330-13-2Relevant articles and documents
Proton and Cu(II) binding to tren-based tris-macrocycles. Affinity towards nucleic acids and nuclease activity
Bencini, Andrea,Berni, Emanuela,Biancini, Antonio,Giorgi, Claudia,Valtancoli, Barbara,Chand, Dillip Kumar,Schneider, Hans-Joerg
, p. 793 - 800 (2003)
Proton binding by the two tren-based tris-macrocycles L1 and L2, composed, respectively, by three 1,4,7,10-tetrazacyclododecane ([12]aneN4) and three 1-oxa-4,7,10-triazacyclododecane ([12]aneN3O) macrocyclic moieties appended to a "tren" unit (tren = tris(2-aminoethyl)amine), has been analyzed by means of potentiometric and 1H and 13C NMR measurements in aqueous solutions. This study reveals that the ligands form highly charged polyammonium cations at neutral pH, containing six acidic protons equally distributed among the three macrocyclic units. A potentiometric and UV-vis spectrophotometric study shows that both ligands can form stable trinuclear Cu(II) complexes in a wide pH range. In the polynuclear complexes each metal is coordinated to a single macrocyclic unit. While the Cu(II) complexes with L1 do not show any tendency to form hydroxylated complexes, the mono-, di- and trinuclear L2 complexes give stable hydroxo-complexes, present in aqueous solutions from slightly acidic to alkaline pH values. Melting point studies indicate that the new tris-macrocyles and their Cu(II) complexes lead to stronger stabilization of double-stranded nucleic acids than those observed earlier with analogous ditopic macrocyclic ligands, again with preference for RNA-type polymers compared to DNA. The copper complexes promote cleavage of plasmid DNA and of bis-p-nitrophenyl phosphate (BNPP). Particular rate enhancements for BNPP with some complexes are attributed to the simultaneous action of three metal ions and partially to the formation of hydroxo complexes at neutral pH. The Royal Society of Chemistry 2003.
Effect of hydrophobic interaction cooperating with double Lewis acid activation in a zinc(ii) phosphodiesterase mimic
Zhao, Meng,Zhang, Li,Chen, Huo-Yan,Wang, Han-Lu,Ji, Liang-Nian,Mao, Zong-Wan
, p. 6497 - 6499 (2010)
The novel dinuclear Zn(ii) complex (1) containing a β-CD dimer could accelerate BNPP (a DNA substitute) hydrolysis more efficiently than catalyze HPNP (a RNA substitute) transesterification with different mechanisms involved; the β-CDs played remarkably different roles.
An insight into phosphorylase mechanism from model study
Tafesse, Fikru,Eguzozie, Kennedy
, p. 826 - 830 (2010)
Mechanistic aspects of phosphorylation reaction that mimic phosphorylase enzymes have been studied in the biologically important middle pH region by utilizing nitrophenol as substrate and bistrimethylenediaminecobalt(III) phosphate complexes as the enzyme model. Significant phosphorylation was noted from reactions of 1:1 molar ratio of nitrophenol and bistrimethylenediamincobalt(III) phosphate, [Co(III)tn2Pi]. Enhanced phosphorylation was depicted for reaction solutions that contained 1:1 molar ratio of nitrophenol and di-bistrimethylenediamincobalt(III) phosphate, [(Co(III)tn2)2Pi]. Specific mechanistic features and the possible roles metal ions play in phosphorylase enzyme are highlighted. Copyright Taylor & Francis Group, LLC.
Rapid phosphodiester hydrolysis by an ammonium-functionalized copper(II) complex. A model for the cooperativity of metal ions and NH-acidic groups in phosphoryl transfer enzymes
K?vári, Endre,Kr?mer, Roland
, p. 12704 - 12709 (1996)
The copper(II) complexes (L(n))Cu(NO3)4·2(H2O)] (n = 1: 1, n = 2: 2) of the ammonium-functionalized ligands [6,6'-(Me2HNCH2C≡-C)2bpy]2+ (L1) and [6,6'-(Me3NCH2C≡C)2 bpy]2+ L2 were prepared. Hydrolysis of the activated phosphodiester bis(p-nitrophenyl) phosphate (BNPP) by these complexes in ethanol-water 19:1 at 20°C was investigated. The rate constants for cleavage of the bound phosphodiester at pH 6.6 are k(cat) = 4.4(±0.4) x 10-3 s-1 for (L1)Cu and k(cat) = 4(±1) x 10-6 s-1 for (L1)Cu. (L1)CU accelerates hydrolysis of BNPP 4 x 107-fold and is 1000 times more reactive than (L2)Cu. This suggests that the high reactivity of (L1)CU is related to the interaction of the acidic -NMe2H+ group with the phosphodiester substrate. Bifunctional binding of a phosphate ester by metal coordination and hydrogen bonding with one ammonium group is observed in the crystallographically characterized complex [(L1)2Cu2(1,3-μ-O3POPh)2(OH2)2](NO3)4 (3). A plausible mechanism of BNPP cleavage by (L1)CU includes metal-hydroxide attack to the phosphodiester which is doubly activated by coordinative and hydrogen bonding. The copper(II) complex of L1 represents a simple model for the efficient cooperativity of metal ions and NH-acidic amino acid side chains (Lys-ammonium, Arg-guanidinium, His-imidazolium) in enzymes that catalyze the cleavage of phosphate di- and monoesters.
Catalytic zinc complexes for phosphate diester hydrolysis
Tirel, Emmanuel Y.,Bellamy, Zoe,Adams, Harry,Lebrun, Vincent,Duarte, Fernanda,Williams, Nicholas H.
