Disease relevance of dihydroxy-oxido-oxo-phosphorane

• In an effort to determine whether the Na+-dependent Pi transport system of Ehrlich ascites tumor cells exhibits specificity for H2PO4- or HPO4(-2), Pi fluxes were determined by measuring 32Pi-Pi self-exchange [1].
• The dimeric L-2-haloacid dehalogenase from Pseudomonas sp. YL, (subunit mass, 26179 Da), has been crystallized by vapor diffusion, supplemented by repetitive seeding, against a 50 mM potassium dihydrogenphosphate solution (pH 4.5) containing 15% (w/v) polyethylene glycol 8,000 and 1% (v/v) n-propanol [2].
• Static exercise caused muscle acidosis and an increase in H2PO4-, whereas rhythmic exercise had no effect on muscle metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)[3]
• However, hypercapnic perfusion (70% CO2, pHo, 6.7, pHi 6.4-6.5) had no effect on peak tetanic force, and there was no significant correlation between pHi or [H2PO4-] during hypercapnia in either muscle [4].

High impact information on dihydroxy-oxido-oxo-phosphorane

• The highly significant linear relationship between increases of H+ and H2PO4- and the decline of MVC strongly suggests that both H+ and H2PO4- are important determinants of human muscle fatigue [5].
• Many of the essential metalloproteins are located in the cell, whose cytoplasmic fluid contains several small inorganic anions, such as Cl-, NO2-, NO3-, H2PO4-, and SO4(2-), that play an indispensable role in determining the cell's volume, regulating the cell's pH, signal transduction, muscle contraction, as well as cell growth and metabolism [6].
• o-quinone alpha-phenylmethide was generated as a short-lived transient species in aqueous solution by flash photolysis of o-hydroxy-alpha-phenylbenzyl alcohol, and its rate of decay was measured in HClO4 and NaOH solutions as well as in CH3CO2H, H2PO4-, and HCO3- buffers [7].
• Studies of the pH-dependence of phosphorylation show that H2PO4- and HPO4(2)- bind to the ATPase with equal affinity, but that only binding of H2PO4- leads to phosphorylation, described by an equilibrium constant of 2 [8].
• Mixed-type inhibition with H2PO4- is actually of the type called "partially mixed competitive and non-competitive' as the inhibitor binds both to the catalytic site and to the allosteric site [9].

Biological context of dihydroxy-oxido-oxo-phosphorane

• Thus, in both synthesis and hydrolysis of ATP, TFP and H2PO4- interact with a common site [10].
• Analysis of the H-bonding network around the bound inhibitor indicates that phosphate is bound as the H2PO4- anion, and that an additional proton is present on the Odelta2 atom of Asp(alpha363), an active site residue involved in Ni coordination through Odelta1 [11].
• Data on phosphate uptake during oxidative phosphorylation at several pH showed that H2PO4- is the true substrate for oxidative phosphorylation [10].
• It is supposed that changes in molecular structure affect the H+- and H2PO4- ion transporting function and may be part of the "gating" mechanism in phosphate transport [12].

Anatomical context of dihydroxy-oxido-oxo-phosphorane

• With a uniform pCO2 throughout the epithelium, the model variables include the concentrations of Na, K, Cl, HCO3, H2PO4, HPO4, and H, as well as hydrostatic pressure and electrical potential [13].
• To differentiate the effects of high energy phosphates, pH, and [H2PO4-] on skeletal muscle fatigue, intracellular acidosis during handgrip exercise was attenuated by prolonged submaximal exercise [14].
• Capillary zone electrophoresis was used for the separation of pilocarpine from its epimer, isopilocarpine, using coated fused-silica capillaries of 20 cm x 25 microm I.D., 8 kV running voltage, migration buffer of 0.1 M sodium dihydrogenphosphate pH 8, detection at 217 nm and injection by electromigration [15].
• METHODS: 120 extracted human premolars were randomly assigned to eight groups for bonding with the following self-etching agents: Prompt-L Pop, Adper Prompt, Clearfil SE, Prime& Bond NT with NRC, Xeno111, One-Up Bond, AdheSe, or Prime & Bond NT using a total etch technique (36% H2PO4) [16].

