title: Optimising the synthesis, polymer membrane encapsulation and photoreduction performance of Ru(II)- and Ir(III)-bis(terpyridine) cytochrome c bioconjugates.
abstract: Ruthenium(II) and iridium(III) bis(terpyridine) complexes were prepared with maleimide functionalities in order to site-specifically modify yeast iso-1 cytochrome c possessing a single cysteine residue available for modification (CYS102). Single X-ray crystal structures were solved for aniline and maleimide Ru(II) 3 and Ru(II) 4, respectively, providing detailed structural detail of the complexes. Light-activated bioconjugates prepared from Ru(II) 4 in the presence of tris(2-carboxyethyl)-phosphine (TCEP) significantly improved yields from 6% to 27%. Photoinduced electron transfer studies of Ru(II)-cyt c in bulk solution and polymer membrane encapsulated specimens were performed using EDTA as a sacrificial electron donor. It was found that membrane encapsulation of Ru(II)-cyt c in PS140-b-PAA48 resulted in a quantum efficiency of 1.1 ± 0.3 × 10(-3), which was a two-fold increase relative to the bulk. Moreover, Ir(III)-cyt c bioconjugates showed a quantum efficiency of 3.8 ± 1.9 × 10(-1), equivalent to a ∼640-fold increase relative to bulk Ru(II)-cyt c.
authors.affiliation: School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Hvasanov
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Mason
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Goldstein
authors.forename: Mohan
authors.initials: M
authors.lastname: Bhadbhade
authors.forename: Pall
authors.initials: P
authors.lastname: Thordarson
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D002214:Capsules; D060326:Chemistry Techniques, Synthetic; D045304:Cytochromes c / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008567:Membranes, Artificial; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D011137:Polystyrenes / Q000737:chemistry*; D011487:Protein Conformation; D011725:Pyridines / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D000179:Acrylates; D002214:Capsules; D008567:Membranes, Artificial; D009942:Organometallic Compounds; D011137:Polystyrenes; D011725:Pyridines; C509855:poly(styrene-b-acrylic acid); D007495:Iridium; D012428:Ruthenium; D045304:Cytochromes c; C023666:pyridine