• Bulletin of the Korean Chemical Society
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• v.26 no.7
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• pp.1051-1056
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• 2005

The interaction of bovine carbonic anhydrase II with copper ions was studied by isothermal titration microcalorimetry, circular dichroism, UV spectrophotometry and temperature scanning spectrophotometry methods at 27 ${^{\circ}C}$ in Tris buffer solution at pH = 7.5. It was indicated that there are three non-identical different binding sites on carbonic anhydrase for $Cu^{2+}$. The binding of copper ions is exothermic and can induce some minor changes in the secondary and tertiary structure of the enzyme, which does not unfold it, but can result in a decrease in both activity and stability of the enzyme.

• BMB Reports
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• v.40 no.2
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• pp.205-211
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• 2007

The stability curve - a plot of the Gibbs free energy of unfolding versus temperature - is calculated for bovine erythrocyte carbonic anhydrase in 150 mM sodium phosphate (pH = 7.0) from a combination of reversible differential scanning calorimetry measurements and isothermal guanidine hydrochloride titrations. The enzyme possesses two stable folded conformers with the conformational transition occurring at ~30$^{\circ}C$. The methodology yields a stability curve for the complete unfolding of the enzyme below this temperature but only the partial unfolding, to the molten globule state, above it. The transition state thermodynamics for the low- to physiological-temperature conformational change are calculated from slow-scan-rate differential scanning calorimetry measurements where it is found that the free energy barrier for the conversion is 90 kJ/mole and the transition state possesses a substantial unfolding quality. The data therefore suggest that the x-ray structure may differ considerably from the physiological structure and that the two conformers are not readily interconverted.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.11
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• pp.607-612
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• 2017

The effect of carbonic anhydrase on $CO_2$ absorption rates and the heat of reaction were evaluated in various amine solutions for post combustion $CO_2$ capture process. The $CO_2$ absorption rate was analyzed in 30 wt% MEA, AMP, DMEA, MDEA aqueous solutions with and without carbonic anhydrase (250 mg/L) from bovine erythrocyte. $CO_2$ absorption rates were increased in all solutions with carbonic anhydrase. The effect of carbonic anhydrase on absorption rates was more in tertiary amine (DMEA and MDEA) solutions than in primary amine (MEA) and hindered amine (AMP) solutions. The heat of reaction of MEA, DMEA, MDEA aqueous solutions with and without carbonic anhydrase were measured using reaction calorimeter. Carbonic anhydrase decreased the heat of absorption in all solutions. The results suggested that tertiary amines that have the excellent desorption ability were suitable for applying carbonic anhydrase to the post combustion $CO_2$ capture process and the effect of carbonic anhydrase was best in MDEA solution.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.495-499
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• 2010

The biocatalytic capture of $CO_2$, and its precipitationas $CaCO_3$, over bovine carbonic anhydrase (BCA) immobilized on a pore-expanded SBA-15 support was investigated. SBA-15 was synthesized using TMB as a pore expander, and the resulting porous silica was characterized by XRD, BET, IR, and FE-SEM analysis. BCA was immobilized on SBA-15 through various approaches, including covalent attachment (BCA-CA), adsorption (BCA-ADS), and cross-linked enzyme aggregation (BCA-CLEA). The immobilization of BCA on SBA-15 was confirmed by the presence of zinc metal in the EDXS analysis. The effects of pH, temperature, storage stability, and reusability on the biocatalytic performance of BCA were characterized by examining para-nitrophenyl acetate (p-NPA) hydrolysis. The $K_{cat}/K_m$ values for p-NPA hydrolysis were 740.05, 660.62, and $680.11M^{-1}s^{-1}$, respectively, where as $K_{cat}/K_m$ for free BCA was $873.76M^{-1}s^{-1}$. The amount of $CaCO_3$ precipitate was measured quantitatively using anion-selective electrode and was found to be 12.41, 11.82, or 11.28 mg $CaCO_3$/mg for BCA-CLEA, BCA-ADS, or BCA-CA, respectively. The present results indicate that the immobilized BCA-CLEA, BCA-ADS, and BCA-CA are green materials, and are tunable, reusable, and promising biocatalysts for $CO_2$ sequestration.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1496-1502
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• 2006

Skeletal muscle contains slow and fast twitch fibers. These skeletal muscle fibers express type I and type II myosin, respectively, and these myosin isoenzymes have different ATPase activity. The aim of this study was to investigate protein profiles of bovine skeletal muscles by proteomic analysis. Fifty seven spots of distinct proteins were excised and characterized. The expression of sixteen spots was differed in longissimus dorsi muscle with a minimal 2-fold change compared to biceps femoris muscle. The majority of differentially expressed proteins belonged to metabolic regulation-related proteins such as glyceraldehyde 3-phosphate dehydrogenase, triosephosphate isomerase and carbonic anhydrase 3. The real time-PCR assay confirmed an increase or induction of specific genes: RGS12TS isoform, GAPDH, triosephosphate isomerase and carbonic anhydrase. These results suggest that the expression of metabolic proteins is under a specific control system in different bovine skeletal muscle. These observations could have significant implications for understanding the physiological regulation of bovine skeletal muscles.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1083-1088
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• 2012

