56-65-5Relevant articles and documents
Analytical Techniques for the Determination of Chemical Exchange Rate Constants with Application to the Creatine Kinase Reaction
Sorce, Dennis J.,Sciacca, Robert R.,Keller, Andrew M.
, p. 230 - 241 (1990)
A method for determining biochemical exchange rates for analysis of inversion recovery experiments is described.As used in the current application, the technique involves fitting multiexponential equations to the magnetization recovery curves for PCr and ATP.From the parameters of the exponential fits expressions for the forward and reverse rate constants are derived.Results obtained with this technique were compared with inversion transfer and with previously published results using saturation transfer.The addition of a third exchanging species was also investigated and found to have no significant effect on the calculated values for the forward and reverse rate constants.In addition, the feasibility of using an abbreviated 6-point sampling strategy was evaluated; values for the rate constants were similar to those obtained using all 21 data points.The results of this study indicate that chemical exchange rate constants can be determined using inversion recovery techniques which avoid many of the difficulties associated with selective excitation methods.
Practical Enzymatic Synthesis of Adenosine 5'-O-(3-Thiotriphosphate) (ATP-γ-S)
Abril, Obsidiana,Crans, Debbie C.,Whitesides, George M.
, p. 1360 - 1364 (1984)
An enzymatic procedure for the synthesis of adenosine 5'-O-(3-thiotriphosphate) (ATP-γ-S) on a 50-mmol scale from dihydroxyacetone, sodium thiophosphate, ADP, and phosphoenol pyruvate is described.The synthesis uses polyacrylamide gel immobilized glycerokinase coupled to a pyruvate kinase catalyzed ATP cofactor regeneration system, and polyacrylamide gel immobilized triosephosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, and phosphoglycerate kinase coupled to a lactate dehydrogenase catalyzed NAD cofactor regeneration system.The ATP-γ-S is purified by adsorption on Dowex 1 and isolated as the sodium or barium salts in ca. 90 percent purity.
Graphene oxide enhanced specificity at aptamer and its application to multiplexed enzymatic activity sensing
Xing, Xiaojing,Liu, Xueguo,Zhou, Ying,Xu, Dangdang,Pang, Daiwen,Tang, Hongwu
, p. 11815 - 11821 (2016)
We explore the effect of sufficient GO on the property of a dye labeled adenosine 5′-triphosphate (ATP) aptamer (P) which shows similar affinity and specificity for ATP and its analogues including adenosine 5′-diphosphate (ADP), adenosine 5′-monophosphate (AMP), and adenosine (AD). It is found that ATP and its analogues give rise to fluorescence recovery of GO-quenched P to a different extent (in the order of ATP > AD > ADP > AMP), and the difference becomes larger when increasing the concentration of GO in a certain range, implying an improvement of specificity of the ATP aptamer. Based on this finding, a fluorescence turn-on assay for alkaline phosphatase (ALP) and creatine kinase (CK) is proposed, by using AMP and ADP as the substrate, respectively. Specifically, the GO-quenched P system containing substrate shows low fluorescence intensity. In the presence of target enzyme, the substrate is converted into either AD or ATP which have higher affinity with P, resulting in stronger fluorescence of the mixture of P and GO. The entire assay is sensitive and selective. More importantly, the ability of GO with suitable concentration to improve the specificity of aptamers not only offers an exciting new way to detect protease, but also is valuable for developing the application of GO and aptamers in the biosensing field and is expected to be used in aptamer screening systems, to improve the specificity of screened aptamers.
