Characterisation of the alpha 1-protease inhibitor system in Thoroughbred horse plasma by horizontal two-dimensional (ISO-DALT) electrophoresis. 1. Protein staining.

This research determines the characteristics of major components of eight Thoroughbred protease inhibitor (Pi) types, in particular their isoelectric points and molecular weights, using polyacrylamide gel isoelectric focusing and polyacrylamide gel pore gradient electrophoresis respectively. Contrary to previous research, it suggests that there are not two closely linked alpha 1 Pi systems based on molecular weight differences.

Major Points in the Study

• The study investigates the alpha 1-protease inhibitor system in Thoroughbred horse plasma using a method of electrophoresis called ISO-DALT.
• It focuses on the isoelectric points and the molecular weights of the major components of the eight Thoroughbred protease inhibitor types. These major components are found to focus in the range pH 3.74-4.43 and have molecular weights between 55 000-72 000 daltons.
• According to the findings, none of the homozygous Pi types are identical except for the types S1 and S2, which display partial identity.

Interpretation of Findings

• The data from this study does not support a previous contention by Juneja and colleagues (1979) that there are two closely linked alpha 1 Pi systems based on molecular weight differences.
• Considering the implications of these results, the researchers suggest that the traditional nomenclature proposed by Braend in 1970 should continue to be used to describe the eight protease inhibitor (Pi) alleles in Thoroughbred horse plasma.

Advantages of the ISO-DALT Method

• The ISO-DALT method of electrophoresis used in this study is highlighted as a superior technique for analyzing the horse protease inhibitor (Pi) system. The researchers attribute this advantage to its sensitivity compared to other existing techniques.