Studies on Urate Oxidase of Candida utilis

Some physical and chemical properties of urate oxidase (EC 1.7.3.3) isolated from the cells of Candida utilis were investigated. The molecular weight was estimated to be 1.2 × 10⁵ by the equilibrium sedimentation and gel filtration methods. The isoelectric point was determined as 5.4 by the method of density electrofocusing. The enzyme showed a slight absorption at 410 mμ, and the absorbancy at this wave length was only 3% of that at 280 mμ. Contrary to urate oxidase from swine liver, the enzyme from yeast contained a negligible amount of copper, but it contained iron of nearly one atom per mole of the enzyme protein. The yeast urate oxidase was not inactivated by some chelators. However, it was easily inactivated with certain heavy metal ions such as Hg²⁺, and the inactivated enzyme was reactivated by the addition of thiols, indicating that the enzyme is a sulfhydryl enzyme. The inactivation of the enzyme with urea, on the other hand, was greatly accelerated by the addition of thiols, and some discussion was added to the results obtained.     

Reduced anion binding and anion inhibition in Cu,Zn superoxide dismutase chemically modified at lysines without alteration of the rhombic distortion of the copper site

The spectroscopic binding constant (visible absorption and EPR spectra) and the catalytic inhibition constant of N₃^? and CN^? were measured for bovine Cu, Zn superoxide dismutase chemically modified at all lysines by either succinylation or carbamoylation. These modifications partially inactivate the enzyme (10% and 50% residual activity respectively) but leave the native rhombic geometry of the copper site unaffected. It could thus be shown that the observed reduction of anion affinity of the lysines-modified proteins is related to the decreased positive charge of the protein.     

A study of the sulfhydryl groups of rat brain hexokinase

Rat brain hexokinase (ATP: d-hexose-6-phosphotransferase, EC 2.7.1.1) is rapidly inactivated by reaction with 5,5′-dithiobis-(2-nitrobenzoate). The inactivation follows monophasic first-order kinetics in either the absence of ligands (k = 0.641 min^?1 at 25 °C) or in the presence of saturating levels of ATP (free or complexed with Mg²⁺) or P₁; the inactivation rate is slightly increased ($\text{k ? 0.7}$ min ^?1) in the presence of ATP or P₁. In contrast, glucose and glucose-6-P markedly decrease the inactivation rate; inactivation in the presence of these ligands is biphasic, with two first-order rates ($\text{k ? 0.5}$ min^?1 and 0.01 min^?1) being distinguishable.The enzyme contains 14 sulfhydryl groups which react with 5,5′-dithiobis-(2-nitrobenzoate); reaction of these groups in the native enzyme is complete after 2 hr at 25 °C, or in approx 5 min with the urea or guanidine-denatured enzyme. In the native enzyme, three classes of sulfhydryl groups are distinguishable and are designated as F-, I-, or S-type based on their fast (k ? 0.7 min^?1), intermediate ($\text{k ? 0.5-0.7}$ min^?1), or slow ($\text{k ? 0.02}$ min^?1 rates of reaction with 5,5′-dithiobis-(2-nitrobenzoate). The correlation of inactivation rates with the rates for reaction of the I-type sulfhydryls indicates that the I-type sulfhydryls include residues necessary for catalytic activity. The F-type residues are clearly not required for activity.The effects of ATP, P₁, glucose, and glucose-6-P on the reactivity of the sulfhydryls have been determined. As in the absence of ligands, S-, I-, and F-type sulfhydryls could be distinguished. In the presence of saturating concentrations of these ligands, the F, I, and S classes of sulfhydryls contained respectively: with ATP, 1, 4, and 7 residues; with P₁, 1, 3, and 7 residues; with glucose, 1, 2, and 5 residues; with glucose-6-P, 1, 2, and 1 residues. Comparison with rate constants for inactivation in the presence of these ligands again indicated that I-type sulfhydryls were particularly important in maintenance of enzyme activity. The present results indicate considerable similarity between the reactivity of the sulfhydryl residues in rat brain hexokinase and the sulfhydryls of the bovine brain enzyme [V. D. Redkar and U. W. Kenkare (1972), J. Biol. Chem., 247, 7576–7584].     

