title: Human K10 epithelial keratin is the most abundant protein in airborne dust of both occupied and unoccupied school rooms.
abstract: Previously it was demonstrated that the levels of large particles (>2 micron) and associated bacterial cell envelope markers increase greatly on occupation in schools; it was hypothesized that the source of both was shed human skin. In the current work to test this hypothesis, room air cleaners were used to collect airborne dust (>50-100 mg) from occupied and unoccupied school rooms which was then subjected to proteomic analysis. Proteins were extracted from the dust and separated using two dimensional gel electrophoresis (2D GE). In situ digestion of protein spots with trypsin released peptides, which were subsequently analyzed by matrix assisted laser desorption/deionization, time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry (MALDI-TOF-MS-MS). In Coomassie blue stained gels, a single spot generally dominated the 2D gels; this protein was identified by tandem mass spectrometry as K10 epithelial keratin. The results experimentally confirm previous anecdotal reports that human skin is readily shed into air and suggest that increased levels of microbial markers and large particles observed in occupied rooms are also derived from skin.
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Fox
authors.forename: Elisangela
authors.initials: E
authors.lastname: Castanha
authors.forename: Alvin
authors.initials: A
authors.lastname: Fox
authors.forename: Charles
authors.initials: C
authors.lastname: Feigley
authors.forename: Deborah
authors.initials: D
authors.lastname: Salzberg
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D004391:Dust / Q000032:analysis*; D006801:Humans; D007633:Keratins / Q000032:analysis*; D040901:Proteomics; D012574:Schools; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000393:Air Pollutants; D004391:Dust; D007633:Keratins