title: Antibody binding to alpha 2-macroglobulin facilitates direct quantitation of elastase-alpha 2-macroglobulin complexes by a simple ELISA technique.
abstract: In order to investigate the effect which the binding of anti-alpha 2-macroglobulin (anti-A2M) antibody has on subsequent antigen-antibody reaction between the complexed elastase and the solid phase anti-elastase antibody, elastase alpha 2-macroglobulin complex (EMC) was incubated with anti-A2M antibody and then extracted by a solid-phase bound rabbit anti-elastase antibody. A doubling dilution series of EMC generated dose related absorbance values. The critical factor permitting the immunological detection of A2M-bound elastase is the pre-incubation of anti-A2M antibody with EMC in solution. The assay exhibited a lower detection limit of 0.5 ng bound elastase per ml and EMC levels in serum samples from ten volunteers were significantly higher than in plasma (28 vs. 21 ng/ml, p < 0.05, Student's t test for paired samples). The EMC levels measured with this assay were essentially identical to those obtained when phenyl methyl sulfonyl fluoride (PMSF) was added to the assay buffer solution.
authors.affiliation: Department of Medicine, Royal Postgraduate Medical School, London, UK.
authors.forename: E O
authors.initials: EO
authors.lastname: Adeyemi
authors.forename: H J
authors.initials: HJ
authors.lastname: Hodgson
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D046911:Macromolecular Substances; D010196:Pancreatic Elastase / Q000032:analysis* / Q000097:blood / Q000276:immunology; D011485:Protein Binding; D000511:alpha-Macroglobulins / Q000032:analysis* / Q000276:immunology
chemical_list: D046911:Macromolecular Substances; D000511:alpha-Macroglobulins; D010196:Pancreatic Elastase