Summary
We have studied the residual adenylosuccinate lyase activity in cultured lymphoblasts from a pair of siblings with infantile autism who have been previously shown to have a deficiency of the enzyme. The rates and distribution of de novo purine synthesis assessed by the utilization of radiolabeled formate by intact cells was nearly normal. We compared the steady-state kinetics and thermal stability of adenylosuccinate lyase in lysates from those cells and normal lymphoblasts. There is no evidence of inhibitory activity in the lysates of the mutant cells. The optimal pH was approximately 7.8 and was indistinguishable from that in control cells. The apparent K m in the two mutant cells lines (2.6 ± 0.5 μM) is not significantly different from normal (3.3 ± 0.8 μM), but the mutants displayed markedly decreased maximum steady-state velocities (6.7 ± 1.1 compared to 13.8 ± 0.9 nmol.mg-1min-1). Residual activities in mutant cells show decreased thermal stability (t1/2 =0.21 minutes at 60°C as compared to 2.2 minutes), suggesting that there is a structural mutation of the adenylosuccinate lyase in the mutant cells.
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References
Jaeken, J. and Van den Berghe, G., An infantile autistic syndrome characterised by the presence of succinylpurines in body fluids, Lancet 2: 1058–1061 (1984).
Jaeken, J. and Van den Berghe, G., Adenylosuccinase deficiency, in: “Purine Metabolism in Man-V”, Nyhan, W.L., Thompson, L.F., and Watts, R.W.E., eds., Advances in Experimental Medicine and Biology, 195A: 27–33, Plenum Press, New York (1985).
Laikind, P.K. Gruber, H.E, Jansen, I., Miller, L. Hoffer, M., Seegmiller, J.E., Willis, R.C. Jaeken, J., and Van den Berghe, G., Purine biosynthesis in Chinese hamster cell mutants and human fibroblasts partially deficient in adenylosuccinate lyase, in: “Purine Metabolism in Man-V,” Nyhan, W.L., Thompson, L.F., and Watts, R.W.E., eds., Advances in Experimental Medicine and Biology 195B: 363-369363–369, Plenum Press, New York (1985).
Bradford, M.M., A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding, Analytical Biochemistry 72: 248–254 (1976).
Tornheim, K., Lowenstein, J.M., The purine nucleotide cycle. III. Oscillations in metabolite concentrations during the operation of the cycle in muscle extracts. J. Biol. Chem. 247: 162–169 (1972).
Suelter, C., “A Practical Guide to Enzymology,” Wiley & Sons, New York, pp. 279–280 (1985).
Hershfield, M.S. and Seegmiller, J.S., Regulation of de novo purine synthesis inhuman lymphoblasts, J. Biol. Chem. 252: 6002–6010 (1977).
Carter, C.E. and Cohen, L.H., The preparation and properties of adenylosuccinase and adenylosuccinic acid, J. Biol. Chem. 222: 17–30 (1956).
Pinto, R.M., Faraldo, A., Fernandez, A., Canales, J., Sillero, A., Sillero, M.A.G., Adenylosuccinate lyase from Artemia embryos: purification and properties, J. Biol. Chem. 258: 12513–12519 (1983).
Brox, L.W., The cleavage of adenylosuccinate and 5-amino-4-imidazole-N-succino-carboxamide ribonucleotide by an adenylosuccinate lyase from Ehrlich ascites tumor cells, Canad. J. Biochem. 51: 1072–1076 (1973).
Schultz, V., Lowenstein, J.M., Purine nucleotide cycle: evidence for the occurence of the cycle in brain, J. Biol. Chem. 251: 485–492 (1976).
Casey, P.J., Lowenstein, J.M., Purification of adenylosuccinate lyase from rat skeletal muscle by a novel affinity column, Biochem. J. 246: 263–269 (1987).
Brand, L.M. and Lowenstein, J.M., Effect of diet on adenylosuccinase activity in various organs of rat and chicken, J. Biol. Chem. 253: 6872–6878 (1978).
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© 1989 Plenum Press, New York
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Barshop, B.A., Alberts, A.S., Laikind, P.K., Gruber, H.E. (1989). Studies of Mutant Human Adenylosuccinate Lyase. In: Mikanagi, K., Nishioka, K., Kelley, W.N. (eds) Purine and Pyrimidine Metabolism in Man VI. Advances in Experimental Medicine and Biology, vol 253A. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-5673-8_4
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DOI: https://doi.org/10.1007/978-1-4684-5673-8_4
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