Neuraminidase activity in acanthamoeba species trophozoites and cysts.
Acanthamoeba species, a widely distributed group of free-living amoeba, can infect humans and spread hematogenously after direct interaction with the mucosal surfaces. The mechanism underlying Acanthamoeba damage to the target cell is unknown. The authors report that trophozoites and cysts of Acanthamoeba species exhibit a neuraminidase activity that is membrane associated and released into the culture medium at the start of the logarithmic phase of growth. The enzyme activity is optimal at pH 5 and at 25-30 degrees C. Live parasites release sialic acid from human cells. Therefore, the neuraminidase of Acanthamoeba species could be relevant in the colonization and damage of the sialic acid-rich corneal epithelium and in the alterations of glycolipids associated with meningoencephalitis.
Division of Geographic Medicine and Infectious Diseases, New England Medical Center Hospitals, Tufts University School of Medicine, Boston, Massachusetts.
J L
JL
Pellegrin
E
E
Ortega-Barria
M
M
Barza
J
J
Baum
M E
ME
Pereira
D000048:Acanthamoeba / Q000201:enzymology* / Q000254:growth & development; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D003470:Culture Media; D004795:Enzyme Stability; D005470:Fluorometry; D009439:Neuraminidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
D003470:Culture Media; D009439:Neuraminidase