Polyacrylamide gel electrophoresis of isoenzymes from Entamoeba species

In this preliminary report, we describe a polyacrylamide gel electrophoresis technique for the resolution of isoenzyme patterns of four isolates of Entamoeba histolytica and one isolate of Entamoeba coli. Our findings were similar to previous findings for three enzyme systems: maleic enzyme (malate dehydrogenase [EC 1.1.1.40]), hexokinase (EC 2.7.1.1), and phosphoglucomutase (EC 2.7.5.1). We found preliminary evidence that glucosephosphate isomerase (EC 5.3.1.9) may also differentiate invasive amoebae from noninvasive amoebae, when the isoenzymes are separated by polyacrylamide gel electrophoresis, whereas this differentiation is not evident with starch-gel electrophoresis. We used an Rf system to relate isoenzyme band mobility to the migration distance of a standard E. histolytica strain (HK-9). The numerical identification of isoenzyme bands can simplify the grouping of isolates into zymodemes.