Escherichia coli phosphoenolpyruvate carboxylase: kinetics and mechanism of inactivation

In dilute solution phosphoenolpyruvate carboxylase of Escherichia coli undergoes a spontaneous inactivation that can be described mathematically by a two-component declining exponential equation. The rate constant for the decay of the first component is 3.05 ± 0.52 × 10^?2 min^?, whereas that for the second component is variable, smaller in magnitude, and dependent upon the dilution conditions. Analysis of the coefficients for the exponential equation suggests that the decline of enzymatic activity with time is a function of the initial concentrations of catalytically active dimer and tetramer. From the concentrations of these two species, as determined from their initial activities, an equilibrium constant of 3 × 10^?7m for the tetramer-dimer dissociation was determined.The diluted enzyme exhibits properties similar to those ascribed to hysteretic enzymes. The appearance of hysteresis is a function of the time after dilution and the presence of modifiers of catalytic activity, i.e., it is not present immediately after dilution and can be prevented from occurring if aspartate is present in the dilution buffer. The data are consistent with a scheme in which dimeric and tetrameric forms of the enzyme undergo inactivation by dissociation to monomers. The tetramer can dissociate directly to monomers and become inactivated or it can dissociate first to dimers than to monomers before undergoing inactivation. Monomer-to-dimer reassociation occurs to form a catalytically active species, but monomer-to-tetramer reassociation to an active species is not apparent. Hysteresis is presumed to result from reversible isomerization of the monomeric species to a form that can also result in an irreversibly inactivated enzyme.     

A highly stable Cu/Zn superoxide dismutase from <Emphasis Type="Italic">Withania somnifera</Emphasis> plant: gene cloning,expression and characterization of the recombinant protein

A gene from Withania somnifera (winter cherry), encoding a highly stable chloroplastic Cu/Zn superoxide dismutase (SOD), was cloned and expressed in Escherichia coli. The recombinant enzyme (specific activity of ~4,200 U mg⁻¹) was purified and characterized. It retained ~90 and ~70% residual activities after 1 h at 80 and 95°C, respectively. At 95°C, thermal inactivation rate constant (K _d) of the enzyme was 2.46 × 10⁻³ min⁻¹ and half-life of heat inactivation was 4.68 h. The enzyme was stable against a broad pH range (2.5–11.0). It also showed a high degree of resistance to detergent, ethanol and protease digestion. This recombinant Cu/Zn SOD could therefore have useful applications.     

The effect of pH on the structure and activity of yeast RNA polymerase I

The analysis of the effect of pH upon the rate of polymerization indicates that the activity of yeast RNA polymerase I is optimal between pH 7.5 and 9 and depends on the ionization state of two groups with apparent pK_a values of 6.5 and 10. Yeast RNA polymerase I is extremely labile at acid pH. Below pH 5 the enzyme is irreversibly inactivated by [H⁺], with a second-order rate constant of 1.6 × 10^?4m^?1 min^?1. Sucrose gradient sedimentation and gel electrophoresis analysis of the enzyme inactivated at acid pH indicates the sequential dissociation of several enzyme subunits. The polypeptides of 44,000 and 24,000 daltons dissociate first from the enzyme core followed by the dissociation of the polypeptides of 48,000 and 36,000 daltons.     

Esteroproteolytic enzymes from the submaxillary gland. Kinetics and other physicochemical properties.

Two esteroproteolytic enzymes (A and D) have been isolated from the mouse submaxillary gland and shown to be pure by ultracentrifugation, immunoelectrophoresis, acrylamide-gel electrophoresis, and amino acid analyses. The enzymes have molecular weights of approximately 30,000 and are structurally and antigenically related. Narrow pH optima between 7.5 and 8.0 are exhibited by both enzymes. The “pK₁'s” are between 6.0 and 6.5 and the “pK₂'s” are near 9.0. A marked preference for arginine-containing esters is shown by both enzymes. The maximum specific activity of enzyme A on p-tosylarginine methyl ester (TAME) at pH 8 was 2500–3000 μm min^?1 mg^?1 and for enzyme D, 400–600 μm min^?1 mg^?1. With TAME as substrate, the K_m for enzyme A was 8 × 10^?4m at 25 °C and 6 × 10^?4m at 37 °C. For D, K_m was 3 × 10^?4 at 25 °C and 2 × 10^?4m at 37 °C.An apparent activation of enzyme D by tosylarginine (TA), a product of TAME hydrolysis, and all α-amino acids examined was due to removal of an inhibitor by chelation. This effect could be duplicated by 8-hydroxyquinoline and diethyldithiocarbamate but not by EDTA. Enzyme A was not affected by these substances to any remarkable extent. Several divalent ions proved to be potent inhibitors of enzyme D. Both enzymes are inactivated by the active site reagents diisopropyl phosphofluoridate and tosyllysine chloromethylketone but much less rapidly than is trypsin. Nitrophenyl-4-guanidionobenzoate reacts with a burst of nitrophenol liberation but with a rapid continuing hydrolysis. One active site per molecule is indicated. Enzyme D is inactivated by urea, reversibly at 10 m and with maximal permanent losses at 6 m. Autolysis of the unfolded form by the native enzyme when they coexist at intermediate urea concentrations appears to occur.Identity of enzyme D and the epithelial growth factor binding protein is demonstrated.     

