Hydrolytic activity of a crown ether-lanthanum complex in the phosphate diester and DNA cleavage

2016 ◽  
Vol 15 (4) ◽  
pp. 315-324 ◽  
Author(s):  
Jiaqing Xie ◽  
Ya Zhang ◽  
Shulan Cai ◽  
Famei Feng
Keyword(s):  
Crown Ether ◽  
Dna Cleavage ◽  
Hydrolytic Activity ◽  
Phosphate Diester ◽  
Lanthanum Complex

Hydrolytic activity of a dinuclear copper(II,II) complex in phosphate diester and DNA cleavage

2002 ◽  
Vol 337 ◽  
pp. 366-370 ◽  
Author(s):  
Liane M. Rossi ◽  
Ademir Neves ◽  
Rosmari Hörner ◽  
Hernán Terenzi ◽  
Bruno Szpoganicz ◽  
...  
Keyword(s):  
Dna Cleavage ◽  
Hydrolytic Activity ◽  
Dinuclear Copper ◽  
Phosphate Diester

Hydrolysis of phosphate diester catalysed by transition metal complexes of a salicylaldimine Schiff base bearing dibenzo-18-crown-6

2005 ◽  
Vol 2005 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Jin Zhang ◽  
Jia-qing Xie ◽  
Ying Tang ◽  
Jun Li ◽  
Jian-zhang Li ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Schiff Base ◽  
Crown Ether ◽  
Transition Metal Complexes ◽  
Catalytic Hydrolysis ◽  
Reaction Conditions ◽  
Reaction Systems ◽  
Phosphate Diester ◽  
Nitrophenyl Phosphate ◽  
Hydrolysis Of

A new crowned Schiff base ligand and its cobalt(II) and manganese(III) complexes were synthesised and characterised. These complexes were used to catalyse the hydrolysis of bis(4-nitrophenyl) phosphate (BNPP) in order to mimic the action of hydrolytic metalloenzymes. The kinetics and the mechanism of the titled reactions were investigated. The change of the characteristic ultraviolet spectra of the reaction systems was also analysed. A kinetic mathematical model of BNPP cleavage catalysed by the complexes is proposed. The function of the crown ether ring and the effects of the reaction conditions on the catalytic hydrolysis of BNPP are discussed.

Hydrolytic Activity of a Neodymium(III) Complex in DNA Cleavage

2014 ◽  
Vol 900 ◽  
pp. 312-315
Author(s):  
Shu Lan Cai ◽  
Fa Mei Feng ◽  
Kang Quan Qiao ◽  
Ying Zhang ◽  
Xiu Lan Zhang
Keyword(s):  
Dna Cleavage ◽  
Double Helix ◽  
Hydrolytic Activity ◽  
Supercoiled Dna ◽  
Phosphodiester Bond ◽  
Supercoiled Form ◽  
Neodymium Complex ◽  
Cutting Effect ◽  
Electrophoresis Method ◽  
Dna Double Helix

A azamacrocyclic compound with carboxyl branch, 5,5,7,12,12,1-hexamethy-1,4 ,8,11-tetraazacyclo- tetradecane-N/-acetic acid(L), and its neodymium complex ware synthesized and characterized. The mode of combination of the neodymium complex with DNA was investigated by UV-vis absorption spectroscopy methods. The cutting function of the neodymium complex to supercoiled DNA was studied by gel electrophoresis method. The results show that metal complex can bind to the phosphate of DNA double helix and promote the hydrolysis of phosphodiester bond of supercoiled DNA(Form I); Supercoiled form DNA was transformed into nicked form DNA(Form II) with strong cutting effect of the macrocyclic neodymium complex; the reaction of DNA cut is completed by a hydrolysis mechanism.

scholarly journals Nuclease Activity of Diaza-Crown Ether Complexes of Cerium(III) with Different Functional Groups as Side Arms

2018 ◽  
Vol 43 (1) ◽  
pp. 91-99
Author(s):  
Bingying Jiang ◽  
Shulan Cai ◽  
Jiaqing Xie ◽  
Fa-Mei Feng
Keyword(s):  
Crown Ether ◽  
Functional Groups ◽  
Dna Cleavage ◽  
Catalytic Mechanism ◽  
Reaction System ◽  
Catalytic Efficiency ◽  
Nuclease Activity ◽  
Activity Difference ◽  
High Concentrations ◽  
The Stability

Cerium(III) complexes of two ligands of a diaza-crown ether with different functional groups as side arms were synthesised and characterised. The catalytic ability of the cerium(III) complexes for pUC19 DNA cleavage was investigated and compared using agarose gel electrophoresis. The results indicate that the catalytic activity of the complex CeL2 [L2 = 2,2′- (1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl) diacetamide] with two carbamoylmethyl groups is significantly higher than the complex CeL1 [L1 = 2,2′- (1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl) diethanol] with two hydroxyethyl groups under the same conditions. The optimum catalytic concentrations of CeL1 and CeL2 were 7.69 × 10−5 and 3.08 × 10−5 mol L−1 respectively and excessively high concentrations of the complexes can reduce their catalytic efficiency due to the formation of inactive μ-hydroxo dimers. The optimum catalytic acidities of CeL1 and CeL2 were pH 7.0 and 7.5 respectively and excessively high pH of the reaction system can reduce the catalytic efficiency of the complexes due to the formation of cerium(III) hydroxide. DNA cleavage promoted by the two complexes takes place via the same hydrolytic pathway and so the activity difference of the two complexes is attributed to the stability of the complexes, rather than the catalytic mechanism.

Transition Metal Complexes of a Diaza-Crown Ether with two Carbamoylmethyl Substituents: Synthesis and Assessment as a Functional Nuclease

2017 ◽  
Vol 42 (2) ◽  
pp. 136-144
Author(s):  
Jia-qing Xie ◽  
Shu-lan Cai ◽  
Fa-mei Feng
Keyword(s):  
Transition Metal ◽  
Crown Ether ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Dna Cleavage ◽  
Catalytic Mechanism ◽  
Active Species ◽  
Lewis Acidity ◽  
Hydrolytic Cleavage ◽  
Central Metal

We report the synthesis, catalytic function and catalytic mechanism of two transition metal complexes (CuL, ZnL) of a diaza-crown ether with two acetylamino side arms [L = 2,2′-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)diacetamide] in the hydrolysis of DNA. Their nuclease functions on pUC19 DNA cleavage were investigated. The results indicated that the active species might be formed by the deprotonation of the water-coordinated molecules in the complex and the optimum pH is 8.0 for both CuL and ZnL. The catalytic activity of CuL is higher than that of ZnL in DNA hydrolytic cleavage due to the difference in the Lewis acidity of the central metal ions, which is contrary to the result with the Cu and Zn complexes of the parent ligand L0 (1,4,10,13-tetraoxa-7,16-diazacyclooctadecane) as artificial nuclease. Comparison studies of DNA cleavage in the presence and absence of several oxygen scavengers showed that these complexes can promote DNA cleavage by a hydrolytic pathway. Our proposed mechanism suggests that the negative charge on the phosphorus oxygen atom of the substrate molecule is dispersed and the intermediate is formed and stabilised by hydrogen bonding between the DNA molecule and the acetylamino group of the complex.

Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

1966 ◽  
Vol 16 (01/02) ◽  
pp. 018-031 ◽  
Author(s):  
S Sherry ◽  
Norma Alkjaersig ◽  
A. P Fletcher
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Comparative Studies ◽  
Esterase Activity ◽  
Methyl Esters ◽  
Hydrolytic Activity ◽  
The Other ◽  
Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

Sign in / Sign up

Export Citation Format

Share Document