title: Occurrence of inosine kinase as a distinct enzyme in Spirulina platensis.
abstract: Among a series of purine nucleosides, inosine was found to be phosphorylated at the highest rate by crude extracts of the cyanobacterium Spirulina platensis. The inosine phosphorylating activity could be separated from hypoxanthine-guanine phosphoribosyl transferase. This result shows that IMP formation may occur via the direct phosphorylation of inosine at its 5'-position, rather than via inosine phosphorolysis, followed by hypoxanthine phosphoribosylation, and provides unequivocal evidence for the occurrence of inosine kinase in nature.
authors.affiliation: Dipartimento di Fisiologia e Biochimica, Università di Pisa, Italy.
authors.forename: P L
authors.initials: PL
authors.lastname: Ipata
authors.forename: C
authors.initials: C
authors.lastname: Gualerzi
authors.forename: C
authors.initials: C
authors.lastname: Scolozzi
authors.forename: M G
authors.initials: MG
authors.lastname: Tozzi
authors.forename: M
authors.initials: M
authors.lastname: Trinei
authors.forename: D
authors.initials: D
authors.lastname: Barsacchi
mesh_terms: D000458:Cyanobacteria / Q000201:enzymology*; D004586:Electrophoresis; D007291:Inosine Monophosphate / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000378:metabolism*; D011687:Purines / Q000378:metabolism
chemical_list: D011687:Purines; D007291:Inosine Monophosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C062896:inosine kinase