Irreversible inhibition of phosphorylase phosphatase by fluorophosphate.

The inactivation of phosphorylase phosphatase by fluorophosphate is described. The inactivation is dependent upon time and concentration of fluorophosphate and cannot be reversed by removal of fluorophosphate from the enzyme. Acid hydrolysis of fluorophosphate destroys the capacity for inhibition. The inactivation exhibits saturation kinetics. A dissociation constant for the enzyme-fluorophosphate complex and a rate constant for the reaction were calculated to be 5.5 × 10^?3 M and 0.22 min^?1, respectively. A competitive inhibitor, phosphate, protects the enzyme against inactivation. The data are consistent with an irreversible covalent modification of the active site of phosphorylase phosphatase by fluorophosphate.     

Purification and characterization of selenium-glutathione peroxidase from hamster liver

Hamster liver glutathione peroxidase was purified to homogeneity in three chromatographic steps and with 30% yield. The purified enzyme had a specific activity of approximately 500 μmol cumene hydroperoxide reduced/min/mg of protein at 37 °C, pH 7.6, and 0.25 mm GSH. The enzyme was shown to be a tetramer of indistinguishable subunits, the molecular weight of which was approximately 23,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A single isoelectric point of 5.0 was attributed to the active enzyme. Amino acid analysis determined that selenocysteine, identified as its carboxymethyl derivative, was the only form of selenium. One residue of cysteine was found to be present in each glutathione peroxidase subunit. The presence of tryptophan was colorimetrically determined. Pseudo-first-order kinetics of inactivation of the enzyme by iodoacetate was observed at neutral pH with GSH as the only reducing agent. An optimal pH of 8.0 at 37 °C and an activation energy of 3 kcal/mol at pH 7.6 were found. A ter-uni-ping-pong mechanism was shown by the use of an integrated-rate equation. At pH 7.6, the apparent second-order rate constants for reaction of glutathione peroxidase with hydroperoxides were as follows: k₁ (t-butyl hydroperoxide), 7.06 × 10⁵ mm min^?1; k₁ (cumene hydroperoxide), 1.04 × 10⁶ mm^?1 min^?1; k₁ (p-menthane hydroperoxide), 1.2 × 10⁶ mm^?1 min^?1; k₁ (diisopropylbenzene hydroperoxide), 1.7 × 10⁶ mm^?1 min^?1; k₁ (linoleic acid hydroperoxide), 2.36 × 10⁶ mm^?1 min^?1; k₁ (ethyl hydroperoxide), 2.5 × 10⁶ mm^?1 min^?1; and k₁ (hydrogen peroxide), 2.98 × 10⁶ mm^?1 min^?1. It is concluded that for bulky hydroperoxides, the more hydrophobic the substrate, the faster its reduction by glutathione peroxidase.     

The low-molecular-weight acid phosphatase from bovine liver: Isolation,amino acid composition,and chemical modification studies

The smallest of the three molecular weight forms of acid phosphatase from bovine liver was purified to a specific activity of 100 μmol min^?1 mg^?1 (measured at pH 5.5 and 37 °C with p-nitrophenyl phosphate). Using several chromatographie and electrophoretic methods, no evidence of heterogeneity was detected. The enzyme was characterized with respect to its stability as a function of pH, molecular weight, amino acid composition, steady-state kinetic parameters in the pH range 4–7 and inhibition by common acid phosphatase inhibitors at pH 5.5. The amino acid composition differed somewhat from a previous literature report. The enzyme was stoichiometrically inactivated upon incubation with Hg²⁺, Ag⁺, and iodoacetate. Inactivation also occurred upon photoinactivation in the presence of Rose Bengal but no inactivation occurred with diethyl pyrocarbonate. The alkylation of one of five cysteine residues by iodoacetate was shown to cause complete inactivation of the enzyme. This alkylation was prevented by the presence of phosphate ion. A tryptic dipeptide containing this essential cysteine was isolated following inactivation with iodo[2-¹⁴C]acetate.     

