- Polysaccharides are macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages.
- Some polysaccharides serve as storage material, hydrolyzed as needed to provide sugar for cells.
- Other polysaccharides serve as building material for structures that protect the cell or the whole organism.
- The architecture and function of a polysaccharide are determined by its sugar monomers and by the positions of its glycosidic linkages.
Phosphoglyceratemutase (PGAM) activity inpromastigotes
of theprotozoanparasiteLeishmaniamexicanais foundonly
in the cytosol. It corresponds to a cofactor-independent
PGAM as it is not stimulated by 2,3-bisphosphoglycerate
and is susceptible to EDTA and resistant to vanadate.
We have cloned and sequenced the gene and developed a
convenient bacterial expression system and a high-yield
purification protocol. Kinetic properties of the bacterially
produced protein have been determined (3-phosphoglycer-ate:Km¼0.27 ± 0.02 mM, kcat ¼434 ± 54 s
; 2-phos-phoglycerate:Km¼0.11 ± 0.
The synthesis of ATP in the human parasiteEntamoeba histolyticais car-ried out solely by the glycolytic pathway. Little kinetic and structural infor-mation is available for most of the pathway enzymes.