Mechanism of the reaction catalysed by cytosolic 5′-nucleotidase/phosphotransferase: formation of a phosphorylated intermediate
- 1 August 1996
- journal article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 317 (3) , 797-801
- https://doi.org/10.1042/bj3170797
Abstract
Cytosolic 5´-nucleotidase preferentially catalysing the hydrolysis of IMP, GMP and their deoxy derivatives, and endowed with phosphotransferase activity, was purified from calf thymus and its reaction mechanism was studied. In the presence of [32P]IMP, ATP and MgCl2, a covalent enzyme–phosphate intermediate was trapped by mixing with an SDS solution. Heat or acid treatment of the enzyme before incubation with radiolabelled substrate prevented formation of the intermediate. Furthermore, on the basis of studies on the kinetic parameters of the enzyme as function of pH, and of experiments on thiol oxidation and photo-oxidation, we suggest the involvement of cysteine and histidine residue(s) in the reaction mechanism.Keywords
This publication has 18 references indexed in Scilit:
- Molecular Cloning of Human Cytosolic Purine 5′-NucleotidaseBiochemical and Biophysical Research Communications, 1994
- The role of Cys12, Cys17 and Arg18 in the catalytic mechanism of low‐Mr cytosolic phosphotyrosine protein phosphataseEuropean Journal of Biochemistry, 1993
- IMP-GMP 5′-nucleotidaseComparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1993
- Cloning, expression, and catalytic mechanism of the low molecular weight phosphotyrosyl protein phosphatase from bovine heartBiochemistry, 1992
- Pig lung 5′-nucleotidase: Effect of diadenosine 5′/ 5‴-P1, P4-tetraphosphate and its related compoundsInternational Journal of Biochemistry, 1990
- A reappraisal of the subunit molecular mass of chicken liver cytosol 5′-nucleotidaseBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1988
- Phosphotransferase activity of human alkaline phosphatases and the role of enzyme Zn2+Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1987
- The purification and properties of nucleoside phosphotransferase from mucosa of chicken intestineBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1984
- A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye BindingAnalytical Biochemistry, 1976
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970