, p. 8246 - 8250 (2014)
Creating efficient artificial catalysts that can compete with biocatalysis has been an enduring challenge which has yet to be met. Reported herein is the synthesis and characterization of a series of zinc complexes designed to catalyze the hydrolysis of phosphate diesters. By introducing a hydrated aldehyde into the ligand we achieve turnover for DNA-like substrates which, combined with ligand methylation, increases reactivity by two orders of magnitude. In contrast to current orthodoxy and mechanistic explanations, we propose a mechanism where the nucleophile is not coordinated to the metal ion, but involves a tautomer with a more effective Lewis acid and more reactive nucleophile. This data suggests a new strategy for creating more efficient metal ion based catalysts, and highlights a possible mode of action for metalloenzymes.
P-nitrophenyl phosphate disodium and preparation method thereof
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Paragraph 0062; 0075-0079; 0084; 0089; 0090, (2020/01/12)
The invention provides p-nitrophenyl phosphate disodium and a preparation method thereof. The preparation method comprises the following steps: 1, enabling p-nitrophenol to react with dialkyl chloridephosphate in the presence of an alkali so as to obtain O,O-dialkyl p-nitrophenyl phosphate; 2, performing an alkyl ester desorption reaction on the O,O-dialkyl p-nitrophenyl phosphate and a compoundwith trimethylsilyl groups so as to obtain O,O-di(trimethylsilyl) p-nitrophenyl phosphate; 3, performing a hydrolysis reaction on the O,O-di(trimethylsilyl) p-nitrophenyl phosphate so as to obtain p-nitrophenyl phosphate; and 4, enabling the p-nitrophenyl phosphate to react with sodium hydroxide, so as to obtain the p-nitrophenyl phosphate disodium. According to the preparation method provided bythe invention, the intermediate product obtained in the step 1 can be purified through vacuum distillation, and byproducts which are hard to remove are not generated in later operation of ether hydrolysis or pH value adjustment, so that the purification difficulty of the product is greatly reduced; and due to selection of the compound with the trimethylsilyl groups, hydrolysis can be implemented thoroughly, and in addition, the system can be clean.
Carbonate-bridged dinuclear lanthanide(III) complexes of chiral macrocycle
Gerus, Aleksandra,?lepokura, Katarzyna,Lisowski, Jerzy
supporting information, p. 115 - 121 (2019/06/11)
Mononuclear Eu(III) and Dy(III) complexes of the chiral hexaaza macrocycle L, 2(R),7(R),18(R),23(R)-1,8,15,17,24,31-hexaazatricyclo[25.3.1.1.0.0]-dotriaconta-10,12,14,26,28,30-hexaene have been obtained as chloride derivatives (1 and 2, respectively) and
Transition States and Control of Substrate Preference in the Promiscuous Phosphatase PP1
Chu, Yuan,Williams, Nicholas H.,Hengge, Alvan C.
, p. 3923 - 3933 (2017/08/07)
Catalytically promiscuous enzymes are an attractive frontier for biochemistry, because enzyme promiscuities not only plausibly explain enzyme evolution through the mechanism of gene duplication but also could provide an efficient route to changing the catalytic function of proteins by mimicking this evolutionary process. PP1γ is an effectively promiscuous phosphatase for the hydrolysis of both monoanionic and dianionic phosphate ester-based substrates. In addition to its native phosphate monoester substrate, PP1γ catalyzes the hydrolysis of aryl methylphosphonates, fluorophosphate esters, phosphorothioate esters, and phosphodiesters, with second-order rate accelerations that fall within the narrow range of 1011-1013. In contrast to the different transition states in the uncatalyzed hydrolysis reactions of these substrates, PP1γ catalyzes their hydrolysis through similar transition states. PP1γ does not catalyze the hydrolysis of a sulfate ester, which is unexpected. The PP1γ active site is tolerant of variations in the geometry of bound ligands, which permit the effective catalysis even of substrates whose steric requirements may result in perturbations to the positioning of the transferring group, both in the initial enzyme-substrate complex and in the transition state. The conservative mutation of arginine 221 to lysine results in a mutant that is a more effective catalyst toward monoanionic substrates. The surprising conversion of substrate preference lends support to the notion that mutations following gene duplication can result in an altered enzyme with different catalytic capabilities and preferences and may provide a pathway for the evolution of new enzymes.
Characterization of wall teichoic acid degradation by the bacteriophage φ29 appendage protein GP12 using synthetic substrate analogs
Myers, Cullen L.,Ireland, Ronald G.,Garrett, Teresa A.,Brown, Eric D.
, p. 19133 - 19145 (2015/09/08)
Background: The GP12 protein from bacteriophage φ29 is a likely wall teichoic acid hydrolase. Results: GP12 is an efficient catalyst of wall teichoic acid hydrolysis that is influenced by glycosylation of the wall teichioc acid polymer. Conclusion: GP12 m
Binuclear copper(II) complexes 1: Synthesis, characterization and evaluation of a new complex in phosphatase-like activity
Schicke, Olivier,Faure, Bruno,Giorgi, Michel,Simaan, A. Jalila,Réglier, Marius
experimental part, p. 189 - 194 (2012/10/08)
A new binuclear Cu(II) complex derived from a pamoic type ligand has been synthesized and characterized by X-ray crystallography. This complex was checked as catalysts in the hydrolysis of bis(p-nitrophenyl)phosphate. Its catalytic properties were studied
