title: Absolute quantification of norovirus capsid protein in food, water, and soil using synthetic peptides with electrospray and MALDI mass spectrometry.
abstract: Norovirus infections are one of the most prominent public health problems of microbial origin in the U.S. and other industrialized countries. Surveillance is necessary to prevent secondary infection, confirm successful cleanup after outbreaks, and track the causative agent. Quantitative mass spectrometry, based on absolute quantitation with stable-isotope labeled peptides, is a promising tool for norovirus monitoring because of its speed, sensitivity, and robustness in the face of environmental inhibitors. In the current study, we present two new methods for the detection of the norovirus genogroup I capsid protein using electrospray and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The peptide TLDPIEVPLEDVR was used to quantify norovirus-like particles down to 500 attomoles with electrospray and 100 attomoles with MALDI. With MALDI, we also demonstrate a detection limit of 1 femtomole and a quantitative dynamic range of 5 orders of magnitude in the presence of an environmental matrix effect. Due to the rapid processing time and applicability to a wide range of environmental sample types (bacterial lysate, produce, milk, soil, and groundwater), mass spectrometry-based absolute quantitation has a strong potential for use in public health and environmental sciences.
authors.affiliation: Center for Environmental Security and Security Defense Systems Initiative, The Biodesign Institute, Arizona State University, 781 E. Terrace Mall, Tempe, AZ 85287-5904, USA.
authors.forename: Erica M
authors.initials: EM
authors.lastname: Hartmann
authors.affiliation: Department of Environmental Health Sciences, The Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Colquhoun
authors.affiliation: Department of Environmental Health Sciences, The Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Kellogg J
authors.initials: KJ
authors.lastname: Schwab
authors.affiliation: Center for Environmental Security and Security Defense Systems Initiative, The Biodesign Institute, Arizona State University, 781 E. Terrace Mall, Tempe, AZ 85287-5904, USA; Department of Environmental Health Sciences, The Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA. Electronic address: halden@asu.edu.
authors.forename: Rolf U
authors.initials: RU
authors.lastname: Halden
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000032:analysis*; D005516:Food Microbiology; D031985:Fragaria / Q000382:microbiology; D060587:Groundwater / Q000382:microbiology; D018545:Lactuca / Q000382:microbiology; D008892:Milk / Q000382:microbiology; D029322:Norovirus; D010455:Peptides / Q000737:chemistry*; D012988:Soil Microbiology; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014871:Water Microbiology
chemical_list: D036022:Capsid Proteins; D010455:Peptides
keywords: Absolute quantification; Environmental detection; Mass spectrometry; Norovirus