title: Fluorophore-assisted light inactivation: a high-throughput tool for direct target validation of proteins.
abstract: To exploit advances in proteomics for drug discovery, high-throughout methods for target validation that directly address the cellular roles of proteins are required. To do this, we have characterized fluorophore-assisted light inactivation (FALI) which uses coherent or diffuse light targeted by fluorescein-labeled probes to inactivate specific proteins. We have shown that it is spatially restricted and tested its efficacy in living cells. FALI is efficient using conventional antibodies and single chain variable fragment phage display antibodies (that are compatible with high-throughput applications). We have shown that singlet oxygen is one of the major components required for FALI-mediated damage. The half-maximal radius of damage is approximately 40 A. FALI causes the specific loss of function of beta 1 integrin in HT-1080 fibrosarcoma cells resulting in a reduction in invasiveness. The efficacy of diffuse light sources (such as a desk lamp) with FALI to inactivate many samples in parallel provides an inexpensive, high-throughput method of wide general applicability for functional proteomics.
authors.affiliation: Xerion Pharmaceuticals, Martinsried, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Beck
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakurai
authors.forename: Brenda K
authors.initials: BK
authors.lastname: Eustace
authors.forename: Gerald
authors.initials: G
authors.lastname: Beste
authors.forename: Robert
authors.initials: R
authors.lastname: Schier
authors.forename: Fritz
authors.initials: F
authors.lastname: Rudert
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Jay
mesh_terms: D000818:Animals; D005354:Fibrosarcoma / Q000473:pathology; D005456:Fluorescent Dyes; D006801:Humans; D007202:Indicators and Reagents; D019012:Integrin beta1 / Q000378:metabolism; D007834:Lasers; D051379:Mice; D018218:Neoplasms, Fibrous Tissue / Q000473:pathology; D019151:Peptide Library; D011506:Proteins / Q000737:chemistry*; D020543:Proteome; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D019012:Integrin beta1; D019151:Peptide Library; D011506:Proteins; D020543:Proteome; D017382:Reactive Oxygen Species; D001616:beta-Galactosidase