Phosphate uptake in the yeast Candida tropicalis: purification of phosphate-binding protein and investigations about its role in phosphate uptake.
The purification of a phosphate-binding protein (PiBP2) by immunoadsorption is described. The entire anti phosphate-binding protein 2 antibodies as well as the Fab fragments obtained from these antibodies inhibit Pi uptake by whole cells. The inhibition is a mixed type of inhibition (Vm and Km are affected). These results should be regarded as a possible involvement of phosphate-binding protein 2 in Pi uptake. The binding of 125I-labelled fragments prepared from anti phosphate-binding protein 2 antibodies to whole cells, to shocked cells and to protoplasts has been investigated. The results confirm the release of phosphate-binding protein by osmotic shock and during protoplast formation. From these findings, a cell-wall localisation, near the cell surface of the phosphate-binding protein should be proposed.
D000906:Antibodies / Q000276:immunology; D000915:Antibody Affinity; D001666:Binding Sites, Antibody; D001693:Biological Transport, Active; D002175:Candida / Q000032:analysis / Q000378:metabolism*; D002352:Carrier Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D007163:Immunosorbent Techniques; D028044:Phosphate-Binding Proteins; D010710:Phosphates / Q000378:metabolism*
D000906:Antibodies; D002352:Carrier Proteins; D005656:Fungal Proteins; D028044:Phosphate-Binding Proteins; D010710:Phosphates