The breeding value of marbling score in skeletal muscle is an important factor for evaluating beef quality. In the present study, we investigated proteins associated with the breeding value of the marbling score for bovine sirloin to select potential biomarkers to improve meat quality through comparative proteomic analysis. Proteins isolated from muscle were separated by two-dimensional gel electrophoresis. After analyzing images of the stained gel, seven protein spots for the high marbling score group were identified corresponding to changes in expression that were at least two-fold compared to the low marbling score group. Four spots with increased intensities in the high marbling score group were identified as phosphoglycerate kinase 1, triosephophate isomerase, acidic ribosomal phosphoprotein PO, and capping protein (actin filament) Z-line alpha 2. Spots with decreased intensities in the high marbling score group compared to the low score group were identified as 14-3-3 epsilon, carbonic anhydrase II, and myosin light chain 1. Expression of myosin light chain 1 and carbonic anhydrase 2 was confirmed by Western blotting. Taken together, these data could help improve the economic performance of cattle and provide useful information about the underlying the function of bovine skeletal muscle.

• KSBB Journal
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• v.28 no.4
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• pp.225-229
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• 2013

Bovine Carbonic anhydrase (BCA) was immobilized on a submicro-porous membrane through covalent immobilization. The immobilization was conducted on the porous membrane surface with the treatment of polyethyleneimine, glutaraldehyde, and the anhydrase, in sequence. The immobilization was confirmed using X-ray photon spectrometer. The pH values of carbon-dioxide saturated solution with buffer were monitored with respect to time to calculate the catalytic activities of hydration of carbon-dioxide for free and immobilized CA. The catalytic rate constant values for free CA, immobilized CA on polystyrene nanoparticles, and immobilized CA on a porous cellulose acetate membrane were 0.79, 0.67, and 0.56 $s^{-1}$, respectively. Reusability was studied up to 10 cycles of $CO_2$ sequestration. The activity for the CA immobilized on the membrane was kept to 95% after 10 cycles, and comparable to the CA on the nanoparticles. The stabilities for heat and storage were also investigated for the three cases. The results suggested that the CA immobilized the membrane had the least loss rate of the activity compared to the others. From this study, the porous membrane was feasible as a carrier for the CA immobilization in hydration and sequestration of carbon-dioxide.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.709-714
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• 2014

Protein tyrosine nitration is considered as an important indicator of nitrosative stresses and as one of the main factors for pathogenesis of inflammation and neuronal degeneration. In this study, we investigated various nitrosative modifications of bovine carbonic anhydrase II (CAII) through qualitative and semi-quantitative analysis using the combined strategy of Fourier transformation ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion-trap tandem mass spectrometry (IT-MS/MS). FT-ICR MS and its spectra were used for the search of the pattern of nitrosative modifications. Identification of nitrosatively modified tyrosine sites were executed through IT-MS/MS. In addition, we also tried to infer the reason for the site-specific nitrosative modifications in CAII. In view of the above purpose, we have explored- i) the side chain accessibility, ii) the electrostatic environment originated from the acidic/basic amino acid residues neighboring to the nitrosatively modified site and iii) the existence of competing amino acid residues for nitration.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3233-3240
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• 2012

We demonstrated the combined applications of online protein digestion using trypsin immobilized enzyme reactor (IMER) and dual tandem mass spectrometry with collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) for tryptic peptides eluted through the trypsin-IMER. For the trypsin-IMER, the organic and inorganic hybrid monolithic material was used. By employing the trypsin-IMER, the long digestion time could be saved with little or no sacrifice of the digestion efficiency, which was demonstrated for standard protein samples. For three model proteins (cytochrome c, carbonic anhydrase, and bovine serum albumin), the tryptic peptides digested by the IMER were analyzed using LC-MS/MS with the dual application of CAD and ETD. As previously shown by others, the dual application of CAD and ETD increased the sequence coverage in comparison with CAD application only. In particular, ETD was very useful for the analysis of highly-protontated peptide cations, e.g., ${\geq}3+$. The combination approach provided the advantages of both trypsin-IMER and CAD/ETD dual tandem mass spectrometry applications, which are rapid digestion (i.e., 10 min), good digestion efficiency, online coupling of trypsin-IMER and liquid chromatography, and high sequence coverage.