title: Spectroscopic studies on peptides and proteins with cysteine-containing heme regulatory motifs (HRM).
abstract: The role of heme as a cofactor in enzymatic reactions has been studied for a long time and in great detail. Recently it was discovered that heme can also serve as a signalling molecule in cells but so far only few examples of this regulation have been studied. In order to discover new potentially heme-regulated proteins, we screened protein sequence databases for bacterial proteins that contain sequence features like a Cysteine-Proline (CP) motif, which is known for its heme-binding propensity. Based on this search we synthesized a series of these potential heme regulatory motifs (HRMs). We used cw EPR spectroscopy to investigate whether these sequences do indeed bind to heme and if the spin state of heme is changed upon interaction with the peptides. The corresponding proteins of two potential HRMs, FeoB and GlpF, were expressed and purified and their interaction with heme was studied by cw EPR and UV-Visible (UV-Vis) spectroscopy.
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Schubert
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Florin
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany.
authors.forename: Fraser
authors.initials: F
authors.lastname: Duthie
authors.affiliation: Pharmaceutical Chemistry I, Institute of Pharmacy, University of Bonn, Brühler Str. 7, D-53119 Bonn, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Henning Brewitz
authors.affiliation: Pharmaceutical Chemistry I, Institute of Pharmacy, University of Bonn, Brühler Str. 7, D-53119 Bonn, Germany.
authors.forename: Toni
authors.initials: T
authors.lastname: Kühl
authors.affiliation: Pharmaceutical Chemistry I, Institute of Pharmacy, University of Bonn, Brühler Str. 7, D-53119 Bonn, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Imhof
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany. Electronic address: hagelueken@pc.uni-bonn.de.
authors.forename: Gregor
authors.initials: G
authors.lastname: Hagelueken
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany. Electronic address: schiemann@pc.uni-bonn.de.
authors.forename: Olav
authors.initials: O
authors.lastname: Schiemann
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D020346:Aquaporins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006418:Heme / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006420:Hemeproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013053:Spectrophotometry / Q000379:methods
chemical_list: D020346:Aquaporins; D027682:Cation Transport Proteins; D029968:Escherichia coli Proteins; C470580:FeoB protein, E coli; D006420:Hemeproteins; D010455:Peptides; D011506:Proteins; C078043:GlpF protein, E coli; D006418:Heme; D003545:Cysteine
keywords: EPR spectroscopy; FeoB; GlpF; Heme-binding; UV–Vis spectroscopy