Activity of adenosine deaminase and purine nucleoside phosphorylase in erythrocytes and lymphocytes of man, horse and cattle

The individual activities for adenosine kinase, deoxyadenosine kinase, adenosine deaminase, deoxyguanosine kinase, and purine nucleoside phosphorylase were determined during days 7 to 13 of mouse embryonic development. Adenosine deaminase increased 74-fold between days 7 and 9; deoxyadenosine kinase increased 5.4-fold during the same interval. Adenosine kinase, deoxyguanosine kinase, and purine nucleoside phosphorylase exhibited less than 2-fold changes in activity between days 7 and 13. Using Michaelis constants for each enzyme and the maximal velocities determined from enzyme assay, the relative routes of adenosine and deoxyadenosine metabolism via phosphorylation or deamination were modeled as a function of nucleoside concentration for days 7 through 13. For days 7 and 8, phosphorylation of adenosine is the principle route of metabolism at physiological concentrations. A switch occurred at day 9 and following where deamination is at least 5-fold greater than phosphorylation at all substrate concentrations. Deoxyadenosine phosphorylation was at most 10% of deamination at day 7 and then declined to less than 1% for days 9 to 13. Phosphorolysis was the principle route of deoxyguanosine metabolism through the 7 to 13 day period. Thus catabolism rather than phosphorylation was the principle pathway for purine deoxynucleoside metabolism during this period.Key words: mouse embryo, purine nucleoside metabolism.

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Purine Metabolic Enzymes in Lymphocytes: I. Adenosine Deaminase and Purine Nucleoside Phosphorylase Activities in Mouse Lymphocyte Subpopulations

Microbiology and Immunology ◽

10.1111/j.1348-0421.1982.tb00155.x ◽

1982 ◽

Vol 26 (1) ◽

pp. 77-85 ◽

Cited By ~ 6

Author(s):

Satonori Kurashige ◽

Yuki Akuzawa ◽

Toshiharu Yoshida ◽

Chisato Teshima ◽

Susumu Mitsuhashi

Keyword(s):

Adenosine Deaminase ◽

Purine Nucleoside Phosphorylase ◽

Metabolic Enzymes ◽

Lymphocyte Subpopulations ◽

Purine Nucleoside ◽

Nucleoside Phosphorylase ◽

Mouse Lymphocyte

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Human purine nucleoside phosphorylase and adenosine deaminase: gene transfer into cultured cells and murine hematopoietic stem cells by using recombinant amphotropic retroviruses.

Molecular and Cellular Biology ◽

10.1128/mcb.7.2.838 ◽

1987 ◽

Vol 7 (2) ◽

pp. 838-846 ◽

Cited By ~ 44

Author(s):

R S McIvor ◽

M J Johnson ◽

A D Miller ◽

S Pitts ◽

S R Williams ◽

...

Keyword(s):

Stem Cells ◽

Hematopoietic Stem Cells ◽

Adenosine Deaminase ◽

Base Pair ◽

Purine Nucleoside Phosphorylase ◽

Regulatory Elements ◽

Purine Nucleoside ◽

Northern Analysis ◽

Hematopoietic Stem ◽

Nucleoside Phosphorylase

Cell lines were established which produced high titers (approximately 10(6) infectious units per ml) of amphotropic, replication-defective recombinant retroviruses which transduced sequences encoding either human purine nucleoside phosphorylase (PNP) or adenosine deaminase (ADA). These viruses also contained a human hypoxanthine phosphoribosyltransferase gene as a selectable marker and a mouse metallothionein promoter (MMP) sequence just upstream from the PNP or ADA genes. Virus structure was maintained through the replication cycle if a short (216-base pair) MMP sequence was used. However, the use of a longer (1,834-base pair) MMP sequence resulted in the deletion of a significant portion of the recombinant virus genome, including the transcriptional regulatory elements of the MMP sequence. Northern analysis indicated a predominance of genome length transcripts in cells infected with deleted virus. The demonstration of substantial human PNP or ADA activity in virus-infected mouse fibroblasts by isozyme analysis suggested that active gene product was translated from either spliced or bicistronic message. The deleted ADA and PNP viruses were introduced into mouse hematopoietic stem cells by cocultivating freshly explanted bone marrow with virus producer cells. The infected marrow cells were injected into irradiated, syngeneic recipient mice, and the presence of integrated ADA or PNP proviral sequences was demonstrated in the DNA of spleen colonies by Southern analysis. Failure of these integrated proviral sequences to express active, human isozyme in spleen colony tissue indicated the existence of some regulatory constraint not active in cultured mouse cells.

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