By using stereospecifically double-labelled radioactive mevalonates it was shown that betulaprenols-6 to -9, found in the woody tissue of Betula verrucosa, each contain three biogenetically trans-isoprene residues and that the remaining residues are biogenetically cis. The results obtained with these radioactive mevalonates also indicated that the activity of isopentenyl pyrophosphate isomerase...

Inorganic pyrophosphate promoted the acidification of an intracellular compartment in permeabilized procyclic trypomastigotes of Trypanosoma brucei, as measured by acridine orange uptake. The proton gradient generated by pyrophosphate was collapsed by addition of nigericin or NH(4)Cl. Pyrophosphate-driven proton translocation was stimulated by potassium ions and inhibited by KF, by the pyrophos...

The binding of pyrophosphate to myosin, heavy meromyosin, and Subfragment 1 was studied by an equilibrium dialysis technique. Myosin binds approximately 2 (1.82) moles/5 X lo5 g of protein, K = 2.07 X 10”. Identical results were obtained with myosin prepared by the ammonium sulfate precipitation procedure with or without LiCl and the dilution method. Red and white skeletal muscle myosin bound t...

A trans-farnesyl pyrophosphate-squalene synthetase has been isolated in a soluble form from yeast extracts and purified 45fold. The molecular weight of the enzyme estimated from sucrose density gradient centrifugation and gel filtration chromatography is 426,000. Solubilization of the squalene synthetase is achieved with deoxycholate. Treatment with the detergent markedly lowers squalene synthe...

High field (31)P nuclear magnetic resonance spectroscopy showed that inorganic pyrophosphate (P(2)O(7)(4-)) is more abundant than ATP in Trypanosoma cruzi, the causative agents of Chagas' disease. These results were confirmed by specific analytical assays, which showed that in epimastigotes, the concentrations of inorganic pyrophosphate and ATP were 194.7 +/- 25.9 and 37.6 +/- 5.5 nmol/mg of pr...

An Arabidopsis thaliana gene (AtLPP1) was isolated on the basis that it was transiently induced by ionizing radiation. The putative AtLPP1 gene product showed homology to the yeast and mammalian lipid phosphate phosphatase enzymes and possessed a phosphatase signature sequence motif. Heterologous expression and biochemical characterization of the AtLPP1 gene in yeast showed that it encoded an e...

The binding affinity for pyrophosphate (PPi) in aqueous media by N -alkyl ammonium resorcinarene salts can be enhanced via using weakly coordinating counter anions and modifying the upper rims of receptors lower rim hydroxyl groups.

The biochemical inhibition by Cu2+ on eight phylogenetically and biochemically different phosphofructokinases (PFKs) was investigated. The enzymes screened included representatives from thermophilic and mesophilic bacteria, a hyperthermophilic archaeon and a eukaryote, covering all three phosphoryl donor subtypes (ATP, ADP and pyrophosphate). The sensitivities of the enzymes to Cu2+ varied grea...