The homology between the serum proteins PO2 in pig, Xk in horse and alpha 1B-glycoprotein in human.

This research article explores the homological relationship between specific serum proteins in pigs (PO2 protein), horses (Xk protein), and humans (alpha 1B-glycoprotein). The study found that pig PO2 and horse Xk proteins are homologous to the human alpha 1B-glycoprotein.

Purification of Pig Po2 and Horse Xk Proteins

• The serum proteins PO2 from pigs and Xk from horses were purified using a technique called Fast Protein Liquid Chromatography (FPLC). This method is used to separate proteins and other biomolecules from a complex mixture.
• Following this, the proteins were further purified using a process that includes non-denaturing 2D agarose-PAGE (Polyacrylamide Gel Electrophoresis). This method separates proteins based on their molecular weight and electric charge, while maintaining their native structure.
• The final stage of purification involved 2D IPG-PAGE (Isoelectric Focusing-Polyacrylamide Gel Electrophoresis) which separates proteins according to their isoelectric point, that is, the pH at which a particular molecule carries no net electrical charge.

Analysis of the Separated Protein Fractions

• The purified protein fractions were then transferred to poly(4-vinyl-N-methylpyridinium iodide) coated GF/C glass fiber sheets. This step is called electroblotting and it is used to transfer the proteins onto a solid support for further analysis.
• The researchers determined the partial amino acid sequences and compositions of different genetic variants of the PO2 and Xk proteins. This was done to identify and catalogue the unique structure of each protein variant.

Homology to Human alpha 1B-glycoprotein

• The resulting comparative analysis of the amino acid sequences established that the PO2 protein from pigs, and the Xk protein from horses, share significant similarities with the alpha 1B-glycoprotein found in human serum.
• These findings suggest that these serum proteins, previously identified as polymorphic post-albumins in pigs and horses, are homologous to the human alpha 1B-glycoprotein. Polymorphic post-albumins are proteins that display a varying structure across different individual organisms of the same species.
• The study thus provided a deeper understanding of the homology or similarity in the protein structures across different species, which is fundamental in the field of evolutionary biology and can also provide valuable insights into understanding disease mechanisms and potential treatments.