Functional identification of alpha 1-giardin as an annexin of Giardia lamblia.
A protein with a relative molecular mass of 31 kDa was specifically extracted by EGTA from a detergent-insoluble fraction of Giardia lamblia. N-terminal sequencing showed this protein to be identical to alpha 1-giardin, a component of the ventral disc which, based on its predicted amino acid sequence, has been classified as annexin XIX. Purified alpha 1-giardin associated with multilamellar phosphatidyl serine-containing vesicles in a Ca(2+)-dependent manner, confirming that it is a functional annexin. Molecular modelling of the amino acid sequence of the giardial annexin into the X-ray structure of annexin V suggests that the Ca(2+)-binding sites, which, as in other annexins, are all located on the convex surface of the molecule, are of the low-affinity type III.
Bauer
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B
Department of Biology/Chemistry, Microbiology, University of Osnabrueck, Germany.
Engelbrecht
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S
Bakker-Grunwald
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T
Scholze
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H
D000595:Amino Acid Sequence; D000818:Animals; D017302:Annexins / Q000737:chemistry / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002850:Chromatography, Gel; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D016829:Giardia lamblia / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment
D017302:Annexins; D003598:Cytoskeletal Proteins; D010743:Phospholipids; D015800:Protozoan Proteins; C038207:giardin protein, Giardia lamblia; D002118:Calcium