title: alpha(2A)-adrenergic receptor derived peptide adsorbates: a G-protein interaction study.
abstract: The affinity of alpha(2A)-adrenergic receptor (alpha(2A)-AR) derived peptide adsorbates for the functional bovine brain G-protein is studied in the search for the minimum sequence recognition. Three short peptides (GPR-i2c, GPR-i3n, and GPR-i3c) are designed to mimic the second and third intracellular loops of the receptor. X-ray photoelectron spectroscopy is used to study the chemical composition of the peptides and the binding strength to the surfaces. Chemisorption of the peptides to the gold substrates is observed. Infrared spectroscopy is used to study the characteristic absorption bands of the peptides. The presence of peptides on the surfaces is verified by prominent amide I and amide II bands. The interaction between the peptides and the G-protein is studied with surface plasmon resonance. It is shown that GPR-i3n has the highest affinity for the G-protein. Equilibrium analysis of the binding shows that the G-protein keeps its native conformation when interacting with GPR-i3c, but during the interaction with GPR-i2c and GPR-i3n the conformation of G-protein is changed, leading to the formation of aggregates and/or multilayers.
authors.affiliation: Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Vahlberg
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Petoral
authors.forename: Carina
authors.initials: C
authors.lastname: Lindell
authors.forename: Klas
authors.initials: K
authors.lastname: Broo
authors.forename: Kajsa
authors.initials: K
authors.lastname: Uvdal
mesh_terms: D000327:Adsorption; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D018341:Receptors, Adrenergic, alpha-2 / Q000737:chemistry* / Q000378:metabolism; D013057:Spectrum Analysis / Q000379:methods; D020349:Surface Plasmon Resonance
chemical_list: D010455:Peptides; D018341:Receptors, Adrenergic, alpha-2; D006046:Gold; D019204:GTP-Binding Proteins