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Guanosine triphosphate catabolism in purine nucleoside phosphorylase deficient human B lymphoblastoid cells
Author(s) -
Barankiewicz J.,
Stein L.D.,
Cohen A.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)80170-2
Subject(s) - purine nucleoside phosphorylase , guanosine , biochemistry , gtp' , nucleoside , chemistry , catabolism , purine , hypoxanthine , inosine , lymphoblast , biology , adenosine , metabolism , cell culture , enzyme , genetics
GTP catabolism induced by sodium azide or deoxyglucose was studied in purine nucleoside phosphorylase (PNP) deficient human B lymphoblastoid cells. In PNP deficient cells, as in control cells, guanylate was both dephosphorylated and deaminated but dephosphorylation was the major pathway. Only nucleosides were excreted during GTP catabolism by PNP deficient cells and the main product was guanosine. The level of nucleoside excretion was largely affected by intracellular orthophosphate (P i ) level. In contrast, normal cells excreted nucleosides only at low P i level while at high P i levels, purine bases (guanine and hypoxanthine) were exclusively excreted. PNP deficiency had no effect on the extent of GMP deamination.