Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A
Magnesium transporter A (MgtA) is an active transporter responsible for importing magnesium ions into the cytoplasm of prokaryotic cells. This study focuses on the peptide corresponding to the intrinsically disordered N-terminal region of MgtA, referred to as KEIF. Primary-structure and bioinformati...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-04-01
|
| Series: | Biomolecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-273X/10/4/623 |
| _version_ | 1797570332730589184 |
|---|---|
| author | Stéphanie Jephthah Linda K. Månsson Domagoj Belić Jens Preben Morth Marie Skepö |
| author_facet | Stéphanie Jephthah Linda K. Månsson Domagoj Belić Jens Preben Morth Marie Skepö |
| author_sort | Stéphanie Jephthah |
| collection | DOAJ |
| description | Magnesium transporter A (MgtA) is an active transporter responsible for importing magnesium ions into the cytoplasm of prokaryotic cells. This study focuses on the peptide corresponding to the intrinsically disordered N-terminal region of MgtA, referred to as KEIF. Primary-structure and bioinformatic analyses were performed, followed by studies of the undisturbed single chain using a combination of techniques including small-angle X-ray scattering, circular dichroism spectroscopy, and atomistic molecular-dynamics simulations. Moreover, interactions with large unilamellar vesicles were investigated by using dynamic light scattering, laser Doppler velocimetry, cryogenic transmission electron microscopy, and circular dichroism spectroscopy. KEIF was confirmed to be intrinsically disordered in aqueous solution, although extended and containing little <i>β</i>-structure and possibly PPII structure. An increase of helical content was observed in organic solvent, and a similar effect was also seen in aqueous solution containing anionic vesicles. Interactions of cationic KEIF with anionic vesicles led to the hypothesis that KEIF adsorbs to the vesicle surface through electrostatic and entropic driving forces. Considering this, there is a possibility that the biological role of KEIF is to anchor MgtA in the cell membrane, although further investigation is needed to confirm this hypothesis. |
| first_indexed | 2024-03-10T20:24:25Z |
| format | Article |
| id | doaj.art-a7c19bb8c28c4b8e9231c884964f97f2 |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-10T20:24:25Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-a7c19bb8c28c4b8e9231c884964f97f22023-11-19T21:57:10ZengMDPI AGBiomolecules2218-273X2020-04-0110462310.3390/biom10040623Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter AStéphanie Jephthah0Linda K. Månsson1Domagoj Belić2Jens Preben Morth3Marie Skepö4Division of Theoretical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, SwedenDivision of Theoretical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, SwedenDivision of Physical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, SwedenEnzyme and Protein Chemistry, Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, DenmarkDivision of Theoretical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, SwedenMagnesium transporter A (MgtA) is an active transporter responsible for importing magnesium ions into the cytoplasm of prokaryotic cells. This study focuses on the peptide corresponding to the intrinsically disordered N-terminal region of MgtA, referred to as KEIF. Primary-structure and bioinformatic analyses were performed, followed by studies of the undisturbed single chain using a combination of techniques including small-angle X-ray scattering, circular dichroism spectroscopy, and atomistic molecular-dynamics simulations. Moreover, interactions with large unilamellar vesicles were investigated by using dynamic light scattering, laser Doppler velocimetry, cryogenic transmission electron microscopy, and circular dichroism spectroscopy. KEIF was confirmed to be intrinsically disordered in aqueous solution, although extended and containing little <i>β</i>-structure and possibly PPII structure. An increase of helical content was observed in organic solvent, and a similar effect was also seen in aqueous solution containing anionic vesicles. Interactions of cationic KEIF with anionic vesicles led to the hypothesis that KEIF adsorbs to the vesicle surface through electrostatic and entropic driving forces. Considering this, there is a possibility that the biological role of KEIF is to anchor MgtA in the cell membrane, although further investigation is needed to confirm this hypothesis.https://www.mdpi.com/2218-273X/10/4/623membrane proteinsintrinsically disordered proteinscircular dichroism spectroscopysmall-angle X-ray scatteringcryogenic transmission electron microscopymolecular-dynamics simulations |
| spellingShingle | Stéphanie Jephthah Linda K. Månsson Domagoj Belić Jens Preben Morth Marie Skepö Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A Biomolecules membrane proteins intrinsically disordered proteins circular dichroism spectroscopy small-angle X-ray scattering cryogenic transmission electron microscopy molecular-dynamics simulations |
| title | Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A |
| title_full | Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A |
| title_fullStr | Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A |
| title_full_unstemmed | Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A |
| title_short | Physicochemical Characterisation of KEIF—The Intrinsically Disordered N-Terminal Region of Magnesium Transporter A |
| title_sort | physicochemical characterisation of keif the intrinsically disordered n terminal region of magnesium transporter a |
| topic | membrane proteins intrinsically disordered proteins circular dichroism spectroscopy small-angle X-ray scattering cryogenic transmission electron microscopy molecular-dynamics simulations |
| url | https://www.mdpi.com/2218-273X/10/4/623 |
| work_keys_str_mv | AT stephaniejephthah physicochemicalcharacterisationofkeiftheintrinsicallydisorderednterminalregionofmagnesiumtransportera AT lindakmansson physicochemicalcharacterisationofkeiftheintrinsicallydisorderednterminalregionofmagnesiumtransportera AT domagojbelic physicochemicalcharacterisationofkeiftheintrinsicallydisorderednterminalregionofmagnesiumtransportera AT jensprebenmorth physicochemicalcharacterisationofkeiftheintrinsicallydisorderednterminalregionofmagnesiumtransportera AT marieskepo physicochemicalcharacterisationofkeiftheintrinsicallydisorderednterminalregionofmagnesiumtransportera |