Purine base transport in normal and mutant erythrocytes

The uptake of adenine and hypoxanthine in HGPRT-deficient and normal human erythrocytes was measured using a rapid filtering centrifugation technique. The transport of hypoxanthine as well as of adenine is impaired in the mutant cells. The transport of hypoxanthine into HGPRT-deficient erythrocytes differs from that into normal cells with respect to a higher accumulation capacity, to lower initial velocities and to the kinetic properties of the translocator. In addition, a higher accumulation capacity and lower initial velocities of adenine uptake could be demonstrated in mutant cells. A linkage of the purine translocator with purine phosphoribosyltransferases associated with the erythrocyte membrane is discussed.