title: A turbidimetric method for measuring the activity of trypsin and its inhibition.
abstract: Microscopic poly(styrene-divinylbenzene) beads coated with a monomolecular film of fibrinogen agglutinate when stirred in the presence of thrombin, a consequence of interbead fibrin formation. Trypsin, by digesting bead-bound fibrin, dissociates bead aggregates at a rate proportional to the amount of enzyme activity. The agglutination of beads and the dissociation of bead aggregates can be monitored turbidimetrically using a platelet aggregometer or other photometric device equipped with a stirred cell. We have exploited the behavior of aggregates of fibrin-coated beads to develop a rapid, sensitive, and accurate method for measuring the activity of trypsin and its inhibition, in aqueous media, including serum. The new method yields serum antitrypsin activity levels that correlate well with immunological levels of alpha1-antitrypsin and, thus, may prove useful for assessing antitrypsin activity in clinical specimens.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45267-0529, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Walker
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Retzinger
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Retzinger
mesh_terms: D001665:Binding Sites; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D012680:Sensitivity and Specificity; D014357:Trypsin / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D014361:Trypsin Inhibitors; D014357:Trypsin