title: Pyrimidine nucleotidases from human erythrocyte possess phosphotransferase activities specific for pyrimidine nucleotides.
abstract: Two cytoplasmic forms of pyrimidine nucleotidase (PN-I and PN-II) have been purified from human erythrocytes to apparent homogeneity and partially characterized. They preferentially hydrolyse pyrimidine 5'-monophosphates and 3'-monophosphates respectively. PN-I and PN-II operate as interconverting activities, capable of transferring the phosphate from the pyrimidine nucleoside monophosphate donor(s) to various nucleoside acceptors, including important drugs like 3'-azido-3'-deoxy-thymidine (AZT), cytosine-beta-D-arabinofuranoside (AraC) and 5-fluoro-2'-deoxy-uridine (5FdUrd), pyrimidine analogues widely used in chemotherapy. Kinetic analysis showed linear behaviour for both PN-I and PN-II. PN-I phosphotransferase activity revealed higher affinity for oxynucleosides with respect to deoxy-nucleosides, whereas the contrary seems to be true for PN-II. These results show for the first time that soluble pyrimidine nucleotidases are endowed with pyrimidine-specific phosphotransferase activity.
authors.affiliation: Istituto di Biochimica, Facoltà di Medicina e Chirurgia, Università di Ancona, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Amici
authors.forename: M
authors.initials: M
authors.lastname: Emanuelli
authors.forename: G
authors.initials: G
authors.lastname: Magni
authors.forename: N
authors.initials: N
authors.lastname: Raffaelli
authors.forename: S
authors.initials: S
authors.lastname: Ruggieri
mesh_terms: D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D009708:Nucleotidases / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism*; D011743:Pyrimidines / Q000378:metabolism
chemical_list: D011743:Pyrimidines; D010770:Phosphotransferases; D009708:Nucleotidases; C030986:pyrimidine