title: Use of engineered unique cysteine residues to facilitate oriented coupling of proteins directly to a gold substrate.
abstract: A prerequisite for any "lab on a chip" device that utilizes an electrical signal from the sensor protein is the ability to attach the protein in a specific orientation onto a conducting substrate. Here, we demonstrate the covalent attachment to a gold surface of light-harvesting membrane proteins, from Rhodobacter sphaeroides, via cysteine (Cys) residues engineered on either the cytoplasmic or periplasmic face. This simple directed attachment is superior in its ability to retain light-harvesting complex (LHC) function, when compared to a similar attachment procedure utilizing a self-assembled monolayer on gold. LH 1 has previously been observed to have superior photostability over LH 2 (Magis et al. [2010] Biochim. Biophys. Acta, 1798, 637-645); this characteristic is maintained even with the introduction of Cys residues.
authors.affiliation: Department of Biophysics, Leiden University, Leiden, The Netherlands.
authors.forename: Gerhard J
authors.initials: GJ
authors.lastname: Magis
authors.forename: John D
authors.initials: JD
authors.lastname: Olsen
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Reynolds
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Leggett
authors.forename: C Neil
authors.initials: CN
authors.lastname: Hunter
authors.forename: Thijs J
authors.initials: TJ
authors.lastname: Aartsma
authors.forename: Raoul N
authors.initials: RN
authors.lastname: Frese
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D056656:Lab-On-A-Chip Devices; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018625:Microscopy, Atomic Force; D016297:Mutagenesis, Site-Directed; D055668:Photochemical Processes / Q000528:radiation effects; D011485:Protein Binding; D012242:Rhodobacter sphaeroides / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D006046:Gold; D003545:Cysteine