Use Of Pyrophosphate Research Articles

Pyrophosphate as a novel anticoagulant for storage of whole blood: A proof-of-concept study.

Citrate is the only anticoagulant currently Food and Drug Administration (FDA)-approved for the long-term storage of blood for transfusion. Citrate inhibits phosphofructokinase and may play a pro-inflammatory role, suggesting that there may be an advantage to using alternative anticoagulants. Here, we examine the use of pyrophosphate as an anticoagulant. Whole blood samples from healthy donors were anticoagulated either with citrate-phosphate-adenine-dextrose (CPDA-1) or our novel anticoagulant mixture pyrophosphate-phosphate-adenine-dextrose (PPDA-1). Samples were assessed for coagulation capacity by thromboelastography immediately after anticoagulation (T0) with and without recalcification, as well as 5 hours after anticoagulation (T1) with recalcification. Complete blood counts were taken at both timepoints. Flow cytometry to evaluate platelet activation as well as blood smears to evaluate cellular morphology were performed at T1. No clotting was detected in samples anticoagulated with either solution without recalcification. After recalcification, clotting function was restored in both groups. R-Time in recalcified PPDA-1 samples was shorter than in CPDA-1 samples. A reduction in platelet count at T1 compared to T0 was observed in both groups. No significant platelet activation was observed in either group at T1. Blood smear indicated platelet clumping in PPDA-1. We have shown initial proof of concept that pyrophosphate functions as an anticoagulant at the dose used in this study, though there is an associated loss of platelets over time that may limit its usefulness for blood storage. Further dose optimization of pyrophosphate may limit or reduce the loss of platelets.

Metal-free auxiliary pyrophosphate detection based on near-infrared carbon dots

The excessive use of pyrophosphate (PPi) anions as additives poses a serious threat to human health and the environment. Considering the current status of PPi probes, the development of metal-free auxiliary PPi probes has important applications. In this study, a novel near-infrared nitrogen and sulfur co-doped carbon dots (N,S-CDs) were prepared. The average particle size of N,S-CDs was 2.25 ± 0.32 nm with average height was 3.05 nm. The probe N,S-CDs showed a special response to PPi, and a good linear relationship was obtained with PPi concentrations ranging from 0 to 1 μM, with the limit of detection being 0.22 nM. Tap water and milk were used for practical inspection, and ideal experimental results were acquired. In addition, the probe N,S-CDs also showed good results in biological systems, such as cell and zebrafish experiments.

Near-equilibrium glycolysis supports metabolic homeostasis and energy yield.

Glycolysis plays a central role in producing ATP and biomass. Its control principles, however, remain incompletely understood. Here, we develop a method that combines 2H and 13C tracers to determine glycolytic thermodynamics. Using this method, we show that, in conditions and organisms with relatively slow fluxes, multiple steps in glycolysis are near to equilibrium, reflecting spare enzyme capacity. In Escherichia coli, nitrogen or phosphorus upshift rapidly increases the thermodynamic driving force, deploying the spare enzyme capacity to increase flux. Similarly, respiration inhibition in mammalian cells rapidly increases both glycolytic flux and the thermodynamic driving force. The thermodynamic shift allows flux to increase with only small metabolite concentration changes. Finally, we find that the cellulose-degrading anaerobe Clostridium cellulolyticum exhibits slow, near-equilibrium glycolysis due to the use of pyrophosphate rather than ATP for fructose-bisphosphate production, resulting in enhanced per-glucose ATP yield. Thus, near-equilibrium steps of glycolysis promote both rapid flux adaptation and energy efficiency.

Use of pyrophosphate and boric acid additives in the copper-zinc alloy electrodeposition and chemical dealloying

Over the last decade, nanoporous metals have attracted a growing attention due to the combination of structural and functional properties, such as their very high surface to volume ratio and mechanical rigidity. A recent and versatile process producing nanoporous metals is the dealloying of an initial alloy, i.e. the selective dissolution of the more reactive element of the alloy. In this work, we report on a method of CuZn alloy formation, without the use of furnaces or expensive techniques, and its subsequent chemical dealloying leading to nanoporous copper. Co-electrodeposition of CuZn alloys on a copper substrate is performed using pyrophosphate as a complexing agent in presence of boric acid, copper sulfate and zinc sulfate. The electrochemical behavior of this system is characterized by cyclic voltammetry, showing that a copper-zinc alloy is formed at −1.5 V vs. SCE. Cauliflower-like Zn-rich γ-brass and ε-brass coatings are obtained by co-electrodeposition. The thickness, the structure and the composition of the electrodeposited alloy can be tuned by varying the electrodeposition conditions. Thicker and rougher coatings with a higher zinc content are formed at more cathodic conditions. The electrodeposited CuZn coatings were chemically dealloyed, and a two-step dealloying protocol leads to open-framework nanoporous copper templates, which are a material of interest for energy storage, biosensors, and catalysis applications.

