Toxoplasma gondii is an intracellular parasitic protozoon which infects human and most warm-blooded animals. Almost one-third of the world's population is affected by life-threatening infection of T. gondii tachyzoites form. Slow growing, transmissible and encysted bradyzoites forms are composed after tachyzoites stage. Cellular and environmental stresses induce conversion of tachyzoites from bradyzoites and this condition is associated with Heat Shock Protein (Hsps) family. Hsp100 is a member of this protein family, and coordinates to disassemble protein aggregates with Hsp70 and Hsp40 in an ATP dependent manner. Several proteins are involved during this stage differentiation and Hsp100 may help them to be in their native soluble form to perform their function as observed in other organisms. For this purpose, Hsp100-Batul was isolated from T gondii RH strain to characterize its biochemical properties in this current study. Hsp100 proteins play a role in survival and virulence of pathogens as shown in the literature. Therefore, manipulation of protein protein interaction may perturb T. gondii infection and impair conversion to tachyzoites by inhibiting Hsp100 function. Therefore, results of this work present a potential route for vaccination or immunotherapy. (C) 2015 Elsevier Inc. All rights reserved.