Immunocyctochemical localization and identification of a major Mr 95,000 protein associated with the triton-X 100 insoluble cytoskeleton of Em amoeba histolytica, 1988

The abundance and cellular distribution of a Mr 95,000 protein (95K) associated with the cytoskeleton of the human parasite, Entamoeba histolytica have been studied. Growth phase amoebae were lysed in a cytoskeleton stabilizing buffer containing 1% Triton X-100. The Triton X-100 insoluble fraction was collected following sucrose density gradient centrifugation. It was estimated by quantitative densitometry that the 95K protein comprised 4.6% of the protein. Blot affinity purified monospecific antibody to the 95K protein was used to localize the 95K protein by immunofluorescence microscopy. The 95K protein was evenly dispersed throughout the cytoplasm of non-motile cells. The 95K protein appeared to become associated with actin during liposome stimulation suggesting a possible role in the reorganization of actin filaments during phagocytosis. Since the actin cytoskeleton is essential during phagocytosis, a major step in the cytopathogenic mechanism of E. histolytica, the 95K protein may also play a functional role in E. histolytica attack on mammalian cells