138-08-9Relevant academic research and scientific papers
ENOblock does not inhibit the activity of the glycolytic enzyme enolase
Satani, Nikunj,Lin, Yu-Hsi,Hammoudi, Naima,Raghavan, Sudhir,Georgiou, Dimitra K.,Muller, Florian L.
, (2016)
Inhibition of glycolysis is of great potential for the treatment of cancer. However, inhibitors of glycolytic enzymes with favorable pharmacological profiles have not been forthcoming. Due to the nature of their active sites, most high-affinity transition-state analogue inhibitors of glycolysis enzymes are highly polar with poor cell permeability. A recent publication reported a novel, non-active site inhibitor of the glycolytic enzyme Enolase, termed ENOblock (N-[2-[2- 2-aminoethoxy)ethoxy]ethyl]4-4-cyclohexylmethyl)amino]6-4-fluorophenyl)methyl]amino] 1,3,5-triazin-2-yl]amino]benzeneacetamide). This would present a major advance, as this is heterocyclic and fully cell permeable molecule. Here, we present evidence that ENOblock does not inhibit Enolase enzymatic activity in vitro as measured by three different assays, including a novel 31P NMR based method which avoids complications associated with optical interferences in the UV range. Indeed, we note that due to strong UV absorbance, ENOblock interferes with the direct spectrophotometric detection of the product of Enolase, phosphoenolpyruvate. Unlike established Enolase inhibitors, ENOblock does not show selective toxicity to ENO1-deleted glioma cells in culture. While our data do not dispute the biological effects previously attributed to ENOblock, they indicate that such effects must be caused by mechanisms other than direct inhibition of Enolase enzymatic activity.
Pyruvate ester composition and method of use for resuscitation after events of ischemia and reperfusion
-
, (2008/06/13)
A therapeutic composition comprising an alkyl, aralkyl, alkoxyalkyl or carboxyalkyl ester of 2-ketoalkanoic acid and a component for inducing and stabilizing the enol resonance form of the ester at physiological pH values is disclosed. The composition of the invention further comprises a pharmceutically acceptable carier vehicle in which the enol resonance form of the ester is stabilized at physiological pH values. Formulations containing the compositions of the invention permit the successful use of 2-ketoalkanoic acid esters, e.g., pyruvic acid esters, to treat, e.g., ischemic events, shock, organ reanimation, resuscitation and other recognized pyruvate-effective treatments. The compositions of the inventions are also useful in a process for preserving organ parts, organs or limbs removed from a living mammal and in need of preservation, e.g., for later transplantation to an organ recipient.
Thermodynamics of the hydrolysis reactions of adenosine 3′,5′-(cyclic)phosphate(aq) and phosphoenolpyruvate(aq); the standard molar formation properties of 3′,5′-(cyclic)phosphate(aq) and phosphoenolpyruvate(aq)
Goldberg, Robert N.,Tewari, Yadu B.
, p. 1809 - 1830 (2007/10/03)
Molar calorimetric enthalpy changes ΔrHm(cal) have been measured for the biochemical reactions {cAMP(aq) + H2O(l) = AMP(aq)} and {PEP(aq) + H2O(l) = pyruvate(aq) + phosphate(aq)}. The reactions were catalyzed, respectively, by phosphodiesterase 3prime;,5prime;-cyclic nucleotide and by alkaline phosphatase. The results were analyzed by using a chemical equilibrium model to obtain values of standard molar enthalpies of reaction ΔrHmo for the respective reference reactions {cAMp-(aq) + H2O(l) = HAMP-(aq)} and {PEP3-(aq) + H2O(l) = pyruvate-(aq) + HPO42-(aq)}. Literature values of the apparent equilibrium constants K′ for the reactions {ATP(aq) = cAMP(aq) + pyrophosphate(aq)K {ATP(aq) + pyruvate(aq) = ADP(aq) + PEP(aq)}, and {ATP(aq) + pyruvate(aq) + phosphate(aq) = AMP(aq) + PEP(aq) + pyrophosphate(aq)} were also analyzed by using the chemical equilibrium model. These calculations yielded values of the equilibrium constants K and standard molar Gibbs free energy changes ΔrGmo for ionic reference reactions that correspond to the overall biochemical reactions. Combination of the standard molar reaction property values (K, ΔrH mo, and ΔrGmo) with the standard molar formation properties of the AMP, ADP, ATP, pyrophosphate, and pyruvate species led to values of the standard molar enthalpy ΔfHmo, and Gibbs free energy of formation ΔfGmo and the standard partial molar entropy Smo of the cAMP and PEP species. The thermochemical network appears to be reasonably well reinforced and thus lends some confidence to the accuracy of the calculated property values of the variety of species involved in the several reactions considered herein. Published by Elsevier Ltd.
Nonenzymatic breakdown of the tetrahedral (α-carboxyketal phosphate) intermediates of MurA and AroA, two carboxyvinyl transferases. Protonation of different functional groups controls the rate and fate of breakdown
Byczynski, Bartosz,Mizyed, Shehadeh,Berti, Paul J.