Inactivation of E. coli RNA polymerase by pyridoxal 5'-phosphate: identificationof a low pKa lysine as the modified residue.

The inactivation of E. coli RNA polymerase (3.3 × 10^?7M) by pyridoxal 5′-phosphate (1 × 10^?4M to 5 × 10^?4M) is a first order process with respect to the remaining active enzyme. Studies of the variation of the first order rate constant with the concentration of pyridoxal 5′-phosphate show that the inactivation reaction follows saturation kinetics. The formation of a reversible enzyme-inhibitor intermediate is postulated. Kinetic studies at different pH values indicate that the inactivation rate constant depends on the mole fraction of one conjugate base with pK_a 7.9. The apparent equilibrium constant (association) for the inactivation reaction is independent of the pH and is 1.8 × 10⁴ M^?1. By electrophoretic and chromatographic analysis of enzyme hydrolyzates after pyridoxal 5′-phosphate and NaBH₄ treatment only N-ε-pyridoxyllysine was found. It is postulated that a lysine ε-amino group with a low pK_a is critical for the activity of the enzyme.     

Molecular and catalytic properties of the acetoacetyl-coenzyme A thiolase of Escherichia coli.

The acetoacetyl-CoA-thiolase, a product of the acetoacetate degradation operon (ato) was purified to homogeneity as judged by polyacrylamide-gel electrophoresis at pH 4.5, 7.0, and 8.3. The enzyme has a molecular weight of 166,000 and is composed of four identical subunits. The subunit molecular weight is 41,500. Histidine was the sole N-terminal amino acid detected by dansylation. The thiolase contains eight free sulhydryl residues and four intrachain disulfide bonds per mole. The ato thiolase catalyzes the CoA- dependent cleavage of acetoacetyl-CoA and the acetylation of acetyl-CoA to form acetoacetyl-CoA. The maximal velocity in the direction of acetoacetyl-CoA cleavage was 840 nmol min^? (enzyme unit)^?1 and the maximal velocity in the direction of acetoacetyl CoA formation was 38 nmol min^?1 (enzyme unit)^?1. Like other thiolases, the ato thiolase was inactivated by sulfhydryl reagents. The enzyme was protected from inactivation by sulfhydryl reagents in the presence of the acyl-CoA substrates, acetyl-CoA and acetoacetyl-CoA; however, no protection was obtained when the enzyme was incubated with the acetyl-CoA analog, acetylaminodesthio-CoA. Consistent with these results was the demonstration of an acetyl-enzyme compound when the thiolase was incubated with [1-¹⁴C]acetyl-CoA. The sensitivity of the acetyl-enzyme bond to borohydride reduction and the protection afforded by acyl-CoA substrates against enzyme inactivation by sulfhydryl reagents indicated that acetyl groups are bound to the enzyme by a thiolester bond.     

ADSORPTION AND UPTAKE OF COPPER BY THE GREEN ALGA SCENEDESMUS SUBSPICATUS (CHLOROPHYTA)1

Copper (II) accumulation has been investigated in the green alga Scenedesmus subspicatus G. Brinkmann considering both adsorption and uptake kinetics. Experiments were conducted in a Cu- and PH-buffered medium at different free Cu²⁺ concentrations that were neither growth limiting nor toxic. We distinguished between adsorption on the cell surface and intracellular uptake by extracting copper from the cells with EDTA. Data from short-term experiments were compared with data obtained from experiments under steady state conditions. The accumulation of Cu can be described by two processes, an initial fast adsorption occurring within a minute followed by a slower intracellular uptake. Metal uptake followed Michaelis-Menten kinetics and is mediated by two systems, one with low and the other with high affinity. The maximum uptake rates (1.30 × 10^?-¹⁰ mol·[g dry wt algae]^?1· min^?1, 3.67 × 10^?-⁹ mol·[g dry wt algae]^?1·min^?1), and the half-saturation constants (6.84 × 10^?-¹⁴ M, 2.82 × 10^?-¹² M) for the two uptake systems were determined using the Lineweaver-Burk plot. The calculated maximum concentration of binding sites on the surface of the algae is initially higher (9.0 × 10^?-⁶ mol Cu.[g dry wt algae]^?1) than under steady state conditions (2.9 × 10^?-⁶ mol Cu·[g dry wt algae]^?1). This suggests that the initial binding to the algal surface comprises the binding to specific transport ligands as well as to inert adsorption sites. The conditional stability constant of the Cu binding to surface ligands was calculated as log K_Cu= 11.0 at pH 7.9. This freshwater alga has a high ability to accumulate Cu, reflecting its adaptation to the bioavailable concentration of copper.     

