Abstract
The mechanism of the enzymic isomerization and epimerization of D-erythrose 4-phosphate (Ery4P) by an enzyme preparation from bovine liver was investigated with the use of 2H2O. The incorporation of 2H was quantitatively determined by a procedure using gas chromatography-mass spectrometry. About one atom of 2H was incorporated per molecule of the enzymic epimerization reaction product of Ery4P (D-threose 4-phosphate) or that of D-ribulose 5-phosphate. Computer simulation of the Ery4P isomerization reaction indicated that the 2H of 2H2O was not directly incorporated into the enzymic reaction product (D-erythrulose 4-phosphate). Instead, intramolecular transfer of hydrogen atoms had occurred.
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- Amein M., Leatherwood J. M. Mechanism of cellobiose epimerase. Biochem Biophys Res Commun. 1969 Jul 23;36(2):223–227. doi: 10.1016/0006-291x(69)90318-0. [DOI] [PubMed] [Google Scholar]
- Davis L., Lee N., Glaser L. On the mechanism of the pentose phosphate epimerases. J Biol Chem. 1972 Sep 25;247(18):5862–5866. [PubMed] [Google Scholar]
- MCDONOUGH M. W., WOOD W. A. The mechanism of pentose phosphate isomerization and epimerization studied with T2O and H2O18. J Biol Chem. 1961 May;236:1220–1224. [PubMed] [Google Scholar]
- Ohashi K., Terada T., Kohno T., Hosomi S., Mizoguchi T., Uehara K. Enzymatic isomerization and epimerization of D-erythrose 4-phosphate and its quantitative analysis by gas chromatography/mass spectrometry. Eur J Biochem. 1984 Jul 16;142(2):347–353. doi: 10.1111/j.1432-1033.1984.tb08293.x. [DOI] [PubMed] [Google Scholar]
- Pfaffenberger C. D., Szafranek J., Horning M. G., Horning E. C. Gas chromatographic determination of polyols and aldoses in human urine as polyacetates and aldononitrile polyacetates. Anal Biochem. 1975 Feb;63(2):501–512. doi: 10.1016/0003-2697(75)90374-7. [DOI] [PubMed] [Google Scholar]
- Pitkänen E. The serum polyol pattern and the urinary polyol excretion in diabetic and in uremic patients. Clin Chim Acta. 1972 Apr;38(1):221–230. doi: 10.1016/0009-8981(72)90230-6. [DOI] [PubMed] [Google Scholar]
- ROSE I. A., O'CONNELL E. L. Intramolecular hydrogen transfer in the phosphoglucose isomerase reaction. J Biol Chem. 1961 Dec;236:3086–3092. [PubMed] [Google Scholar]
- Terada T., Mukae H., Ohashi K., Hosomi S., Mizoguchi T., Uehara K. Characterization of an enzyme which catalyzes isomerization and epimerization of D-erythrose 4-phosphate. Eur J Biochem. 1985 Apr 15;148(2):345–351. doi: 10.1111/j.1432-1033.1985.tb08845.x. [DOI] [PubMed] [Google Scholar]
- Uehara K., Hosomi S. D-Erythrulose reductase from beef liver. Methods Enzymol. 1982;89(Pt 500):232–237. doi: 10.1016/s0076-6879(82)89041-1. [DOI] [PubMed] [Google Scholar]
- Wood T. Purification and properties of D-ribulose-5-phosphate 3-epimerase from calf liver. Biochim Biophys Acta. 1979 Oct 11;570(2):352–362. doi: 10.1016/0005-2744(79)90155-4. [DOI] [PubMed] [Google Scholar]