title: Analysis of intracellular enzyme activity by surface enhanced Raman scattering.
abstract: Dysfunctional intracellular enzymatic activity is believed to be an underlying cause of a myriad of diseases. We present the first use of surface enhanced Raman scattering (SERS) as a detection technique capable of reporting intracellular activity of a specific enzyme. Careful choice of reagents allowed the preparation of high resolution cellular activity maps highlighting the specific conversion of the commonly used ELISA reagent 5-bromo-4-chloro-3-indolyl β-D-galactopyranoside (X-Gal), by wild type β-galactosidase enzymes. Further, through co-addition of X-Gal substrate and inhibitors we were able to demonstrate that intracellular substrate conversion occurred predominantly through an enzymatically specific pathway. The data presented therefore supports the application of SERS probes as sensitive, specific sensors of biochemical activity and demonstrates the use of SERS probes for the first time as beacons capable of high resolution subcellular localisation of native enzymes.
authors.affiliation: Centre for Molecular Nanometrology, WestCHEM, Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK. duncan.graham@strath.ac.uk.
authors.forename: Ross
authors.initials: R
authors.lastname: Stevenson
authors.forename: Sarah
authors.initials: S
authors.lastname: McAughtrie
authors.forename: Laura
authors.initials: L
authors.lastname: Senior
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Stokes
authors.forename: Helen
authors.initials: H
authors.lastname: McGachy
authors.forename: Laurence
authors.initials: L
authors.lastname: Tetley
authors.forename: Paola
authors.initials: P
authors.lastname: Nativo
authors.forename: James M
authors.initials: JM
authors.lastname: Brewer
authors.forename: James
authors.initials: J
authors.lastname: Alexander
authors.forename: Karen
authors.initials: K
authors.lastname: Faulds
authors.forename: Duncan
authors.initials: D
authors.lastname: Graham
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000502:physiology; D007424:Intracellular Fluid / Q000737:chemistry* / Q000201:enzymology*; D008163:Luminescent Measurements / Q000379:methods; D008264:Macrophages / Q000737:chemistry / Q000201:enzymology; D051379:Mice; D008807:Mice, Inbred BALB C; D013059:Spectrum Analysis, Raman / Q000379:methods*; D001616:beta-Galactosidase / Q000032:analysis / Q000378:metabolism
chemical_list: D001616:beta-Galactosidase