Agaricus bisporus metapotyrosinase: preparation, characterization, and conversion to mixed-metal derivatives of the binuclear site

The alpha, beta, and gamma isozymes of Agaricus bisporus tyrosinase undergo inactivation in the presence of oxalate. The inactivation rate law is first order in enzyme and second order in oxalate. On a more rapid time scale than inactivation, oxalate acts as a competitive inhibitor of the catecholase reaction of tyrosinase. After removal of oxalate by dialysis, the inactivated enzyme is found to contain 50% of the original copper, all of which is present as paramagnetic, mononuclear copper sites. The ESR parameters of this copper indicate a tetragonal environment with nitrogen and oxygen ligands. The product of oxalate inactivation has lost one copper from each binuclear site and is thus a metapo derivative. Addition of Cu(II) to metapotyrosinase results in complete recovery of copper and catalytic activity. Prolonged storage of metapotyrosinase, in the absence of any additional Cu(II), results in copper migration, producing a 50% recovery of the original specific activity, expressed on a protein basis. Copper migration converts metapo sites into equal numbers of reconstituted, holo sites and fully apo sites. Both copper migration and copper reconstitution follow apparent first-order kinetics and are pH dependent. The involvement of two ionizable groups accounts for the observed pH dependence of each process. For copper migration pKa values of 6.0 and 8.8 were found, while for copper reconstitution the pKa values were 5.4 and 6.9. Addition of either Co(II) or Zn(II) to metapotyrosinase results in the formation of enzymatically inactive, mixed-metal derivatives of the binuclear copper site having one Cu(II) and one Co(II) or Zn(II) ion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biomass growth variation and phytoextraction potential of four Salix varieties grown in contaminated soil amended with lime and wood ash

Abstract

In a greenhouse experiment, plant growth and copper (Cu) and zinc (Zn) uptake by four Salix cultivars grown in Cu and Zn contaminated soils collected from a mining area in Finland were tested to assess their suitability for phytoextraction. The cultivars displayed tolerance to heavily contaminated soils throughout the experiment. After uptake, total mean Cu concentrations in the leaves, shoots and roots in all cultivars and treatments ranged from 163 to 474?mg kg^?1 and mean Zn concentrations ranged from 776 to 1823?mg kg^?1. Lime and wood ash addition increased dry biomass growth (25–43%), chlorophyll fluorescence (Fv/Fm) values (3–6%), the translocation factor (TF) (15–60% for Cu; 10–25% for Zn), the bio-concentration factor (BCF) (40–85% for Cu; 70–120% for Zn), and metal uptake (55–70% for Cu; 50–65% for Zn) compared to unamended treatment across all cultivars. The results revealed that Salix cultivars have the potential to take up and accumulate significant amounts of Cu and Zn. Cultivar Klara (Salix viminalis × S. schwerinii × S. dasyclados) was found to be the most effective cultivar for phytoextraction since it displayed greater dry biomass production, Fv/Fm, TF, BCF values and uptake percentage rates of Cu and Zn compared to the other three cultivars. This study indicates that further research is needed to clarify the wider phytoextraction capabilities of different Salix cultivars.     

Irreversible inactivation of urocanase by 4-bromocrotonate.

Urocanase from Pseudomonas putida is irreversibly inactivated by 4-bromocrotonate. At pH 6.7 and 25°, the rate of inactivation is first-order in remaining active enzyme and follows saturation kinetics with a K₁ of 180 mM and a maximum inactivation rate of 0.889 min^?1. The rate constant of inactivation decreases with pH in the pH range 5.8 to 8.5. 4-Bromocrotonate methyl ester inactivates urocanase at only 3% the rate observed with bromocrotonate while other alkylating reagents are ineffective in promoting a time-dependent loss of activity. Dihydrourocanate protects competitively against bromocrotonate inactivation; an average value of 3.3 mM at pH 6.7 is obtained for the enzyme-dihydrourocanate dissociation constant. Protection against inactivation is also offered by fumarate and crotonate, but not by maleate. The results are consistent with bromocrotonate reacting within the active site region of the enzyme.     

