Isolation and characterization of alpha 1-acid glycoprotein from horses, and its evaluation as an acute-phase reactive protein in horses.

The study aimed to isolate and examine alpha 1-acid glycoprotein (alpha 1AG) from horse serum, and assess its potential function as an acute-phase reactive protein in horses.

Methods of Isolation and Characterization

• The researchers separated alpha 1AG from equine serum through multiple steps, including the precipitation of the protein with ammonium sulfate, anion-exchange and cation-exchange chromatographies, and gel filtration.
• The purified serum protein had a molecular weight of approximately 46,000 and composed of about 31.4% carbohydrate.
• The alpha 1AG’s isoelectric point, the pH at which the protein carries no net electrical charge, was found to be between 2.8 and 3.7 through gel isoelectric focusing.
• Immunoelectrophoresis, a lab technique used for protein separation and characterization, showed that alpha 1AG migrated to the alpha 1-globulin region, indicating its classification as an alpha 1 protein.

Evaluation of Alpha 1AG

• A lab technique known as single radial immunodiffusion was used for quantifying alpha 1AG levels in equine serum.
• In healthy young horses (foals), alpha 1AG was found to be undetectable in the serum of those less than or equal to 7 days old but was detected by the time they reached 14 days old.
• The concentration of alpha 1AG increased gradually over the first year, reaching an average adult value of 99.23 +/- 26.90 micrograms/ml.
• In pregnant mares, the alpha 1AG concentration decreased 2-3 months before giving birth, then slowly increased until the day after birth, when it briefly dropped again. Subsequently, it rose again in the weeks following the delivery, then decreased, and increased once again between 2-4 months following delivery.
• After surgeries (castration and jejunojejunostomy) in adult horses, the alpha 1AG serum concentration quickly reached peak values within 2 to 3 days and reverted to normal ranges 14 to 28 days post-surgery.
• With these findings, the researchers concluded that alpha 1AG functions as an acute-phase reactive protein in horses, changing concentration in response to physiological states and events such as growth, pregnancy, birth, and surgery.