Effect of isolation methods and of possible genetic factors on the multiple isoenzymic forms of pig muscle phosphoglucose isomerase

Abstract

1. 1. Pig muscle phosphoglucose isomerase has been found to exist in three isoenzymic forms. 2. 2. Procedural artifacts, such as fractionation and chromatography methods, inadvertent oxidation during preparative work-up and post-mortem aging effects prior to commencement of isolation from the muscle tissue, have been eliminated as causes for the presence of the multiple enzyme forms. 3. 3. Studies on the amino acid and peptide compositions of the individual isoenzymes yielded small, but distinct differences in primary structure. 4. 4. These findings, in conjunction with literature reports on pig breeding studies, are interpreted to suggest that genetic determinants are the primary origin of the isoenzymes with secondary, possibly nongenetic, factors being responsible for the relative distributions of the three enzyme forms.