The identity of a new copper(II) electron paramagnetic resonance signal in cytochrome c oxidase

In reoxidation experiments with cytochrome c oxidase (EC 1.9.3.1) in the presence of both reducing substrate and molecular oxygen, a new EPR signal from Cu²⁺ has been observed. The new signal corresponds to 0.45 Cu per functional unit. It is concluded that the new EPR signal originates from Cu²⁺_B, the copper which is EPR-nondetectable in the resting enzyme.Optical absorption changes in the 500–700 nm region accompanies the decay of the new Cu²⁺ EPR signal.Based on the results in this investigation a catalytic cycle for cytochrome oxidase is proposed.     

Evidence of essential arginyl residues in rabbit muscle pyruvate kinase.

Rabbit muscle pyruvate kinase is inactivated by 2,3-butanedione in borate buffer. The inactivation follows pseudo-first-order kinetics with a calculated second-order rate constant of 4.6 m^?1 min^?1. The modification can be reversed with almost total recovery of activity by elimination of the butanedione and borate buffer, suggesting that only arginyl groups are modified; this result agrees with the loss of arginine detected by amino acid analysis of the modified enzyme. Using the kinetic data, it was estimated that the reaction of a single butanedione molecule per subunit of the enzyme is enough to completely inactivate the protein. The inactivation is partially prevented by phosphoenolpyruvate in the presence of K⁺ and Mg²⁺, but not by the competitive inhibitors lactate and bicarbonate. These findings point to an essential arginyl residue being located near the phosphate binding site of phosphoenolpyruvate.     

Rapid freeze- and chemical-quench studies of dopamine beta-monooxygenase: comparison of pre-steady-state and steady-state parameters

The copper-containing enzyme dopamine beta-monooxygenase has been studied with regard to pre-steady-state kinetics of tyramine hydroxylation and reduction of enzyme-bound Cu2+ by chemical- and freeze-quench EPR techniques. The bulk of the enzyme-bound copper (approximately 70%) is reduced in a single-exponential process with a limiting rate constant of 250 s-1, Km = 0.9 mM, consistent with participation of both copper ions in the redox events of catalysis. The remaining copper is reduced much more slowly (k approximately 2 s-1) or not at all, attributed to a distribution of copper into inhibitory binding sites and the presence of some inactive enzyme. Knowledge of the Cu2+ reduction rate, together with rate constants calculated from steady-state isotope effects [Miller, S. M., & Klinman, J. P. (1985) Biochemistry 24, 2114-2127], has allowed prediction of pre-steady-state product formation transients. Measurement of these transients under conditions of excess ascorbate shows close agreement with prediction, supporting the validity of individual rate constants obtained from steady-state data. Kinetic modeling shows further that the predominant steady-state enzyme form is the enzyme-product complex (E-P), which is expected to show a correspondingly large (approximately 70% of total copper) EPR signal for bound Cu2+. Surprisingly, the steady state is characterized by a low (19% of total copper) EPR signal. This lack of correlation between the anticipated and observed steady-state EPR signal suggests either antiferromagnetic coupling in binuclear copper centers or reduction of Cu2+ in this enzyme form by ascorbic acid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Synthesis,characterization and nucleic acid binding studies of mononuclear copper(II) complexes derived from azo containing O,O donor ligands

Abstract

Azo linked salicyldehyde and a new 2-hydroxy acetophenone based ligands (HL¹ and HL²) with their copper(II) complexes [Cu(L¹)₂] (1) and [Cu(L²)₂] (2) were synthesized and characterized by spectroscopic methods such as ¹H, 13C NMR, UV–Vis spectroscopy and elemental analyses. Calculation based on Density Functional Theory (DFT), have been performed to obtain optimized structures. Binding studies of these copper (II) complexes with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) were analyzed by absorption spectra, emission spectra and Viscosity studies and Molecular Docking techniques. The absorption spectral study indicated that the copper(II) complexes of 1 and 2 had intrinsic binding constants with DNA or RNA in the range of 7.6?±?0.2?×?10³?M^?1 or 6.5?±?0.3?×?10³M^?1 and 5.7?±?0.4?×?10⁴ M^?1 or 1.8?±?0.5?×?10³ M^?1 respectively. The synthesized compounds and nucleic acids were simulated by molecular docking to explore more details mode of interaction of the complexes and their orientations in the active site of the receptor.