Biomaterial Database

Standardized automated assay for functional alpha 1-antitrypsin. 1984

R E Mullins, and R L Miller, and R L Hunter, and B Bennett

We describe an enzymic assay for the functional activity of alpha 1-antitrypsin, in which tosyl-Gly-Pro-Lys-p-nitroanilide acetate (Chromozym PL) is the trypsin substrate. For the indicating reaction, the concentration of substrate is about double the Km of its reaction with trypsin. This assay is an improvement over reactions involving N-alpha-benzoyl-DL-arginine p-nitroanilide as substrate, the solubility of which in water is less than the Km of its reaction with trypsin. The assay is standardized in terms of active sites of trypsin inhibited per liter of serum, with p-nitrophenyl-p'-guanidinobenzoate as the active site titrant. The results agreed well with those by an immunonephelometric assay for alpha 1-antitrypsin (r = 0.953). The within-run and run-to-run precision was approximately 3%. The results of the assay varied linearly with alpha 1-antitrypsin concentration from 0 to 60 mumol/L of serum. The minimum sample size was 50 microL, and analysis of 24 samples took less than 20 min.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009391	Nephelometry and Turbidimetry	Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.	Turbidimetry,Nephelometry,Turbidimetry and Nephelometry
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D002498	Centrifugation	Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D002863	Chromogenic Compounds	Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).	Chromogenic Compound,Chromogenic Substrate,Chromogenic Substrates,Compound, Chromogenic,Compounds, Chromogenic,Substrate, Chromogenic,Substrates, Chromogenic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000515	alpha 1-Antitrypsin	Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.	Trypsin Inhibitor, alpha 1-Antitrypsin,alpha 1-Protease Inhibitor,alpha 1-Proteinase Inhibitor,A1PI,Prolastin,Serpin A1,Zemaira,alpha 1 Antiprotease,alpha 1-Antiproteinase,1-Antiproteinase, alpha,Antiprotease, alpha 1,Inhibitor, alpha 1-Protease,Inhibitor, alpha 1-Proteinase,Trypsin Inhibitor, alpha 1 Antitrypsin,alpha 1 Antiproteinase,alpha 1 Antitrypsin,alpha 1 Protease Inhibitor,alpha 1 Proteinase Inhibitor
D000814	Aniline Compounds	Compounds that include the aminobenzene structure.	Phenylamine,Phenylamines,Anilines,Compounds, Aniline
D001322	Autoanalysis	Method of analyzing chemicals using automation.	Autoanalyses
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.