and...
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| Format: | Article |
| Language: | English |
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American Chemical Society (ACS)
2020
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| Online Access: | https://hdl.handle.net/1721.1/125969 |
| _version_ | 1826192389995233280 |
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| author | Gagnon, Derek M. Hadley, Rose Currier Ozarowski, Andrew Nolan, Elizabeth Marie Britt, R. David |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Gagnon, Derek M. Hadley, Rose Currier Ozarowski, Andrew Nolan, Elizabeth Marie Britt, R. David |
| author_sort | Gagnon, Derek M. |
| collection | MIT |
| description | During infection, the bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae employ ATP-binding cassette (ABC) transporters to acquire Mn(II), an essential nutrient, from the host environment. Staphylococcal MntABC and streptococcal PsaABC attract the attention of the biophysical and bacterial pathogenesis communities because of their established importance during infection. Previous biophysical examination of Mn(II)-MntC and Mn(II)-PsaA using continuous-wave (≈9 GHz) electron paramagnetic resonance (EPR) spectroscopy revealed broad, difficult-to-interpret spectra (Hadley et al. J. Am. Chem. Soc. 2018, 140, 110-113). Herein, we employ high-frequency (>90 GHz), high-field (>3 T) EPR spectroscopy to investigate the Mn(II)-binding sites of these proteins and determine the spin Hamiltonian parameters. Our analyses demonstrate that the zero-field splitting (ZFS) is large for Mn(II)-MntC and Mn(II)-PsaA at +2.72 and +2.87 GHz, respectively. The measured 55Mn hyperfine coupling values for Mn(II)-MntC and Mn(II)-PsaA of 241 and 236 MHz, respectively, demonstrate a more covalent interaction between Mn(II) and the protein compared to Mn(II) in aqueous solution (≈265 MHz). These studies indicate that MntC and PsaA bind Mn(II) in a similar coordination geometry. Comparison of the ZFS values determined herein with those ascertained for other Mn(II) proteins suggests that the Mn(II)-MntC and Mn(II)-PsaA coordination spheres are not five-coordinate in solution. ©2019 American Chemical Society. |
| first_indexed | 2024-09-23T09:10:58Z |
| format | Article |
| id | mit-1721.1/125969 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T09:10:58Z |
| publishDate | 2020 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1259692022-09-26T10:59:48Z High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA Gagnon, Derek M. Hadley, Rose Currier Ozarowski, Andrew Nolan, Elizabeth Marie Britt, R. David Massachusetts Institute of Technology. Department of Chemistry During infection, the bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae employ ATP-binding cassette (ABC) transporters to acquire Mn(II), an essential nutrient, from the host environment. Staphylococcal MntABC and streptococcal PsaABC attract the attention of the biophysical and bacterial pathogenesis communities because of their established importance during infection. Previous biophysical examination of Mn(II)-MntC and Mn(II)-PsaA using continuous-wave (≈9 GHz) electron paramagnetic resonance (EPR) spectroscopy revealed broad, difficult-to-interpret spectra (Hadley et al. J. Am. Chem. Soc. 2018, 140, 110-113). Herein, we employ high-frequency (>90 GHz), high-field (>3 T) EPR spectroscopy to investigate the Mn(II)-binding sites of these proteins and determine the spin Hamiltonian parameters. Our analyses demonstrate that the zero-field splitting (ZFS) is large for Mn(II)-MntC and Mn(II)-PsaA at +2.72 and +2.87 GHz, respectively. The measured 55Mn hyperfine coupling values for Mn(II)-MntC and Mn(II)-PsaA of 241 and 236 MHz, respectively, demonstrate a more covalent interaction between Mn(II) and the protein compared to Mn(II) in aqueous solution (≈265 MHz). These studies indicate that MntC and PsaA bind Mn(II) in a similar coordination geometry. Comparison of the ZFS values determined herein with those ascertained for other Mn(II) proteins suggests that the Mn(II)-MntC and Mn(II)-PsaA coordination spheres are not five-coordinate in solution. ©2019 American Chemical Society. NIH (grant no. R35GM126961) NIH (grant no. R01GM118695) 2020-06-23T22:36:39Z 2020-06-23T22:36:39Z 2019-05 2019-04 2020-06-19T17:51:42Z Article http://purl.org/eprint/type/JournalArticle 1520-5207 https://hdl.handle.net/1721.1/125969 Gagnon, Derek M. et al., "High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA." Journal of Physical Chemistry B 123, 23 (June 2019): p. 4929–34 doi. 10.1021/acs.jpcb.9b03633 ©2019 Authors en https://dx.doi.org/10.1021/ACS.JPCB.9B03633 Journal of Physical Chemistry B Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) PMC |
| spellingShingle | Gagnon, Derek M. Hadley, Rose Currier Ozarowski, Andrew Nolan, Elizabeth Marie Britt, R. David High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title | High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title_full | High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title_fullStr | High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title_full_unstemmed | High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title_short | High-Field EPR Spectroscopic Characterization of Mn(II) Bound to the Bacterial Solute-Binding Proteins MntC and PsaA |
| title_sort | high field epr spectroscopic characterization of mn ii bound to the bacterial solute binding proteins mntc and psaa |
| url | https://hdl.handle.net/1721.1/125969 |
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