Associations of dihydroxy-oxido-oxo-phosphorane with other chemical compounds

• Inhibition by trifluoperazine of ATP synthesis and hydrolysis by particulate and soluble mitochondrial F1: competition with H2PO4- [10].
• The analytical method for the measurement of the fluorescent compound employed a Tosoh ODS 80 column eluted with 10 mM potassium dihydrogenphosphate (pH 4.5) and acetonitrile (3:2, v/v) and detection at an excitation wavelength of 375 nm (10 nm bandpass) and an emission wavelength of 455 nm (10 nm bandpass) [17].
• Aliquots of each solution were chromatographed on a reversed-phase column using a mobile phase of methanol-20 mM potassium dihydrogenphosphate (pH 6.4) (linear gradient from 0 to 100% methanol at 3%/min with a flow-rate of 1.5 ml/min) on a liquid chromatograph equipped with an ultraviolet absorbance detector (254 nm) [18].
• On-line microdialysate was directly injected into a microbore column using a methanol-100 mM sodium dihydrogenphosphate (30:70, v/v, pH 2.5 adjusted with orthophosphoric acid) as the mobile phase and ultraviolet detection at 325 nm [19].
• The mobile phase was methanol-0.08 M phosphate buffer (pH 7.6) (20:80), which contained 0.01 M tetrabutylammonium dihydrogenphosphate [20].

Gene context of dihydroxy-oxido-oxo-phosphorane

• Thus VR1 and ASIC are likely to play a coordinated and interactive role in processing the muscle afferent response to H2PO4-. Furthermore, the physiological mechanisms mediating the response to H+ and H2PO4- are likely to be different [21].
• Thus we examined the role played by purinergic receptors, vanilloid type 1 receptors (VR1), and acid-sensing ion channels (ASIC) in mediating H2PO4- -evoked pressor responses [21].
• Separation of the investigated compound and internal standard was achieved on a Nucleosil 7 C18 column with a 0.01-M potassium dihydrogenphosphate buffer (pH 2.5)-methanol (60:40, v/v) mobile phase [22].
• Single crystal X-ray structures of L1 and [RuII(bipy)2(L2H)](H2PO4)3.(CH3)2CO.0.8H2O were obtained, the latter revealing the presence of H2PO4- counter anions, the source of which is presumed to be hydrolysis of PF6- ions [23].
• The on-line chromatographic separation was performed on a LiChrospher 100 RP8 5-microm particle size packed analytical column (25x0.4 cm I.D.). The mobile phase consisted of acetonitrile-0.01 M potassium dihydrogenphosphate (65:35, v/v) at a flow-rate of 0.8 ml/min [24].

Analytical, diagnostic and therapeutic context of dihydroxy-oxido-oxo-phosphorane

• Positive ion fast atom bombardment mass spectrometry of the diphosphoryl lipid A TLC-3 (a highly acylated major band) showed a major component with (M + H)+ ion of mass 1798, which fragmented to yield a (M - H2PO4)+ ion of mass 1700 [25].
• The HPLC separation was carried out on a Supersphere RP-18e column (125 X 4.0 mm I.D.) using 0.05 M sodium dihydrogenphosphate (pH 4.5)-acetonitrile (8:2) as the mobile phase at a flow-rate of 0.5 ml/min, and monitored with a photodiode-array detector [26].
• 31P magic angle spinning NMR confirmed the XPS data and also showed that the chemical shift of the (H2PO4)- ions strongly depended on the crystallization degree of the Nb2O5 [27].
• 1H NMR titrations demonstrated that while compound 1 hydrogen-bonded to H2PO4- forming simple 1 : 1 host-guest complex, further addition of F- induced the deprotonation of compound 1 [28].
• Urinary modified nucleosides were determined by capillary electrophoresis using a 300 mM SDS-25 mM sodium tetraborate-50 mM sodium dihydrogenphosphate buffer [29].

References