Purification and identification of major soluble 40-kDa antigenic protein from Entamoeba histolytica: its application for serodiagnosis of asymptomatic amebiasis.
One of the major soluble antigenic proteins of Entamoeba histolytica was purified to homogeneity and identified on a molecular basis. Its recombinant protein was expressed in Escherichia coli as a fusion protein with Shistosoma japonicum glutathione S-transferase. Apparent molecular weight of the purified antigenic protein was estimated to be 40-kDa and molecular-based analysis indicated that the purified protein was NADP+-dependent alcohol dehydrogenase (EhADH1). The application of the purified protein for the serodiagnosis of amebiasis was evaluated using an enzyme-linked immunosorbent assay applied to sera obtained from patients with amebiasis and healthy human controls. The purified protein was well recognized by the sera from asymptomatic amebiasis humans (22/22, 100%), whereas, it was less recognized by the sera from symptomatic amebiasis patients (5/16, 31%) with amebic colitis or liver abscess. To confirm the antigenicity of EhADH1, the recombinant glutathione S-transferase-EhADH1 fusion protein was also evaluated by the enzyme-linked immunosorbent assay using the same sera. The recombinant protein was also recognized by the sera from asymptomatic amebiasis humans (14/22, 64%) and less recognized by the sera from symptomatic amebiasis patients (2/16, 13%). These results suggest that the purified protein is applicable antigen for serodiagnostic screening of asymptomatic amebiasis humans.
Sanuki
J
J
Department of Tropical Medicine and Parasitology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan.
Nakano
K
K
Tokoro
M
M
Nozaki
T
T
Okuzawa
E
E
Kobayashi
S
S
Asai
T
T
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification*; D003001:Cloning, Molecular; D004748:Entamoeba histolytica / Q000276:immunology*; D004749:Entamoebiasis / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D008101:Liver Abscess, Amebic / Q000175:diagnosis / Q000276:immunology; D008970:Molecular Weight; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000939:Epitopes; D011993:Recombinant Fusion Proteins