2-Amino-5-nitro-6-ribitylamino-4(3H)-pyrimidinone (7) was phosphorylated with chlorophosphoric acid yielding an isomer mixture containing about 63% of the 5'-phosphate 7a together with other monophosphates and bisphosphates of 7. Preparative HPLC afforded pure 7a. Catalytic hydrogenation of 7a yields the labile substrate of pyrimidine deaminase, 2,5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5'-...

A variety of metabolic intermediates of the glycolytic pathway and tricarboxylic acid cycle have been found to be inhibitors of 6-phosphogluconate dehydrogenase isolated from sheep liver. All nucleoside 5’-triphosphates and 5’diphosphates are inhibitors with Ki values averaging 0.8 mM, nucleoside 5’-monophosphates are also inhibitory with Ki values averaging 6 mu. The 2’and 3’monophosphates of ...

Cytosolic 5'(3')-deoxyribonucleotidase (cdN) and mitochondrial 5'(3')-deoxyribonucleotidase (mdN) catalyze the dephosphorylation of deoxyribonucleoside monophosphates and regulate dTTP formation in cytosol and mitochondria, protecting DNA replication from imbalanced precursor pools. They can also interfere with the phosphorylation-dependent activation of nucleoside analogues used in anticancer ...

The e (P4) phosphatase from Haemophilus influenzae functions in a vestigial NAD(+) utilization pathway by dephosphorylating nicotinamide mononucleotide to nicotinamide riboside. P4 is also the prototype of class C acid phosphatases (CCAPs), which are nonspecific 5',3'-nucleotidases localized to the bacterial outer membrane. To understand substrate recognition by P4 and other class C phosphatase...

We report the isolation and characterization of a second capping ribozyme, called 6.17. This ribozyme has substrate requirements that are very similar to a previously isolated capping ribozyme called Iso6. Both ribozymes promote capping and cap exchange reactions with a broad range of nucleotide substrates. The ribozymes mediate a reaction where the terminal phosphate of the nucleotide substrat...

The kinetic properties of highly purified human placental cytoplasmic 5'-nucleotidase were investigated. Initial velocity studies gave Michaelis constants for AMP, IMP, and CMP of 18, 30, and 2.2 microM, respectively. The enzyme shows the following relative Vmax values: CMP greater than UMP greater than dUMP greater than GMP greater than AMP greater than dCMP greater than IMP. The activity was ...

The review aimed at pooling together available information on 5'-nucleotidase – an enzyme hydrolyzing ribo- and deoxyribonucleoside-5'-monophosphates. most important product of activity is adenosine. This is, in fact, involved aspects normal physiology, along with numerous pathological processes. article discusses the role pregnancy, its involvement early post-implantation development, prolifer...

A short ischemic period induced by the transient occlusion of major brain arteries induces neuronal damage in selectively vulnerable regions of the hippocampus. Adenosine is considered to be one of the major neuroprotective substances produced in the ischemic brain. It can be released from damaged cells, but it also could be generated extracellularly from released ATP via a surface-located enzy...