title: Reflectance method for simple determination of proteinase activity in microliter samples of a complex serum-like fluid.
abstract: A technique using an optical instrument, a reflectometer, for quantitative determination of proteinase activity in microliter samples of complex serum-like fluids, e.g., crevicular exudate from single sites, was developed. The technique allowed the use of various proteins as enzyme substrate. The reflectometer measures the mass of a layer, such as protein, adsorbed to a reflecting surface. This is done by measuring the reflected light intensity of the p-polarized light beam on a surface. We used methylized silicon surfaces that were coated with fibrinogen, alpha 2-macroglobulin, or hemoglobin as enzyme substrates. The test solution was incubated overnight in a basin made in an agar gel applied on the top of the protein-coated surface. In 82 exudates from periodontitis sites, with pocket depths greater than or equal to 6 mm, fibrinogenolytic activity corresponding to 1 microgram ml-1 of trypsin and pronase P was found in 20% of the samples.
authors.affiliation: Department of Oral Microbiology, Faculty of Odontology, University of Göteborg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Wikström
authors.forename: S
authors.initials: S
authors.lastname: Welin-Klintström
authors.forename: S
authors.initials: S
authors.lastname: Renvert
authors.forename: H
authors.initials: H
authors.lastname: Elwing
mesh_terms: D010450:Endopeptidases / Q000032:analysis*; D005122:Exudates and Transudates / Q000201:enzymology; D005340:Fibrinogen / Q000378:metabolism; D005881:Gingiva / Q000201:enzymology / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D010783:Photometry / Q000379:methods*; D011402:Pronase / Q000032:analysis; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties; D014357:Trypsin / Q000032:analysis; D000511:alpha-Macroglobulins / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D000511:alpha-Macroglobulins; D005340:Fibrinogen; D010450:Endopeptidases; D014357:Trypsin; D011402:Pronase; D012825:Silicon