Catalase, immobilization

E. Horozova, Z. Jordanowa, and V. Bogdanovskaya, Enzymatic and electrochemical reactions of catalase immobilized on carbon materials. Z. Natmforsch. 50, 499-504 (1995). 

E. Horozova, N. Dimcheva, and Z. Jordanova, Adsorption, catalytic and electrochemical activity of catalase immobilized on carbon materials. Z Naturforsch. 52, 639-644 (1997). 

Table 19.2 Enzymatic activity of catalase immobilized within AA-AAc and NIPA-AAc hydrogels...

Fig. 19.9 Time-dependent change of enzymatic activity of catalase immobilized within PNIPA gel by sorption (1) and in aqueous solution (2) at temperature interval 25-40°C...

Stock solution. The concentration of the stock solution was determined by the sodium iodate-thiosulfate titration method. For each determination, a 100.0-ml solution was prepared and placed in a vessel connected to a manometer for measuring the pressure. The vessel was sealed after insertion of a measured piece of catalase-immobilized CoFoam. The reaction of catalase with peroxide produces O2, and an increase in pressure indicates a degradation of the peroxide. Thus, a change in pressure in the vessel is a measure of the reaction rate. Since it is sufficient to show differences in test samples, the ideal gas law was used to convert the pressure into mass. The barometer was calibrated with a gauge traceable to National Institutes of Standards and Technology (NIST) standards. 

Bovine liver -50 Catalase immobilized on multiwall carbon nanotubes glassy-carbon electrode and assayed in phosphate buffer solution at pH 6.5 [41]... 

Figure 31-UV- visible spectra of catalase in PBS (pH 7)phosphate buffer solution(curve a) and Cat-NiO film on ITO electrode(curve b). Reprinted from Biophysical Chemistry, 125, A.Salimi, E. Sharifi, A. NoorBakhash, S. Soltanian, Direct electrochemistry and electrocatalytic activity of catalase immobilized onto electrodeposited nano-scale islands of nickel-oxide, 542, Copyright( 2007), with permission from Elsevier.

Peroxidase oxidation of phenol by catalase immobilized on carbon materials... 

The peroxidase activity of immobilized catalase on the oxidation of phenol has been studied. The immt ilization was carried out from catalase solutions with pH < 3,5 on two kinds of soot differing in the average size of the particles building them up. The effect of the initial concentration of ph iol on the rate of its peroxidase oxidation by catalase immobilized on the soot of finer-graWd structure has been studied. The relationships obtained are described by the equation of Michaelis-Menten. The kinetic parameters (the constant of Michaelis - Km. the maximum reaction rate - V, the rate constant - k and the activation energy - of the process were calculated. It was found that catalase adsorbed on the soot of larger globular particles does not take part in the peroxidase oxidation of phenol. 

In biocatalytic systems, catalase is mainly used in immobilized state. High activity of immobilized catalase was achieved on its sorption immobilization on cellulose [6], on silica gel modified with fatty acids or phospholipids [7] as well as on activated carbon fibres and brics/tissues/ [8]. Biocatalytic activity of catalase immobilized on cellulose was also studied in nonaqueous solvents [9,10]. In [9] it was found that unlike the enzyme dissolved in water-dimethylformamide medium, on the oxidation of o-dianisidine in the presence of dimethylfonnamide the immobilized catalase does not show any peroxidase activity. It was used [10] for working out an organic-phase amperometric biosensor by immobilizing the enzyme in a polymeric film on a glass-carbon surface. 

On the adsorption of catalase from solutions with a concentration ofC = 1x10 Mm citrate buffer with pH = 3. 02, a dissociation of the enzyme to subunits takes place [2,18]. No matter how the catalase dissociation is initiated, the dissociation process is always accompanied by a cotain loss of catalase activity and optic changes - a shift towards the shortwave region [19]. The catalase tetramer dissociation to monomers [17] runs according to scheme E4 o 4E. For dissolved catalase and for catalase immobilized on soot "NORTT" the dq>endence of the initial oxidation rate of phenol on the initial concentration of the substrate was studied (Fig.2), where A is the absotbance corresponding to the current concentration of the substrate (phenol). The obtained relationships are Ascribed by the equation of Nfichaelis-Menten ... 

Figure 3. Lineweaver - Burk plot of peroxidase oxidation of phenol by catalase 1. catalase in solution with concentration C = 1.36x10 M 2. catalase immobilized on NORiT , enzyme amount g = 0.37 mg. Concentration of H2O2 C= 2x10 M Citrate buffer pH = 3.02.

The rate constants (Table 1.) for the peroxidase oxidation of phenol at various tenqreratures were calculated by the kinetic equation for a first order reaction (Fig.4). From the data in Table 1 is seen that on peroxidase oxidation of phenol, the catalase immobilized on "NORIT" soot shows a higher catalytic activity than the catalase in solution. It can be explained first, with the fact that the values in Table 1 are not the values for the specific rate constants, and secondly, as the catalase peroxidase fiuiction is characteristic of its subunits, with the complete or partial dissociation of catalase on its immobilization on "NORIT" soot. In this... 

Figure 4. Relationship InA - t for peroxidase oxidation riienoi by catalase immobilized on NORIT soot. Enzyme amount g = 0.41 mg., temperature 30 °C Citrate buffer pH = 3.02.

Chi the basis of E. values we can make a conclusion about the difhision factors which are some of the most conqilicated points concerning catalysis with immobilized enzymes. The value for the activation energy on peroxidase oxidation of phenol with catalase immobilized on "NORIT" soot is E, =10.95 kJ.mof which is an indication that the process takes place under diSusion regime. The latter means that the enzymatic reaction rate is determined by the mass tranfer of substrate to the surfoce of the carrier particles and its diffiision into the carrier. 

The generation of reactive catalase in its oxidized stage can also be achieved by direct electrochemical oxidation (transfer of electrons from ferric protoporphyrin IX to the electrode). Thus, catalase immobilized on graphite electrodes has been used for the hydrogen peroxide-free oxidation of phenol [168l... 

Catalase, immobilized on Euperglt C Origin bovine liver... 

Yildiz H, Akyilmaz E, Din9kaya E (2004) Catalase immobilization in cellulose acetate beads and determination of its hydrogen peroxide decomposition level by using a catalase biosensor. J Artif Cells Blood Subst Biotechnol 32(3) 443 52 Yu M, de Swaan Arons J, Smit JA (1994). A simple model for estimating protein solubility in aqueous polymer solutions. J Chem Technol Biotechnol 60(4) 413 18... 

Goto, T.E., et al. Enzyme activity of catalase immobilized in Langmuir- Blodgett films of phospholipids. Langmuir,26(13), 11135-11139 (2010)... 

Wan L-S, Ke B-B, Wu J, Xu Z-K. Catalase immobilization on electrospun nanofibers effects of porphyrin pendants and carbon nanotubes. J Phys Chem C 2007 111 14091-7. 

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