Functional identification of alpha 1-giardin as an annexin of Giardia lamblia

FEMS Microbiol Lett. 1999 Apr 1;173(1):147-53. doi: 10.1111/j.1574-6968.1999.tb13496.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Annexins / chemistry
  • Annexins / metabolism*
  • Calcium / metabolism
  • Chromatography, Gel
  • Cytoskeletal Proteins / chemistry*
  • Cytoskeletal Proteins / isolation & purification
  • Cytoskeletal Proteins / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Giardia lamblia / chemistry*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Phospholipids / metabolism
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / isolation & purification
  • Protozoan Proteins / metabolism*
  • Sequence Alignment


  • Annexins
  • Cytoskeletal Proteins
  • Phospholipids
  • Protozoan Proteins
  • giardin protein, Giardia lamblia
  • Calcium