Abstract
The kinetic characteristics of galactose-l-phosphate uridyl transferase have been determined in homogenates of human liver biopsies obtained from control subjects and in 50-fold purified enzyme preparations from liver obtained at autopsy. A standardized assay procedure employing linear kinetics was used to assess the enzyme activity in homogenates of liver biopsy specimens from five control subjects and four patients with congential galactosemia with demonstrated absence of the enzyme activity in red blood cells. Activity of control specimens ranged from 11.8 to 17.2 mμmoles of UDPgalactose formed per min mg of protein. Liver of two galactosemic patients, both Caucasian, possessed no detectable enzyme activity (less than 1-2% of normal). The tissue of two others, both Negro, who are known to be capable of metabolizing intravenously administered galactose, contained easily detectable enzyme at approximately 10% of the controls. No alternate enzymatic activity for formation of UDPgalactose was found in the liver of Negroes with galactosemia that was as active as the residual galactose-l-phosphate uridyl transferase. The data suggest that the residual liver enzyme activity accounts for the ability of Negroes with galactosemia to metabolize limited but significantly large quantities of galactose.
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Selected References
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- ANDERSON E. P., ISSELBACHER K. J., KALCKAR H. M. Defect in uptake of galactose-1-phosphate into liver nucleotides in congenital galactosemia. Science. 1957 Jan 18;125(3238):113–114. doi: 10.1126/science.125.3238.113. [DOI] [PubMed] [Google Scholar]
- Abraham H. D., Howell R. R. Human hepatic uridine diphosphate galactose pyrophosphorylase. Its characterization and activity during development. J Biol Chem. 1969 Feb 25;244(4):545–550. [PubMed] [Google Scholar]
- Bertoli D., Segal S. Developmental aspects and some characteristics of mammalian galactose 1-phosphate uridyltransferase. J Biol Chem. 1966 Sep 10;241(17):4023–4029. [PubMed] [Google Scholar]
- Beutler E., Baluda M. C., Halasz A. Biochemical properties of human red cell galactose-1-phosphate uridyl transferase (UDP glucose: alpha-D-galactose-1-phosphate uridyltransferase E.C.2.7.7.12) from normal and mutant subjects. J Lab Clin Med. 1966 Jun;67(6):947–954. [PubMed] [Google Scholar]
- Hsia D. Y. Clinical variants of galactosemia. Metabolism. 1967 May;16(5):419–437. doi: 10.1016/0026-0495(67)90133-3. [DOI] [PubMed] [Google Scholar]
- ISSELBACHER K. J. Evidence for accessory pathway of galactose metabolism in mammalian liver. Science. 1957 Oct 4;126(3275):652–654. doi: 10.1126/science.126.3275.652-a. [DOI] [PubMed] [Google Scholar]
- KALCKAR H. M., ANDERSON E. P., ISSELBACHER K. J. Galactosemia, a congenital defect in a nucleotide transferase. Biochim Biophys Acta. 1956 Apr;20(1):262–268. doi: 10.1016/0006-3002(56)90285-2. [DOI] [PubMed] [Google Scholar]
- Knop J. K., Hansen R. G. Uridine diphosphate glucose pyrophosphorylase. IV. Crystallization and properties of the enzyme from human liver. J Biol Chem. 1970 May 25;245(10):2499–2504. [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Rogers S., Holtzapple P. G., Mellman W. J., Segal S. Characteristics of galactose-1-phosphate uridyl transferase in intestinal mucosa of normal and galactosemic humans. Metabolism. 1970 Sep;19(9):701–708. doi: 10.1016/0026-0495(70)90067-3. [DOI] [PubMed] [Google Scholar]
- SEGAL S., BLAIR A., ROTH H. THE METABOLISM OF GALACTOSE BY PATIENTS WITH CONGENITAL GALACTOSEMIA. Am J Med. 1965 Jan;38:62–70. doi: 10.1016/0002-9343(65)90160-9. [DOI] [PubMed] [Google Scholar]
- Segal S., Blair A. SOME OBSERVATIONS ON THE METABOLISM OF D-GALACTOSE IN NORMAL MAN. J Clin Invest. 1961 Nov;40(11):2016–2025. doi: 10.1172/JCI104428. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TOPPER Y. J., LASTER L., SEGAL S. Galactose metabolism: phenotypic differences among tissues of a patient with congenital galactosaemia. Nature. 1962 Dec 8;196:1006–1006. doi: 10.1038/1961006a0. [DOI] [PubMed] [Google Scholar]