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Photo Marie Skepö

Marie Skepö

Professor

Photo Marie Skepö

Physicochemical characterisation of KEIF€-the intrinsically disordered N-terminal region of magnesium transporter A

Author

  • Stéphanie Jephthah
  • Linda K. Månsson
  • Domagoj Belić
  • Jens Preben Morth
  • Marie Skepö

Summary, in English

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 β-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.

Department/s

  • Computational Chemistry
  • Physical Chemistry
  • LINXS - Institute of advanced Neutron and X-ray Science
  • eSSENCE: The e-Science Collaboration

Publishing year

2020

Language

English

Publication/Series

Biomolecules

Volume

10

Issue

4

Document type

Journal article

Publisher

MDPI AG

Topic

  • Biological Sciences

Keywords

  • Circular dichroism spectroscopy
  • Cryogenic transmission electron microscopy
  • Intrinsically disordered proteins
  • Magnesium transporter
  • Membrane proteins
  • Molecular-dynamics simulations
  • Protein-vesicle interactions
  • Secondary structure
  • Small-angle X-ray scattering

Status

Published

ISBN/ISSN/Other

  • ISSN: 2218-273X