Entamoeba Histolytica: Biochemical Characterization of a Protein Disulfide Isomerase

Proper formation of oxidation and disulfide bonds is an important biochemical modification of many proteins. Early observations indicate that the formation of disulfide bonds in vivo is much faster than in vitro suggesting the presence of a catalyst for protein oxidative folding in living cells [1]. Protein disulfide isomerase (PDI, EC 3.4.1) is a eukaryotic oxidoreductase that catalyzes the oxidation, reduction and isomerization of disulfide bonds of nascent polypeptides [2]. Intracellular localization and its function have shown that PDI plays an important role in the folding of proteins carried in the secretory pathway [3].

Abstract: Amebiasis caused by gastrointestinal parasite Entamoeba histolytica results in outcome of various diseases. Studying the genome and evolution of this fascinating parasite helps to understand the basis of its pathogenicity and to explain why, when, and how it causes disease. In this review, we summarize existing knowledge about E. histolytic genomics and discuss the relationship between parasitic phenotypes and their different pathogenic behaviors. It also explains how genetic diversity reveals parasite population structure. Problems related to its evolution and demographic structure are also emphasized and need to be addressed. This considerable amount of genomic data enhances our knowledge of this pathogenic E. histolytica.

500 million people worldwide are infected with ameba. However, most infections are caused by the nonpathogenic species Entamoeba dispar, not the invasive organism Entamoeba histolytica. In the United States, most cases of amebiasis have been imported into Mexican immigrants and are being diagnosed. Bowel diseases usually manifest as dysentery, with bloody diarrhea, abdominal pain and urgency. Diagnosis depends on proof of the form of trophozoites in feces. E. Historic-specific antigen detection assays are commercially available. Endoscopic examination reveals hemorrhagic colitis and may indicate typical flask-like ulcers