, p. 12541 - 12550 (2007/10/03)
The mechanisms of nonenzymatic breakdown of the tetrahedral intermediates (THIs) of the carboxyvinyl transferases MurA and AroA were examined in order to illuminate the interplay between the inherent reactivities of the THIs and the enzymatic strategies used to promote catalysis. THI degradation was through phosphate departure, with C-O bond cleavage. It was acid catalyzed and dependent on the protonation state of the carboxyl of the α-carboxyketal phosphate functionality, with ionizations at pKa = 3.2 ± 0.1 and 4.3 ± 0.1 for MurA and AroA THIs, respectively. The solvent deuterium kinetic isotope effect for MurA THI at pL 2.0 was 1.3 ± 0.4, consistent with general acid catalysis. The pKa's suggested intramolecular general acid catalysis through protonation of the bridging oxygen of the phosphate, though H3O+ catalysis was also possible. The product distribution varied with pH. The dominant breakdown products were {pyruvate + phosphate + R-OH} (R-OH = UDP-GlcNAc or shikimate 3-phosphate) at all pH's, particularly low pH. At higher pH's, increasing proportions of ketal, arising from intramolecular substitution of phosphate by the adjacent hydroxyl and the enolpyruvyl products of phosphate elimination were observed. With MurA THI, the product distribution fitted to pK a's 1.6 and 6.2, corresponding to the expected pKa's of a phosphate monoester. C-O bond cleavage was demonstrated by the lack of monomethyl [33P]phosphate formed upon degrading MurA [ 33P]THI in 50% methanol. General acid catalysis through the bridging oxygen is consistent with the location of the previously proposed general acid catalyst for THI breakdown in AroA, Lys22.
Evidence for an Intramolecular, Stepwise Reaction Pathway for PEP Phosphomutase Catalyzed P-C Bond Formation
McQueney, Michael S.,Lee, Sheng-lian,Swartz, William H.,Ammon, Herman L.,Mariano, Patrick S.,Dunaway-Mariano, Debra
, p. 7121 - 7130 (2007/10/02)
The Tetrahymena pyriformis enzyme, phosphoenolpyruvate phosphomutase, catalyzes the rearrangement of phosphoenolpyruvate to the P-C bond containing metabolite, phosphonopyruvate.To distinguish between an intra- and intermolecular reaction pathway for this process an equimolar mixture of 18O,C(2)-18O>thiophosphonopyruvate and (all 16O) thiophosphonopyruvate was reacted with the phosphonomutase, and the resulting products were analyzed by 31P NMR.The absence of the cross-over product 18O>thiophosphonoenolpyruvate in the product mixture was interpreted as evidence for an intramolecular reaction pathway.To distinguish between a concerted and stepwise intramolecular reaction pathway the pure enantiomers of the chiral substrate 18O>-thiophosphonopyruvate were prepared and the stereochemicalb course of their conversion to chiral 18O>thiophosphoenolpyruvate was determined.The assignments of the phosphorous configurations in the 18O>thiophosphonopyruvate enantiomers reported earlier (McQueney, M.S.; Lee, S.-l.; Bowman, E.; Mariano, P.S.; Dunaway- Mariano, D.J.Am.Chem.Soc. 1989, 111, 6885-6887) were revised according to the finding that introduction of the 18O label into the thiophosphonopyruvate precursor occurs with retention rather than with (the previously assumed) inversion of configuration.On the basis the observed conversion of (Sp)-18O>thiophosphonopyruvate to (Sp)-18O>thiophosphonoenolpyruvate and (Rp)-18O>thiophosphonopyruvate to (Rp)-18O>thiophosphonoenolpyruvate, it was concluded that the PEP phosphomutase reaction proceeds with retention of the phosphorus configuration and therefore by a stepwise mechanism.Lastly, the similar reactivity of the oxo- and thio-substituted phosphonopyruvate substrates (i.e., nearly equal Vmax) was interpreted to suggest that nucleophilic addition to the phosphorus atom is not rate limiting among the reaction steps.
Synthesis of Methoxycarbonyl Phosphate, a New Reagent Having High Phosphoryl Donor Potential for Use in ATP Cofactor Regeneration
Kazlauskas, Romas J.,Whitesides, George M.
, p. 1069 - 1076 (2007/10/02)
Reaction of an aqueous solution of phosphate ion (pH 7.8) with acetic anhydride in a two-phase system gives acetyl phosphate.Reaction of phosphate with methyl chloroformate yields methoxycarbonyl phosphate.Both reagents are useful for in situ regeneration of ATP from ADP in organic synthetic procedures based on enzyme-catalyzed reactions requiring ATP.Acetyl phosphate has been used for this purpose previously; methoxycarbonyl phosphate is a new compound, and its use in ATP regeneration is also new.The characteristics of methoxycarbonyl phosphate which makes it interesting are its ease of preparation, its acceptability as a substrate for both acetate kinase and carbamate kinase, and its high phosphoryl donor potential.It has the additional attractive feature that the product remaining after phosphoryl transfer, methyl carbonate, decomposes spontaneusly in solution and forms methanol and carbon dioxide.These products present no difficulties in workup and avoid the problem of product inhibition which is sometimes troublesome in regeneration schemes based on acetyl phosphate or phosphoenolpyruvate.The principal disadvantage of methoxycarbonyl phosphate as a phosphorylating reagent in ATP regeneration, relative to acetyl phosphate, is that it decomposes inconveniently rapidly under the conditions used for enzymatic synthesis (t1/2 = 0.3 h at 25 deg C, pH 7).
