High-energy phosphates inhibition

The Li+-induced inhibition of the production of the HSV virus may be related to its actions upon viral DNA polymerase production and activity. Li+ reduces both the synthesis of DNA polymerase in tissue culture and the activity of DNA polymerase in vitro, each by about 50%. It has been proposed that Li+ reduces the biosynthesis of viral polypeptides and nucleic acids, and hence inhibits viral DNA replication by competition with Mg2+, a cofactor of many enzymes [243]. However, the inhibitory effect of Li+ on HSV replication in tissue culture is not affected by Mg2+ levels. A more likely hypothesis is the alteration of the intracellular K+ levels, possibly modifying levels of the high-energy phosphate compounds by replacement of either Na+ or K+ in Na+/K+-ATPase [244]. In tissue culture, HSV replication has been shown to be affected by the... 

Brown AH, Niles NR, Braimbridge MV, Austen WG (1972) The combination of adenosine-triphosphatase inhibition and provision of high-energy phosphates for the preservation of unperfused myocardium, assessed by ventricular function, histology and birefringence. J Cardiovasc Surg 13 602-616... 

This relationship allows inhibition of glycolysis, with consequent activation of gluconeogenesis, specifically in gluconeogenic tissues, when ample energy and substrates are available. Control at the pyruvate kinase step allows conservation of high-energy phosphate in the phosphoenolpyruvate molecule. 

How the mitochondria can enhance nitrite reduction in leaves in the dark is not known as the bulk of the experimental evidence indicates that nitrite reductase is localized in the chloroplast. The reductant is ferredoxin generated by light or by the NADPH-ferredoxin reductase and an unknown NADPH-generating system in the dark. The inhibition of nitrite reduction by DNP and arsenate (Kessler and Bucker, 1960 Kessler, 1964 Hattori and Myers, 1966) has been interpreted to implicate a high energy phosphate requirement in nitrite reduction. One can speculate that the role of ATP could be to form an active nitrite required for reduction or to facilitate the entry of nitrite into the chloroplast. 

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