Design, synthesis, and anticancer activity of phosphonic acid diphosphate derivative of adenine-containing butenolide and its water-soluble derivatives of paclitaxel with high antitumor activity
Moosavi-Movahedi, Ali A.,Hakimelahi, Shahram,Chamani, Jamshid,Khodarahmi, Ghadam Ali,Hassanzadeh, Farshid,Luo, Fen-Tair,Ly, Tai Wei,Shia, Kak-Shan,Yen, Chi-Feng,Jain, Moti L.,Kulatheeswaran, Ramasamy,Xue, Cuihua,Pasdar, Manijeh,Hakimelahi, Gholam Hossein
, p. 4303 - 4313 (2003)
Synthesis of adenine derivative of triphosphono-γ -(Z)-ethylidene-2,3-dimethoxybutenolide 4 was accomplished by treatment of phosphonate 3 with 5-phosphoribosyl 1-pyrophosphate in the presence of 5-phosphoribosyl 1-pyrophosphate synthetase. It was found that triphosphonate 4 functions as an irreversible stoichiometric inactivator of the Escherichia coli ribonucleoside diphosphate reductase (RDPR). Triphosphonate 4 exhibited potent inhibitory activity against murine leukemias (L1210 and P388), breast carcinoma (MCF7), and human T-lymphoblasts (Molt4/C8 and CEM/0) cell lines. Paclitaxel ester derivatives of adenine-containing triphosphono-γ -(Z)-ethylidene-2,3-dimethoxybutenolide 8-10 were also synthesized. Like triphosphonate 4, compound 8 exhibited inhibitory property toward RDPR. It also induced microtubule assembly similar to paclitaxel (5). The structure of the chlorodiester linker in 8 was found to account for this dual property. After treatment of MCF7 cells with compounds 4, 5, and 8, fluorescence microscope examination demonstrated the presence of nucleus shrinkage or segmentation. Bifunctional prodrug 8 exhibited higher lipophilicity than 4 and higher water-solubility than 5. Pro-dual-drug 8 exhibited more pronounced anticancer activity relative to that of the triphosphonate 4 and paclitaxel (5). In contrast, compound 9, resulting from the linkage of triphosphonate 4 and paclitaxel (5) through a diester unit, was only found to function as a highly water-soluble prodrug for paclitaxel (5). It induced microtubule assembly in vitro, but did not show inhibitory property toward RDPR. On the other hand, compound 10, an aggregate of triphosphonate 4 and paclitaxel (5), neither functioned as an inhibitor of RDPR nor exhibited microtubule assembly stimulating activity in vitro.
Conformational dynamics and allostery in pyruvate kinase
Donovan, Katherine A.,Zhu, Shaolong,Liuni, Peter,Peng, Fen,Kessans, Sarah A.,Wilson, Derek J.,Dobson, Renwick C.J.
, p. 9244 - 9256 (2016)
Pyruvate kinase catalyzes the final step in glycolysis and is allosterically regulated to control flux through the pathway. Two models are proposed to explain how Escherichia coli pyruvate kinase type 1 is allosterically regulated: the "domain rotation model" suggests that both the domains within the monomer and the monomers within the tetramer reorient with respect to one another; the "rigid body reorientation model" proposes only a reorientation of the monomers within the tetramer causing rigidification of the active site. To test these hypotheses and elucidate the conformational and dynamic changes that drive allostery, we performed time-resolved electrospray ionization mass spectrometry coupled to hydrogen-deuterium exchange studies followed by mutagenic analysis to test the activation mechanism. Global exchange experiments, supported by thermostability studies, demonstrate that fructose 1, 6-bisphosphate binding to the allosteric domain causes a shift toward a globally more dynamic ensemble of conformations. Mapping deuterium exchange to peptides within the enzyme highlight site-specific regions with altered conformational dynamics, many of which increase in conformational flexibility. Based upon these and mutagenic studies, we propose an allosteric mechanism whereby the binding of fructose 1, 6-bisphosphate destabilizes an α-helix that bridges the allosteric and active site domains within the monomeric unit This destabilizes the βstrands within the (β/α)8-barrel domain and the linked active site loops that are responsible for substrate binding. Our data are consistent with the domain rotation model but inconsistent with the rigid body reorientation model given the increased flexibility at the interdomain interface, and we can for the first time explain how fructose 1, 6-bisphosphate affects the active site.
Formation of ATP by photochemical excitation of benzoquinones in dimethylacetamide solution
Lee, Hung-Wen,Huang, Kunpo
, p. 961 - 963 (2002)
A new method of adenosine triphosphate production is described which involves photo-excitation of p-benzoquinones under the presence of adenosine diphosphate and inorganic phosphate in N,N-dimethylacetamide solution. A possible mechanism for the reaction is presented.
Physiological and biochemical characterization of three nucleoside diphosphate kinase isozymes from rice (Oryza sativa L.)
Kihara, Akihiko,Saburi, Wataru,Wakuta, Shinji,Kim, Myung-Hee,Hamada, Shigeki,Ito, Hiroyuki,Imai, Ryozo,Matsui, Hirokazu
, p. 1740 - 1745 (2011)
Nucleoside diphosphate kinase (NDPK) is a ubiquitous enzyme that catalyzes the transfer of the γ-phosphoryl group from a nucleoside triphosphate to a nucleoside diphosphate. In this study, we examined the subcellular localization, tissue-specific gene expression, and enzymatic characteristics of three rice NDPK isozymes (OsNDPK1-OsNDPK3). Sequence comparison of the three OsNDPKs suggested differential subcellular localization. Transient expression of green fluorescence protein-fused proteins in onion cells indicated that OsNDPK2 and OsNDPK3 are localized to plastid and mitochondria respectively, while OsNDPK1 is localized to the cytosol. Expression analysis indicated that all the OsNDPKs are expressed in the leaf, leaf sheath, and immature seeds, except for OsNDPK1, in the leaf sheath. Recombinant OsNDPK2 and OsNDPK3 showed lower optimum pH and higher stability under acidic pH than OsNDPK1. In ATP formation, all the OsNDPKs displayed lower Km values for the second substrate, ADP, than for the first substrate, NTP, and showed lowest and highest K m values for GTP and CTP respectively.
