Purification and characterization of rat plasma alpha-1-antitrypsin.
alpha-1-Antitrypsin was purified from rat plasma using affinity chromatography on Cibacron Blue-agarose, ion-exchange chromatography on DE-52 (pH 8.5 and 6.0) and gel filtration on Sephadex G-150. The final preparation was homogeneous as judged by polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate, by immunoelectrophoresis and by analytical ultracentrifugation. It was composed of a single polypeptide chain whose molecular weight was estimated to be about 50,000 by sedimentation equilibrium analysis. Rat alpha-1-antitrypsin was shown to be a glycoprotein containing 3.3% glucosamine, 1.7% mannose, 1.0% galactose, and 4.2% sialic acid. The interaction of rat alpha-antitrypsin with bovine beta-trypsin was studied by protease activity assays and by gel electrophoresis in sodium dodecyl sulfate. Rat alpha-1-antitrypsin inhibited bovine beta-trypsin by forming a stable equimolar complex concomitant with the release of a peptide with a molecular weight of approx. 8,000.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002417:Cattle; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006023:Glycoproteins / Q000302:isolation & purification; D007122:Immunoelectrophoresis; D007700:Kinetics; D008970:Molecular Weight; D011487:Protein Conformation; D051381:Rats; D014357:Trypsin / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000302:isolation & purification* / Q000494:pharmacology
D000596:Amino Acids; D002241:Carbohydrates; D006023:Glycoproteins; D000515:alpha 1-Antitrypsin; D014357:Trypsin