Alpha 2 giardin is an assemblage A-specific protein of human infectiveGiardia duodenalis

Abstract

SUMMARYOf the 7 genetic assemblages of the parasiteGiardia duodenalisonly 2 (A and B) are known to cause infections in humans. These assemblages have been characterized in detail at the genomic level but few studies have examined differences in the proteins expressed. Employing one and two-dimensional PAGE we have identified an assemblage A-specific protein of human infectiveG. duodenalis; alpha 2 giardin. The protein difference was evident using both electrophoretic techniques. Alpha 2 giardin is known to be a structural protein and associates with the caudal flagella and the plasma membrane; however, its exact function is unknown. Although several proteins unique to assemblage B were also observed, we were unable to identify these proteins due to a lack of genomic data available for assemblage B isolates. Together, these proteins represent distinct phenotypic differences between the human infective assemblages ofG. duodenalisand support the need to revise the taxonomy of this parasite.