title: Determining composition of micron-scale protein deposits in neurodegenerative disease by spatially targeted optical microproteomics.
abstract: Spatially targeted optical microproteomics (STOMP) is a novel proteomics technique for interrogating micron-scale regions of interest (ROIs) in mammalian tissue, with no requirement for genetic manipulation. Methanol or formalin-fixed specimens are stained with fluorescent dyes or antibodies to visualize ROIs, then soaked in solutions containing the photo-tag: 4-benzoylbenzyl-glycyl-hexahistidine. Confocal imaging along with two photon excitation are used to covalently couple photo-tags to all proteins within each ROI, to a resolution of 0.67 µm in the xy-plane and 1.48 µm axially. After tissue solubilization, photo-tagged proteins are isolated and identified by mass spectrometry. As a test case, we examined amyloid plaques in an Alzheimer's disease (AD) mouse model and a post-mortem AD case, confirming known plaque constituents and discovering new ones. STOMP can be applied to various biological samples including cell lines, primary cell cultures, ex vivo specimens, biopsy samples, and fixed post-mortem tissue.
authors.affiliation: Department of Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Hadley
authors.affiliation: Department of Chemical and Systems Biology, Stanford University, Stanford, United States.
authors.forename: Rishi
authors.initials: R
authors.lastname: Rakhit
authors.affiliation: The Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular & Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Canada.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Guo
authors.affiliation: Department of Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: Yulong
authors.identifier: http://orcid.org/0000-0002-6665-677X
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Advanced Optical Microscopy Facility, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
authors.forename: James E N
authors.initials: JE
authors.lastname: Jonkman
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
authors.forename: Joanne
authors.initials: J
authors.lastname: McLaurin
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
authors.forename: Lili-Naz
authors.initials: LN
authors.lastname: Hazrati
authors.affiliation: The Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular & Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Emili
authors.affiliation: Departments of Biochemistry and Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: Avijit
authors.initials: A
authors.lastname: Chakrabartty
mesh_terms: D000818:Animals; D013058:Mass Spectrometry; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods*; D019636:Neurodegenerative Diseases / Q000473:pathology*; D061848:Optical Imaging / Q000379:methods*; D011506:Proteins / Q000032:analysis*; D040901:Proteomics / Q000379:methods*
chemical_list: D011506:Proteins
keywords: biochemistry; biophysics; confocal microscopy; human; mass spectroscopy; mouse; protein folding; protein misfolding; proteomics; structural biology