Loading...
  • pathways
  • From changes of total purine ribonucleotide pattern an activation period in the nucleotide metabolic pathways of liver and skeletal muscle during the proliferating phase of tumor growth is postulated. (aacrjournals.org)
  • Results obtained for non-phosphorylating and phosphorylating mitochondria, as the endogenous ubiquinone redox state was gradually varied by a lowering rate of the ubiquinone-reducing or ubiquinol-oxidizing pathways, indicate that the endogenous ubiquinone redox state has no effect on non-esterified fatty acid-induced UCP1 activity in the absence of GTP, and can only regulate this activity through sensitivity to inhibition by the purine nucleotide. (ac.be)
  • De novo pathways do not use free bases: adenine (abbreviated as A), guanine (G), cytosine (C), thymine (T), or uracil (U). The purine ring is built up one atom or a few atoms at a time and attached to ribose throughout the process. (wikipedia.org)
  • guanine
  • That two purine nucleotide synthase ribozymes share patterns in common with these naturally selected protein and RNA systems suggests that a single optimal strategy to specifically recognize guanine by hydrogen bonding and stacking interactions exists in nature. (nih.gov)
  • enzymes
  • Whether or not a nucleotide synthase ribozyme had measurable nucleobase binding affinity, all families of nucleotide synthetase ribozymes were extremely sensitive to nucleobase modification and showed surprising parallels to the substrate preferences of highly evolved protein nucleotide synthase enzymes. (nih.gov)
  • metabolic
  • ASL is important to cells not only because of its involvement in creating purines needed for cellular replication, but also because it helps regulate metabolic processes by controlling the levels of AMP and fumarate in the cell. (wikipedia.org)
  • uracil
  • For example, the family A pyrimidine nucleotide synthetase ribozyme was ~10,000 times slower with uracil than with 4-thiouracil and reactivity with 2-thiocytosine, 2-thiopyrimidine, 2-thiopyridine and 5-carboxy-2-thiouracil could not be detected (Figure 3). (nih.gov)
  • synthetase
  • The arrows point to reaction efficiencies for ribozymes with the indicated substrate molecule: red arrows indicate the MA purine nucleotide synthetase ribozyme reaction efficiencies, purple indicates the RA purine nucleotide synthetase ribozyme, blue indicates the Family A pyrimidine nucleotide synthethase ribozyme and green indicates the improved a15 ribozyme derived from the Family A ribozyme by reselection. (nih.gov)
  • As these purine nucleotide synthetase ribozymes were much slower with other purine modifications this indicates a lack of substrate discrimination at the 2-position. (nih.gov)
  • This reaction closes the ring and produces a 5-membered imidazole ring of the purine nucleus (AIR): ATP + 2-(formamido)-N1-(5-phospho-β-D-ribosyl)acetamidine ⇌ {\displaystyle \rightleftharpoons } ADP + 5-amino-1-(5-phospho-β-D-ribosyl)imidazole + phosphate + H+ AIR synthetase catalyzes the transfer of the oxygen of the formyl group to phosphate. (wikipedia.org)
  • protein
  • Effect of the msb3msb4 double mutation on the intracellular pool of purine nucleotides in the yeast Saccharomyces cerevisiae: application to the study of the biological activity of the oncogenic human protein oncTre210p. (ac.be)
  • intermediate
  • This six-step process links glycine, formate, bicarbonate, glutamine, and aspartate to lead to an intermediate that contains almost all the required atoms to synthesize a purine ring. (wikipedia.org)
  • Glutamate
  • To test the significance of the purine nucleotide cycle in renal ammoniagenesis, studies were conducted with rat kidney cortical slices using glutamate or glutamine labelled in the alpha-amino group with 15N. (biochemj.org)
  • Bovine liver glutamate dehydrogenase was found to be regulated by nucleotides in the late 1950s and early 1960s by Carl Frieden. (wikipedia.org)
  • cycle
  • ATP → ADP + Pi (Utilisation of ATP for Muscle contraction) 2 ADP → ATP + AMP (Catalysed by Adenylyl kinase/Myokinase) Purine nucleotide cycle occurs during strenuous exercise, fasting or starvation when ATP reservoirs run low. (wikipedia.org)
  • Aspartate can re-enter purine nucleotide cycle. (wikipedia.org)
  • The data obtained suggest that the contribution of the purine nucleotide cycle to ammonia formation from glutamine in rat renal tissue is insignificant. (biochemj.org)
  • Phosphocreatine stores: These stores, consumed in the purine nucleotide cycle, are vital for very high-intensity exercise of short duration, as other stores are depleted early. (medscape.com)
  • AMP is normally converted into IMP by myoadenylate deaminase-so myoadenylate deaminase deficiency reduces energy that would be available to the cell through the purine nucleotide cycle. (wikipedia.org)
  • precursor
  • For example, nucleotides are not needed in the diet as they can be constructed from small precursor molecules such as formate and aspartate. (wikipedia.org)
  • mitochondria
  • Our studies of the membranous ubiquinone reduction level in mitochondria demonstrate that activation of UCP1 leads to a purine nucleotide-sensitive decrease in the ubiquinone redox state. (ac.be)
  • atoms
  • The N K-edge XANES spectra for all of these nucleotides are classified by the numbers of N atoms with particular chemical bonding characteristics in the purine moiety. (osti.gov)
  • proteins
  • Indeed, some rich foods are high in proteins and purines and therefore may contribute to gout flare-ups, however low fat dairy products have now been shown to have a preventative effect. (gout-remedies.net)