Evaluation of Natural and Synthetic Phosphate Donors for the Improved Enzymatic Synthesis of Phosphate Monoesters.

Undesired product hydrolysis along with large amounts of waste in form of inorganic monophosphate by‐product are the main obstacles associated with the use of pyrophosphate in the phosphatase‐catalyzed synthesis of phosphate monoesters on large scale. In order to overcome both limitations, we screened a broad range of natural and synthetic organic phosphate donors with several enzymes on a broad variety of hydroxyl‐compounds. Among them, acetyl phosphate delivered stable product levels and high phospho‐transfer efficiency at the lower functional pH‐limit, which translated into excellent productivity. The protocol is generally applicable to acid phosphatases and compatible with a range of diverse substrates. Preparative‐scale transformations using acetyl phosphate synthesized from cheap starting materials yielded multiple grams of various sugar phosphates with up to 433 g L−1 h−1 space‐time yield and 75% reduction of barium phosphate waste.

Pyrophosphate Interactions at the Transition States of Plasmodium falciparum and Human Orotate Phosphoribosyltransferases

Orotate phosphoribosyltransferases from Plasmodium falciparum and human sources (PfOPRT and HsOPRT) use orotidine as a slow substrate in the pyrophosphorolysis reaction. With orotidine, intrinsic kinetic isotope effects (KIEs) can be measured for pyrophosphorolysis, providing the first use of pyrophosphate (PPi) in solving an enzymatic transition state. Transition-state structures of PfOPRT and HsOPRT were solved through quantum chemical matching of computed and experimental intrinsic KIEs and can be compared to transition states solved with pyrophosphate analogues as slow substrates. PfOPRT and HsOPRT are characterized by late transition states with fully dissociated orotate, well-developed ribocations, and weakly bonded PPi nucleophiles. The leaving orotates are 2.8 A distant from the anomeric carbons at the transition states. Weak participation of the PPi nucleophiles gives C1'-O(PPi) bond distances of approximately 2.3 A. These transition states are characterized by C2'-endo ribosyl pucker, based on the beta-secondary [2'-(3)H] KIEs. The geometry at the 5'-region is similar for both enzymes, with C3'-C4'-C5'-O5' dihedral angles near -170 degrees . These novel phosphoribosyltransferase transition states are similar to but occur earlier in the reaction coordinate than those previously determined with orotidine 5'-monophosphate and phosphonoacetic acid as substrates. The similarity between the transition states with different substrate analogues supports similar transition state structures imposed by PfOPRT and HsOPRT even with distinct reactants. We propose that the transition state similarity with different nucleophiles is determined, in part, by the geometric constraints imposed by the catalytic sites.

Tetranuclear pyrophosphate-bridged Cu(II) complex with 2,2′-dipyridylamine: Crystal structure, spectroscopy and magnetism

Use of pyrophosphate, 2,2′-dipyridylamine (hdpa) with Cu(NO 3) 2 · 3H 2O has enabled to synthesize a novel tetranuclear copper(II) complex, [Cu 4(hdpa) 4(μ-P 2O 7) 2] · 11H 2O 1, which was characterized by single crystal X-ray diffraction, IR, ESR spectrum, and variable-temperature magnetic susceptibilities (4.2–300 K). Extensive π–π stackings and H-bonding water clusters resulting from 11 free water molecules join Cu 4 units to make a 3D network. According to the molecular structure, the experimental data were fitted to the expressions derived from the Hamiltonian H = - 2 J 12 S ^ 1 S ^ 2 - 2 J 13 ( S ^ 1 S ^ 3 + S ^ 2 S ^ 4 ) - 2 J 14 ( S ^ 1 S ^ 4 + S ^ 2 S ^ 4 ) showing dominant antiferromagnetic behaviors.

THE ORGANIZATION AND REGULATION OF PLANT GLYCOLYSIS.

