title: 19F NMR spectroscopy monitors ligand binding to recombinantly fluorine-labelled b'x from human protein disulphide isomerase (hPDI).
abstract: We report a protein-observe (19)F NMR-based ligand titration binding study of human PDI b'x with Δ-somatostatin that also emphasises the need to optimise recombinant protein fluorination when using 5- or 6-fluoroindole. This study highlights a recombinant preference for 5-fluoroindole over 6-fluoroindole; most likely due to the influence of fluorine atomic packing within the folded protein structure. Fluorination affords a single (19)F resonance probe to follow displacement of the protein x-linker as ligand is titrated and provides a dissociation constant of 23 ± 4 μM.
authors.affiliation: Protein Science Group, School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK. r.a.williamson@kent.ac.uk m.j.howard@kent.ac.uk.
authors.forename: Rose
authors.initials: R
authors.lastname: Curtis-Marof
authors.forename: Denisa
authors.initials: D
authors.lastname: Doko
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Rowe
authors.forename: Kirsty L
authors.initials: KL
authors.lastname: Richards
authors.forename: Richard A
authors.initials: RA
authors.lastname: Williamson
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Howard
mesh_terms: D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D005461:Fluorine / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D019704:Protein Disulfide-Isomerases / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry*; D017186:Titrimetry
chemical_list: D008024:Ligands; D011994:Recombinant Proteins; D005461:Fluorine; D019704:Protein Disulfide-Isomerases