Cytosol 5′-nucleotidase from chicken liver purification and some properties

Naito, Yoshitsugu; Tsushima, Kenji

doi:10.1016/0005-2744(76)90232-1

Cited by 41 publications

(12 citation statements)

References 25 publications

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“…This would agree with the suggestion of Murray and Friedrichs (1969) about the replacement of the purine bases. Bovine brain 5'-N displayed hyperbolic kinetics with 5'-AMP, in agreement with the results reported by Fritzson (1969) for the enzyme from rat liver and by Naito and Tsushima (1976) for the enzyme from chicken liver. In contrast, van den Berghe (1977) reported sigmoidal kinetics for rat liver 5'-N.…”

Section: Discussionsupporting

confidence: 91%

“…The enzyme hydrolyses the purine and pyrimidine 5'-nucleotides; its activity on the ribonucleotides is greater than on the deoxyribonucleotides. 5'-IMP is a better substrate for bovine brain 5'-N than 5'-AMP, in accordance with the activity of the soluble rat liver 5'-N (Fritzson, 1969;van den Berghe et al, 1977) and the cytosolic 5'-N from chicken liver (Naito and Tsushima, 1976). The greater activity shown by 5'-N over 5'-IMP relative to GMP and AMP may be related to a guanine and adenine mononucleotide protection mechanism enabling these nucleotides to be phosphorylated to di-and triphosphates.…”

Section: Discussionsupporting

confidence: 72%

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Purification and Characterization of Bovine Brain 5′‐Nucleotidase

Montero¹,

Fes²

1982

Journal of Neurochemistry

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The 5'-nucleotidase located in the cytoplasmic fraction of bovine brain cortex was purified to electrophoretic homogeneity. The molecular weight was 134,000 daltons in the presence of sodium deoxycholate, whereas the enzyme formed high molecular weight aggregates in the absence of detergent. The purified enzyme showed the same kinetic and electrophoretic behaviour as the enzyme present in the original cytoplasmic fraction, and the presence of surfactants did not change the Km and Vm values. The nucleotidase from this source was a phosphohydrolase of 5'-mononucleotides acting on the deoxyribonucleotides and ribonucleotides of purines and pyrimidines. 5'-IMP was the preferred substrate; the optimum pH was 7.5. The study of the influence of the temperature on the initial reaction rates allowed calculation of the delta Ea and delta H degrees values. The variation of Vm and Km with a change in pH suggests the existence of a sulfhydryl group and an imidazole group in the enzyme-substrate complex.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 72%

Purification and Characterization of Bovine Brain 5′‐Nucleotidase

Montero¹,

Fes²

1982

Journal of Neurochemistry

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“…The erythrocyte purine 5'-nucleotidase is thus the only enzyme which has been reported hitherto to be stimulated by 2,3-DPG. The apparent Mr -of the 2,3-DPG-stimulated purine 5'-nucleotidase of human erythrocytes, namely 250000, is close to that of the cytosolic 5'-nucleotidase of chicken [26] and rat [31] liver.…”

Section: Properties Of the Erythrocyte Purine 5'-nucleotidasementioning

confidence: 64%

“…The kinetic characteristics of the purine 5'-nucleotidase isolated from human erythrocytes are in many respects similar to those of the cytosolic 5'-nucleotidases of other tissues. This includes an absolute dependency on Mg2", a pH optimum around 6.3-6.5 and a higher affinity for inosine and guanosine 5'-nucleotides than for AMP and other nucleoside monophosphates [1][2][3][4][5]26].…”

Section: Properties Of the Erythrocyte Purine 5'-nucleotidasementioning

confidence: 99%

5′-Nucleotidase activities in human erythrocytes. Identification of a purine 5′-nucleotidase stimulated by ATP and glycerate 2,3-bisphosphate

Bontemps

Berghe

Hers

1988

Biochemical Journal

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A purine 5'-nucleotidase has been separated by DEAE-Trisacryl chromatography from other 5'-nucleotidase activities present in human haemolysates and purified approx. 30,000-fold by subsequent chromatography on Blue Sepharose. The enzyme has an Mr of around 250,000, displays hyperbolic substrate-saturation kinetics and hydrolyses preferentially IMP, GMP and their deoxy counterparts. It is much less active with AMP and dAMP. The purine 5'-nucleotidase is inhibited by Pi, and is strongly stimulated by ATP, dATP and GTP, and by glycerate 2,3-bisphosphate. Stimulators decrease Km and increase Vmax. Glycerate 2,3-bisphosphate is the most potent stimulator of the enzyme and, under physiological conditions, over-rides the influence of the other effectors. Glycerate 2,3-bisphosphate also influences the binding of the enzyme to DEAE-Trisacryl, as evidenced by the different elution profile obtained with fresh as compared with outdated blood. It is concluded that the glycerate 2,3-bisphosphate-stimulated purine 5'-nucleotidase is responsible for the dephosphorylation of IMP and GMP, but not of AMP, in human erythrocytes.

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“…The delivery of ganciclovir to the hepatocytes was assumed to be uniform throughout the liver acinus because similar levels of viral protein suppression were observed from the portal tract to the central vein. Ganciclovir is probably activated by the enzyme IMP-GMP 5' nucleotidase which is abundant in avian liver cytosol (32). When ganciclovir is converted into the tri-phosphate form, it causes premature termination of viral DNAlSynthesis (10).…”

Section: Discussionmentioning

confidence: 99%

Alterations in intrahepatic expression of duck hepatitis B viral markers with ganciclovir chemotherapy

Luscombe

Pedersen

Bowden

et al. 1994

Liver

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Ducks congenitally infected with duck hepatitis B virus (DHBV) were treated with the guanosine analogue, ganciclovir, and the effect on serum and intrahepatic expression of DHBV DNA and viral proteins was examined. After 21 days of ganciclovir treatment, a substantial reduction in viraemia occurred; in contrast, the level of circulating DHBV surface antigen was unchanged. Ganciclovir therapy also substantially reduced the level of DHBV DNA replicative intermediates and the expression of viral core and surface antigen in hepatocytes. However, despite the antiviral treatment some liver cells, including the bile duct epithelial cells and putative oval cells, maintained their intense staining for the viral proteins. Furthermore, DHBV‐infected cells in extrahepatic sites such as the pancreas, kidney and spleen were also unaffected by ganciclovir treatment. These results suggest that monotherapy with nucleoside analogues is unlikely to eliminate chronic hepadnaviral infection, and antiviral programs should be designed to target all cell populations infected by the virus.

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Cytosol 5′-nucleotidase from chicken liver purification and some properties

Cited by 41 publications

References 25 publications

Purification and Characterization of Bovine Brain 5′‐Nucleotidase

Purification and Characterization of Bovine Brain 5′‐Nucleotidase

5′-Nucleotidase activities in human erythrocytes. Identification of a purine 5′-nucleotidase stimulated by ATP and glycerate 2,3-bisphosphate

Alterations in intrahepatic expression of duck hepatitis B viral markers with ganciclovir chemotherapy

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