This review discusses the organization and regulation of the glycolytic pathway in plants and compares and contrasts plant and nonplant glycolysis. Plant glycolysis exists both in the cytosol and plastid, and the parallel reactions are catalyzed by distinct nuclear-encoded isozymes. Cytosolic glycolysis is a complex network containing alternative enzymatic reactions. Two alternate cytosolic reactions enhance the pathway's ATP yield through the use of pyrophosphate in place of ATP. The cytosolic glycolytic network may provide an essential metabolic flexibility that facilitates plant development and acclimation to environmental stress. The regulation of plant glycolytic flux is assessed, with a focus on the fine control of enzymes involved in the metabolism of fructose-6-phosphate and phosphoenolpyruvate. Plant and nonplant glycolysis are regulated from the "bottom up" and "top down," respectively. Research on tissue- and developmental-specific isozymes of plant glycolytic enzymes is summarized. Potential pitfalls associated with studies of glycolytic enzymes are considered. Some glycolytic enzymes may be multifunctional proteins involved in processes other than carbohydrate metabolism.

Drug-induced Ca2+ release from isolated sarcoplasmic reticulum. I. Use of pyrophosphate to study caffeine-induced Ca2+ release.

A demonstration is made of pyrophosphate's use as a precipitating anion in studies of Ca2+ release from isolated sarcoplasmic reticulum (SR). Not only does pyrophosphate speed up the rate at which Ca2+ can be preloaded into SR, but it also allows the accumulated Ca2+ to be released in response to agents such as caffeine. Because so much Ca2+ can be preloaded into SR with pyrophosphate present, more experiments can be performed with a given amount of SR material, and even rapid Ca2+ release rates (greater than 1 mumol/mg X min) are maintained for many seconds. These rates can easily be quantified using conventional spectrophotometric and isotopic methods, without the need for expensive rapid mixing equipment. Caffeine-induced Ca2+ release is exhibited by triadic and terminal cisterna SR subfractions but not by light SR. Caffeine specifically increases the rate of unidirectional 45Ca2+ efflux. This increased efflux is blocked by ruthenium red at submicromolar concentrations and by tetracaine, 9-aminoacridine, or Ba2+ at submillimolar concentrations.

Ferrihydrite in pyrophosphate extracts of podzol B horizons

The amount of Fe and Al extracted from soil by 0·1 M pyrophosphate (Fep, Alp) has long been used as a criterion in the designation of spodic horizons of podzols (Avery, 1973). Although Adamset al.(1980) showed that in a group of podzolic soils developed from Lower Palaeozoic sedimentary (LPS) rocks Fepwas very closely correlated with the quantities of Fe eluviated and illuviated, such evidence validating the use of pyrophosphate is not generally available. Recently there has been renewed interest in the identification of forms of Fe and Al extracted by pyrophosphate in order that greater confidence might be gained in the use of Fepand Alpin soil classification (McKeague & Schuppli, 1982).Our interest in pyrophosphate extraction was stimulated when Nto (1981) discovered that Fepwas an excellent predictor of P sorption in soils developed from LPS rocks. Indeed, the level of predictability was not improved by the inclusion, in multiple regressions, of either Fe or Al extracted by any other of the commonly used selective extractants.

Use of Pyrophosphate Labelled with 99mTc in the Scintigraphic Diagnosis of Myocardial Infarction

SummaryScintigraphy of acute myocardial infarction 1 hr after intravenous administration of pyrophosphate labeled with 99m Tc suitably complements the classical diagnostic methods. A delay longer than that does not improve the quality of the scan. An acute lesion can be detected within 24 hours to 1 week after its development.

Contracture and twitch potentiation of fast and slow muscles of the rat at 20 and 37 C.

Contracture and twitch potentiation of fast and slow muscles of the rat at 20 and 37 C.

Pyrophosphate enhancement of thyrocalcitonin effect in tissue culture.

In vitro bone culture technique was developed by the modification of the Goldhaber's method. Using this method, pyrophosphate was found to inhibit PTH induced bone resorption as judged by the release of previously incorporated Ca45 into the medium and by the histological findings. Furthermore, addition of pyrophosphate markedly enhanced the thyrocalcitonin inhibition of bone resorption in this system. These findings, together with the previous findings that pyrophosphate enhances the hypocalcemic response to TC in vivo, strongly suggest the favorable effect of the combined use of pyrophosphate and TC in the bone diseases characterized by excessive bone resorption.

The mechanical analysis of soils in general and the effect of anions on the dispersibility of lateritic soils in particular.

The technique of mechanical analysis is critically discussed with a view to standardizing the procedure, and effects of the concentration of dispersing agent in the suspension and the importance of the anion and pH in the degree of dispersion in lateritic soils are dealt with. The use of pyrophosphate or hexametaphosphate in preference to oxalate as dispersing agent for lateritic soils is advocated, and the role of P2O7 and PO3 ions is compared to that of the OH ion in the deflocculation of these soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)