Adenine phosphoribosyltransferase mutants

Jr., Purine mutants of mammalian cell lines III Control of purine biosynthesis in adenine phosphoribosyltransferase mutants of CHO cells. Somat. Cell Genet. 3 195-206 (1977). 

H5. Hidaka, Y., Tarle, S. A., Fujimori, S Kamatani, N Kelley, W. N., and Palella, T. D., Human adenine phosphoribosyltransferase deficiency Demonstration of a single mutant allele common to the Japanese. J. Clin. Invest. 81,945-950 (1988). 

Levine and Taylor (78) have isolated a double mutant of E. coli, blocked in the salvage pathways leading to GMP, that is extremely sensitive to exogenous adenine (78, 128). This strain was missing both hypoxanthine phosphoribosyltransferase and guanine phos-phoribosyltransferase. Two classes of adenine-resistant, second-site revertants were isolated. One class was blocked at the adenine phosphoribosyltransferase reaction and thus could not convert adenine to AMP 128). Therefore, the toxicity was mediated through AMP. The other class represented purR cells, which constitutively expressed the de novo pathway. 

J.M. Wilson, P.E. Daddona, H.A. Simmonds, K.J. Van Acker, and W.N. Kelley, Human adenine phosphoribosyltransferase immunochemical quantitation and protein blot analysis of mutant forms of the enzyme, Biol. Chem. 257 1508-1515 (1982). 

Adenine phosphoribosyltransferase activity assayed by an analogous method using 0.6 mM adenine-8-l C (specific activity 4 mCI/mmole) was not significantly altered in any of the HGPRT-deficient clones (Table II). Starch gel electrophoresis using a method only slightly modified from that of Watson et. al. (19) showed no difference in electrophoretic mobility of mutants partially deficient in HGPRT (Fig. 3) but could not be used to examine the clones with severely deficient enzyme activity. 

F. M., and SEEGMILLER, J. E. Kinetic studies of mutant human erythrocyte adenine phosphoribosyltransferases. 

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