Isolation and some properties of a new enzyme-binding protein in rat plasma.
alpha-1-Inhibitor3 (alpha-I3), a new enzyme-binding protein, was isolated from rat plasma by a combination of ammonium sulfate precipitation, ion exchange chromatography on DEAE cellulose and gel filtration on ultrogel AcA34. Agarose gel electrophoresis of the purified inhibitor showed a single protein band with alpha1-mobility giving a single precipitation line on immunoelectrophoresis against anti-rat serum. A specific antiserum against the purified inhibitor was raised in rabbits. alpha1-I3 showed immunologic cross-reaction with human inter-alpha-trypsin inhibitor. alpha1-I3 formed a complex with trypsin, which was thereby inhibited; the electrophoretic mobility of the complex was less than that of free inhibitor. Inflammation, induced by turpentine, caused a decrease in the serum concentration of alpha1-I3 to 36% of the initial value within 48 h. alpha2 acute phase macroglobulin (alpha2-AP) showed a simultaneous increase to 7.1 g/l and alpha1-antitrypsin (alpha1-AT) to twice its normal value.
D000510:Alpha-Globulins / Q000276:immunology / Q000302:isolation & purification*; D000818:Animals; D002352:Carrier Proteins / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007123:Immunoelectrophoresis, Two-Dimensional; D007249:Inflammation / Q000097:blood; D010447:Peptide Hydrolases / Q000097:blood; D011480:Protease Inhibitors / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D011485:Protein Binding; D051381:Rats; D014357:Trypsin / Q000097:blood
D000510:Alpha-Globulins; D002352:Carrier Proteins; D011480:Protease Inhibitors; D010447:Peptide Hydrolases; D014357:Trypsin