Abstract
A sensitive direct colourimetric method has been employed to measure kinetic parameters and pH dependence of carbamyl phosphate synthetase-I, in a liver sample from a 2 1/2-month-old girl, who died from complications of a late-developing congenital hyperammonaemia. The residual activity of carbamyl phosphate synthetase-I was 25%, whereas other urea cycle enzymes were within normal range. ApparentK m for ammonium ion (0.73 mmol/L) was significantly increased (normal range 0.24–0.51).K m for bicarbonate ion was normal, whileK m for NAG showed a slight variation from normal. The pH dependence curve of the patient's enzyme was flat, as compared to two controls showing pH optima at 7.8. Radial immunodiffusion (Mancini) of the abnormal enzyme against human enzyme antiserum gave a cross-reacting material of 10–20%. The methodological approach presented can be used to characterize abnormal enzymes in cases of partial deficiency with only 100–200 mg of liver tissue.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Batshaw, M. L. Hyperammonemia.Curr. Probl. Pediatr. 14 (1984) 1–67
Briand, P., François, B., Rabier, D. and Cathelineau, L. Ornithine transcarbamylase deficiencies in human males. Kinetic and immunochemical classification.Biochim. Biophys. Acta 704 (1982) 100–106
Ceriotti, G. Optimal conditions for ornithine carbamyl transferase determination.Clin. Chim. Acta 4 (1973) 97
Cohen, P. P. The ornithine-urea cycle: biosynthesis and regulation of carbamyl phosphate synthetase I and ornithine transcarbamylase.Curr. Top. Cell. Regul. 18 (1985) 1–19
Graf, L., McIntyre, P., Hoogenraad, N., Brown, G. and Haan, E. A. A. Carbamyl phosphate synthetase deficiency with no detectable immunoreactive enzyme and no translatable mRNA.J. Inher. Metab. Dis. 7 (1984) 104–106
Gray, R. G. F., Black, J. A., Lyons, V. H. and Pollitt, R. J. Ornithine transcarbamylase deficiency. Enzyme studies on a further case and a method of diagnosis using plasma enzyme ratios.Pediatr. Res. 10 (1976) 918–923
Grillo, M. A., Pinna, G. G. and Casolo, L. Carbamyl phosphate synthetases in human liver.Int. J. Biochem. 4 (1973) 44–450
Guthoherlein, G. and Knappe, J. Structure and function of carbamyl phosphate synthetase I. Transitions between two catalytic inactive forms and the active form.Eur. J. Biochem. 7 (1968a) 119–127
Guthoherlein, G. and Knappe, J. Modified determination of citrulline.Anal. Biochem. 26 (1968b) 188–191
Hommes, F. A., Degroot, C. J., Wilmink, C. W. and Jonxis, J. H. P. Carbamyl phosphate synthetase deficiency in an infant with severe cerebral damage.Arch. Dis. Child. 44 (1969) 688–693
Levine, R.L. and Kretchmer, N. Conversion of carbamyl phosphate to hydroxyurea. An assay for carbamyl phosphate synthetase.Anal. Biochem. 42 (1971) 324–337
Lowry, O. H., Rosebrough, N. J., Farr, A. L. and Randall, R. J. Protein measurement with the Folin Phenol reagent.J. Biol. Chem. 191 (1961) 265–273
Mancini, G., Carbonara, A. O. and Hereman, J. F. Immunochemical quantification of antigens by single radial immunodiffusion.Immunochem. 2 (1965) 235–254
Pierson, D. L. A rapid colorimetric assay for carbamyl phosphate synthetase-I.J. Biochem. Biophys. Methods 3 (1980) 31–38
Pierson, D. L. and Brien, J. M. Human carbamyl phosphate synthetase-I. Stabilization, purification and partial characterization of the enzyme from human liver.J. Biol. Chem. 255 (1980) 7891–7895
Qureshi, I. A., Letarte, J. and Oullet, R. Study of enzyme defect in a case of ornithine transcarbamylase deficiency.Diabete Metab. 4 (1978) 239–242
Rubio, V., Ramponi, G. and Grisolia, S. Carbamyl phosphate synthetase-I of human liver. Purification, some properties and immunological cross reactivity with the rat liver enzyme.Biochim. Biophys. Acta 659 (1981) 150–160
Sassaman, E. A., Zartler, A. S. and Mulick, J. A. Cognitive functioning in two sisters with carbamyl phosphate synthetase-I deficiency.J. Pediatr. Psychol. 6 (1981) 171–175
Schimke, R. T. Adoptive characteristics of urea cycle enzymes in the rat.J. Biol. Chem. 237 (1962) 459–466
Shih, V. E., Jones, T. C., Levy, H. L. and Madigan, P. M. Arginase deficiency inMacaca fascicularis. I. Arginase activity and arginine concentration in the liver and erythrocytes.Pediatr. Res. 6 (1972) 548–551
Takahara, K. and Natelson, S. Argininosuccinate acid lyase in human erythrocytes and plasma in health and disease.Am. J. Clin. Pathol. 47 (1967) 693–699
Van der Heiden, C., Desplanque, J. and Bakker, H. D. Some kinetic properties of liver ornithine carbamyl transferase (OCT) in a patient with OCT deficiency.Clin. Chim. Acta 80 (1977) 519–527
Walser, M. Urea cycle disorders and other hereditary hyperammonemic syndromes. In Stanbury, J. B., Wyngaarden, J. B., Frederickson, D. S., Goldstein, J. L. and Brown, M. S. (eds.)The Metabolic Basis of Inherited Disease, 5th edn. McGraw Hill, New York, 1983, pp. 402–438
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Qureshi, I.A., Letarte, J., Ouellet, R. et al. Kinetic abnormalities of carbamyl phosphate synthetase-I in a case of congenital hyperammonaemia. J Inherit Metab Dis 9, 253–260 (1986). https://doi.org/10.1007/BF01799657
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01799657