Adenyl nucleotides

For luciferin, a firefly luciferase cosubstrate, another method of retention has been evaluated which consisted of incorporating the substrate in acrylic microspheres during their formation, these last being then confined in a polymeric matrix31. Using the suitable co-immobilized enzymes (adenylate kinase and creatine kinase), the three adenylic nucleotides (ATP, ADP and AMP) could be assayed continuously and reproducibly with a selfcontainment working time of 3 h. 

Active fish have a better developed capillary system in the red muscle to supply oxygen to the mitochondria, and a higher haematocrit (Blaxter et al., 1971). The red muscle tissue also contains more cytochromes (respiratory proteins), and exhibits more cytochrome oxidase activity, which is responsible for transferring electrons in die respiratory chain, more efficient respiration control (oxidative phosphorylation and P/O coefficient) and a greater Atkinson charge, which characterizes energy reserve accumulated in adenyl nucleotides ... 

There are also changes in the rates of metabolism as red blood cells appear and aerobic processes intensify (Lasker and Theilacker, 1962 Laurence, 1975 Timeyko and Novikov, 1991) during the early phases of ontogenesis. Oxygen consumption increases, as do the number of mitochondria and their protein contents (Abramova and Vasilyeva, 1973 Ozemyuk, 1993). The adenyl nucleotide pool (ATP and ADP) decreases (Milman and Yurovitsky, 1973 Boulekbache, 1981), while the activity of cytochrome oxidase increases (Ozemyuk, 1993). The increased energy metabolism corresponds to a considerable extent with motor activity (Reznichenko, 1980). In the yolk sac, the activity of proteinase, which supplies nitrogenous materials to the embryo, increases, as does the rate of amino acid incorporation into the body proteins. 

Excessive depletion of lipids, adenyl nucleotides and proteins during wintering may result in mass mortality, especially if the temperature is very low. Many workers have reported a relationship between the energy reserves at... 

Bilyk, T.I. (1989). Impact of environmental factors on the adenyl nucleotide metabolism in fish muscle and liver (In Russian). Gidrobiologicheskii Zhurnal 25, 58-65. 

The energy status of a cell can be calculated from the levels of adenylate nucleotides and is expressed as the energy or adenylate charge ... 

This activity was found first in the Neurospora crassa mutant deficient in adenine, where the concentrations of ATP and other adenyl nucleotides were sharply reduced (Kulaev and Bobyk, 1971). 

V. L. Kozel tsev, S. S. Debov and N. I. Votrin (1969). The role of inorganic polyphosphates in the formation of adenyl nucleotides in a culture of Brevibacterium ammoniagenes (in Russian). Vopr. Med. Khim., 5, 602-614. 

Adenylate kinase again. Adenylate kinase, an enzyme discussed in great detail in Chapter 9. is responsible for interconverting the adenylate nucleotide pool ... 

In support of this h5q>othesis Chen and Kim established the existence of three adenylate nucleotide sites one catalytic ATP site, one regulatory ATP site, and one regulatory site for cyclic AMP and AMP (22). 

Bochner BR, Lee PC, Wilson SW, Cutler CW, Ames BN (1984) AppppA and related adenylated nucleotides are synthesized as a consequence of oxidation stress. Cell 37 225-232... 

The interaction of adenyl nucleotides with the process of ADP-ribosylation was evaluated using a permeable cell assay system to allow cellular uptake of the substrate NAD. The system used was one in which the MCF-7 human breast cancer cells were... 

The low RBC ATP concentration is the most probable explanation for the hemolysis (1). In vitro studies of adenosine metabolism by intact patient s RBC showed as expected, a markedly decreased ATP synthesis from adenosine moreover, metabolic studies of adenylic nucleotides labelled with radioactive adenine indicate that AMP degradation (probably by hydrolysis of the phosphate ester followed by deamination of adenosine) is abnormally elevated in the patient s erythrocytes. Thus, the low RBC ATP concentration appears to be secondary to both a diminished synthesis of AMP from adenosine and an excessive catabolism of AMP. 

Lee PC, Bochner BR and Ames BN (1983b) Diadenosine-5, 5" -P P -tetraphosphate and related adenylated nucleotides in Salmonella typhimurium. J Biol Chem 258 6827-6834 Lee SY, Vedamuthu ER, Washam CJ and Reinbold GW (1969) Diacetyl production by propionibacteria. J Dairy Sci 52 893... 

Mitochondrial ATPase. When freshly prepared liver mitochondria are tested, little if any ATPase activity can be detected. However, when these mitochondrial preparations are allowed to age, a large increase in ATPase activity is consistently observed. This effect can be abolished by the early addition of one of the adenine nucleotides to the reaction mixture. It is suggested that these adenylic nucleotides may interact by maintaining or resynthesizing important cofactors in the mitochondria. Since the sudden increase in ATPase activity results from aging, it is of interest to note that an equivalent decrease in phosphorylative capacity of the mitochondria also occurs. 

Taken from Yeh and Phang (116). Erythrocytes were incubated with C-labeled precursors at a concentration of 10 fiM and the nucleotide products were separated by high-pressure liquid chromatography. Radioactivity in the fractions corresponding to specific nucleotides was determined. AXP and GXP denote total adenylate nucleotides and guanylate nucleotides, respectively. IMP was the only labeled nucleotide with hypoxanthine as precursor. 

Transfer RNA is present in cells as a population of polynucleotide molecules of about equal molecular weight (about 24,000) and equal lengths (about 70 nucleotides). Each of these molecules has an identical terminal acceptor three-nucleotide group (cytosyl-cytosyl-adenyl nucleotide, CCA), taking part independently in metabolism, and functioning as the point of attachment of the amino acid residue. The remainder of the polynucleotide portion of each... 

K. C. Ecistwell and P. K. Stumpf, Regulation of plant acetyl-CoA CeU boxylcise by adenylate nucleotides, Plant Physiol. 72 50 (1983). 

Regulation by variation of the adenine nucleotide pool or the NAD/ NADH ratio appears to be of particular physiologic import, since the adenylate nucleotides represent the principal storage form of chemical energy, while the pyridine nucleotides are the major source of reducing potential in the cell. With the two pools linked via electron transport and oxidative phosphorylation, any perturbation which affects either of the pools may have wide-ranging consequences on diverse reactions... 

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