Abstract
The trophozoites of Giardia lamblia possess several protein antigens, predominant among them a protein of approximately 32,000 Da. In the present study, we used monospecific antibodies that recognize this protein to demonstrate its presence on a variety of G. lamblia isolates from human and animal sources. Immune electron microscopy was used to localize 32-kDa antigen on the trophozoite membrane and disk. Immunofluorescent assays employing monospecific antibodies confirmed the presence of 32-kDa antigen on the membrane and disk and its absence on flagella or nuclei. The N-terminal 17 amino acids of the 32-kDa antigen are identical to alpha-1-giardin, a protein component of microribbons on the ventral disk. These results suggest that the 32-kDa immunodominant trophozoite antigen is alpha-1-giardin.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Antibodies, Protozoan
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Antibody Specificity
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Antigens, Protozoan / genetics
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Antigens, Protozoan / immunology
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Antigens, Protozoan / isolation & purification*
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Cell Movement
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Cytoskeletal Proteins / genetics
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Cytoskeletal Proteins / immunology
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Cytoskeletal Proteins / isolation & purification*
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Fluorescent Antibody Technique
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Giardia lamblia / immunology*
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Giardia lamblia / ultrastructure
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Glycosylation
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Immunodominant Epitopes / genetics
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Immunodominant Epitopes / immunology
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Immunodominant Epitopes / isolation & purification*
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Microscopy, Immunoelectron
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Molecular Sequence Data
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Protein Processing, Post-Translational / drug effects
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Protozoan Proteins / genetics
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Protozoan Proteins / immunology
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Protozoan Proteins / isolation & purification*
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Sequence Analysis
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Tunicamycin / pharmacology
Substances
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Antibodies, Protozoan
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Antigens, Protozoan
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Cytoskeletal Proteins
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Immunodominant Epitopes
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Protozoan Proteins
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giardin protein, Giardia lamblia
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Tunicamycin