Studies of Mutant Human Adenylosuccinate Lyase

  • Bruce A. Barshop
  • Arthur S. Alberts
  • Paul K. Laikind
  • Harry E. Gruber
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 253A)


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 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.


Structural Mutation Purine Base Ehrlich Ascites Tumor Cell Mutant Cell Line Purine Synthesis 


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  1. 1.
    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).Google Scholar
  2. 2.
    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).Google Scholar
  3. 3.
    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).Google Scholar
  4. 4.
    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).PubMedCrossRefGoogle Scholar
  5. 5.
    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).PubMedGoogle Scholar
  6. 6.
    Suelter, C., “A Practical Guide to Enzymology,” Wiley & Sons, New York, pp. 279–280 (1985).Google Scholar
  7. 7.
    Hershfield, M.S. and Seegmiller, J.S., Regulation of de novo purine synthesis inhuman lymphoblasts, J. Biol. Chem. 252: 6002–6010 (1977).PubMedGoogle Scholar
  8. 8.
    Carter, C.E. and Cohen, L.H., The preparation and properties of adenylosuccinase and adenylosuccinic acid, J. Biol. Chem. 222: 17–30 (1956).PubMedGoogle Scholar
  9. 9.
    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).PubMedGoogle Scholar
  10. 10.
    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).CrossRefGoogle Scholar
  11. 11.
    Schultz, V., Lowenstein, J.M., Purine nucleotide cycle: evidence for the occurence of the cycle in brain, J. Biol. Chem. 251: 485–492 (1976).PubMedGoogle Scholar
  12. 12.
    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).PubMedGoogle Scholar
  13. 13.
    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).PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • Bruce A. Barshop
    • 1
  • Arthur S. Alberts
    • 2
  • Paul K. Laikind
    • 2
  • Harry E. Gruber
    • 2
  1. 1.Department of PediatricsUniversity of California San DiegoLa JollaUSA
  2. 2.Department of MedicineUniversity of California San DiegoLa JollaUSA

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