Protease inhibitor system in horses: classification and detection of a new allele

Abstract

A method of horizontal thin layer polyacrylamide gel electrophoresis at acid pH was developed for the separation of the prealbumins in equine plasma. Using this method, it was possible to split the S allele into 2, S1 and S2, bringing the total number of prealbumin alleles in Thoroughbred horses to 8. The gene frequencies of these 8 alleles in Australian Thoroughbreds are presented. All 8 prealbumin types exhibit antiprotease activity and the name prealbumin (Pr) should be abandoned in favor of protease inhibitor (Pi) although at this stage it is not known whether this incorporates the Pi1 and Pi2 described by Juneja, et al.