Regulation of purine uptake in normal and neoplastic cells.

  title={Regulation of purine uptake in normal and neoplastic cells.},
  author={Mathias M. Mueller and M Kraupp and Peter Chiba and Helmut Rumpold},
  journal={Advances in enzyme regulation},
Purine bases and purine nucleosides pass the cell membrane by facilitated diffusion. For purine bases two different carrier proteins seem to exist. Purine bases are trapped intracellularly immediately after passage of the cell membrane by the action of purine phosphoribosyltransferases (PRTs). Comparison of kinetic data of transport and intracellular enzyme reactions shows that intracellular metabolism is rate limiting for the whole uptake process. Since phosphate stimulates the uptake of bases… CONTINUE READING