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The acid phosphatase positive organelles of the Giardia lamblia trophozoite contain a membrane bound cathepsin C activity.
- Source :
-
Biology of the cell [Biol Cell] 2003 Mar-Apr; Vol. 95 (2), pp. 99-105. - Publication Year :
- 2003
-
Abstract
- We found a dipeptidyl aminopeptidase activity in the parasitic protozoan Giardia lamblia with properties similar to the lysosomal cathepsin C of rat-liver lysosomes. Subcellular fractionation of this parasite indicated that the cathepsin C activity is located in organelles not distinguishable from the ones containing acid phosphatase, a known marker enzyme of Giardia lysosome-like peripheral vesicles. Contrary to the rat lysosomal enzyme, Giardia cathepsin C behaved like a membrane protein. Moreover, the enzyme was not solubilized by Triton X-100 or Triton X-100/SDS at 0 degrees C but could be substantially solubilized by octylglucoside, Triton X-100 at 37 degrees C or by a pretreatment with the cholesterol complexing agent beta-cyclodextrin before the Triton/SDS treatment carried out at 0 degrees C. These observations suggest that binding/anchorage of this enzyme to membranes occurs in cholesterol-rich microdomains.
- Subjects :
- Animals
Biomarkers analysis
Cathepsin C analysis
Cholesterol
Cyclodextrins
Lysosomes chemistry
Lysosomes enzymology
Membrane Microdomains chemistry
Membrane Proteins analysis
Octoxynol
Organelles enzymology
Subcellular Fractions chemistry
Acid Phosphatase analysis
Cathepsin C metabolism
Giardia lamblia ultrastructure
Membrane Proteins metabolism
Organelles chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0248-4900
- Volume :
- 95
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Biology of the cell
- Publication Type :
- Academic Journal
- Accession number :
- 12799065
- Full Text :
- https://doi.org/10.1016/s0248-4900(03)00006-6