Isolation, characterization and quantitation of canine alpha-1-acid glycoprotein

The present study was designed to investigate the physicochemical properties of canine alpha-1-acid glycoprotein (AGP), and to establish a method for measuring serum AGP in canine. Fifty-three normal beagles were used in the study. AGP was purified from normal canine sera by successive ammonium sulfate precipitation, ion-exchange chromatography and gel filtration. The serum AGP concentration was measured by single radial immunodiffusion (SRID). Canine AGP had a molecular weight of 42,000 ± 2,000 Da and contained 40.9% carbohydrate. Gel isoelectric focusing revealed microheterogeneity with 6–7 bands in a pI range (isoelectric points) of 3.2–3.8. AGP migrated to the α1-globulin region on immunoelectrophoresis. The serum AGP level of 35 normal beagles was 283.4 ± 113.3 μg/ml. Canine AGP was isolated, and its physicochemical properties were clarified. SRID may be a useful method for quantification of serum AGP in canine.