Pyrophosphorylase activation

Lin, T. P.. Caspar, T., Somerville, C., and Preiss, J. 1988a. A starch deficient mutant of Arabidopsis thaliana with low ADPglucose pyrophosphorylase activity lacks one of the two subunits of the enzyme. Plant Physiol. 88,1175-1181. 

Tsai, C. Y., and Nelson, O. E. 1966. Starch-deficient maize mutant lacking adenosine diphosphate glucose pyrophosphorylase activity. Science 151, 341-343. 

The assay was used to determine NAD pyrophosphorylase activity in extracts prepared from human chronic myelogenous leukemia cells, and in extracts prepared from rat tissues. 

Smidansky ED, Clancy M, Meyer FD, Lanning SP, Blake NK, Talbert LE, Giroux MJ. Enhanced ADPglucose pyrophosphorylase activity in wheat endosperm increases seed yield. Proc. Natl. Acad. Sci. U. S. A. 2002 99 1724-1729. 

The alkaloids interfere with a number of enzyme systems. In vitro, lasiocarpine and heliotrine inhibit enzyme systems that need pju idine nucleotides for electron transfer (45). The nicotinamide-adenine dinucleotide pyrophosphorylase activity of nuclei from rat liver that has been treated with heliotrine is reduced significantly below that of controls (46). It has recently been shown that in rats lasiocarpine inhibits RNA synthesis, causes a substantial reduction in tryptophan pyrrolase activity, and decreases the activity of RNA polymerase (47). 

The GMP activity that is used in alginate synthesis is associated with the algA gene product, which also catalyzes the PMI reaction. The first indications that AlgA is bifunctional came when the protein was purified. The isomerase and pyrophosphorylase activities co-purified, and their activities remained in constant ratio throughout the purification. Brief treatment with chymotrypsin cleaved approximately 1 kDa from the C-terminus of AlgA the remaining protein retained GDP-pyrophosphorylase activity, but the phosphoman-nose isomerase activity was lost. ... 

Saccharomyces cerevisiae (mutant resistant to 2-amino-4-methyl-5- -hy-droxyethylthiazole, an antimetabolite of 4-methyl-5-/l-hydroxyethylthia-zole, deficient in activity of both EC 2.5.1.3 and EC 2.7.1.50 [2] bifunctional enzyme with hydroxyethylthiazole kinase and thiamine-phosphate pyrophosphorylase activity [2]) [1, 2]... 

It has been shown that soluble, enzyme preparations from mung beans, peas, and other plants show pyrophosphorylase activity, and can form GDP-D-glucose from GTP and a-D-glucosyl phosphate. These enzyme preparations also contain various carbohydrate compounds, including small proportions of cellulose, that could act as acceptor. Therefore, it was postulated that cellulose in higher plants is formed through the following reactions. ... 

On the basis of these findings, the investigators concluded that pyrophosphorylase activity controls the rate of NAD biosynthesis, and, therefore, its concentration in the bacterial cell and that the activity of that enzyme is regulated by repressive genes. 

Pyrophosphorylase activity of the DNA has been determined by an indirect and a direct approach. In the indirect one, the PPj exchange with deoxynucleo-side triphosphate is measured. In the direct approach, cleavage of DNA to the respective pyrophosphatase is assayed. 

The pyrophosphorylase activity attacks the 3 -OH group and requires primer, template, and triphosphate in the incubation mixture. 

Littlefield, J. W. (1963), The inosinic acid pyrophosphorylase activity of mouse fibroblasts partially resistant to 8-azaguanine, Proc. Natl. Acad. Sci. 50, 568-576. 

Hi) Pyrophosphorolysis. The pyrophosphorylase activity is optimal at pH 6.5 (2). At pH 6.0, pyrophosphorolysis is 5 times more active than hydrolysis. However, at pH 9.2 (sodium glycinate), which is optimal for both 5 -nuclease and 3 5 -exonuclease activities, pyrophosphorolysis is 150 times slower than... 

M. D. Alonso, J. Lomako, W. M. Lomako, W. J. Whelan, J. Preiss, Properties of carbohydrate-free recombinant glycogenin expressed in an Escherichia coli mutant lacking UDP-glucose pyrophosphorylase activity FEBS Lett. 352 1994, 222-6. 

Rat anti-human IMP pyrophosphorylase globulin (AB) was obtained by adding solid ammonium sulfate to immune serum (50% saturation). The reaction was carried out by adding to DEAE-cellulose treated blood to appropriate amounts of DEAE-cellulose treated Lesch-Nyhan blood and potassium phosphate buffer 0.01 M, pH 7.0, to a final volume of 250 [xl. The mixture was incubated at 4 for 16 hours, centrifuged at 2000 RPM for 30 minutes and 50 Jil of the supernatant was assayed for IMP pyrophosphorylase activity. 

DAVIES, J. (1969). Elevated AMP pyrophosphorylase activity in congenital IMP pyrophosphorylase deficiency (Lesch-Nyhan disease. J. Lab. Clin. Med. 7 732-7 1. 

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