Biomimetic One-Pot Synthesis of Nucleotide Phosphates
Tabushi, Iwao,Imuta, Jun-ichi
, p. 5415 - 5418 (1982)
A strongly hydrophobic rigid diammonium, 1, an efficient extracting and transporting phase transfer reagent with high specificity for the pyrophosphate grouping, was used to synthesize ADP, ATP or ADP-NH2 in a hydrophobic medium.Thus, practically pure ADP-NH2 was obtained in 65 percent yield within 2 min.
Functional analysis, overexpression, and kinetic characterization of pyruvate kinase from methicillin-resistant staphylococcus aureus
Zoraghi, Roya,See, Raymond H.,Gong, Huansheng,Lian, Tian,Swayze, Rick,Finlay, B. Brett,Brunham, Robert C.,McMaster, William R.,Reiner, Neil E.
, p. 7733 - 7747 (2010)
Novel antimicrobial targets are urgently needed to overcome rising antibiotic resistance of important human pathogens including methicillin-resistant Staphylococcus aureus (MRSA). Here we report the essentiality and kinetic properties of MRSA pyruvate kinase (PK). Targetron-mediated gene disruption demonstrated PK is essential for S. aureus growth and survival, suggesting that this protein may be a potential drug target. The presence of the pfk (6-phosphofructokinase)-pyk operon in MRSA252, and the nonessential nature of PFK shown by targetron, further emphasized the essential role of PK in cell viability. The importance of PK in bacterial growth was confirmed by showing that its enzymatic activity peaked during the logarithmic phase of S. aureus growth. PK from Staphylococcus and several other species of bacteria have an extra C-terminal domain (CT) containing a phosphoenolpyruvate (PEP) binding motif. To elucidate the possible structure and function of this sequence, the quaternary structures and kinetic properties of the full-length MRSA PK and truncated MRSA PK lacking the CT domain were characterized. Our results showed that (1) MRSA PK is an allosteric enzyme with homotetramer architecture activated by AMP or ribose 5-phosphate (R5P), but not by fructose 1,6-bisphosphate (FBP), which suggests a different mode of allosteric regulation when compared with human isozymes, (2) the CT domain is not required for the tetramerization of the enzyme; homotetramerization occurred in a truncated PK lacking the domain, (3) truncated enzyme exhibited high affinity toward both PEP and ADP and exhibited hyperbolic kinetics toward PEP in the presence of activators (AMP and R5P) consistent with kinetic properties of full-length enzyme, indicating that the CT domain is not required for substrate binding or allosteric regulation observed in the holoenzyme, (4) the kinetic efficiency (kcat/S0.5) of truncated enzyme was decreased by 24- and 16-fold, in ligand-free state, toward PEP and ADP, respectively, but was restored by 3-fold in AMP-bound state, suggesting that the sequence containing the CT domain (Gly473-Leu585) plays a substantial role in enzyme activity and comformational stability, and (5) full-length MRSA PK activity was stimulated at low concentrations of ATP (e.g., 1 mM) and inhibited by inorganic phosphate and high concentrations of FBP (10 mM) and ATP (e.g., >2.5 mM), whereas for truncated enzyme, stimulation at low concentrations of ATP was lost. These findings suggest that the CT domain is involved in maintaining the specificity of allosteric regulation of MRSA PK by AMP, R5P, and ATP. The CT extension also encodes a protein domain with homology to enzyme I of the Escherichia coli sugar-PTS system, suggesting that MRSA PK may also exert an important regulatory role in sugar transport metabolism. These findings yield new insights into MRSA PK function and mode of allosteric regulation which may aid in the development of clinically important drugs targeting this enzyme and further define the role of the extra C-terminal domain in modulating the enzyme's activity.
STOICHIOMETRY OF PROTON TRANSLOCATION DURING PHOTOSYNTHESIS.
Rathenow,Rumberg
, p. 1059 - 1062 (1980)
Formation of ATP in photosynthesis takes place at the expense of free energy stored in the gradient of protons across the thylakoid membrane. Set up of the proton gradient is accomplished by the light-driven electron transport reactions. The stoichiometry of H** plus translocation across the thylakoid membrane is determined with respect to electron flow and ATP synthesis. Direct information is obtained on the basis of the H** plus flux measurement. Depending on the experimental conditions two or three H** plus are translocated from outside into the aqueous inner phase of the thylakoid vesicles for each electron which is transfered through the electron transport chain. Three H** plus are translocated from inside to outside across the ATPase for each ATP molecule which is synthesized. Mechanistic and energetic consequences are discussed.
