Thermal Inactivation and Conformational Lock of Bovine Carbonic Anhydrase

Abstract

The kinetics of thermal inactivation of bovine carbonic anhydrase (BCA) was studied in a 50 mM Tris-HCl buffer, pH 7.8 using p-nitrophenyl acetate as substrate in absorbance of 400 nm by UV-VIS spectrophotometry. The number of conformational locks and inter-subunit amino acid residues of BCA were obtained by thermal inactivation analysis. The cleavage bonds between dimers of BCA during thermal dissociation and type of interactions between specific amino acid residues were also detected. The thermal inactivation curves were plotted in temperatures ranging between 40-70°C. It was shown several phases for inactivation of BCA at 65°C. Analyses of the curves were done by the conformational lock theory. The subunits are dissociated and several intermediates appear during inactivation through increasing the temperature in comparison with native state. Dynamic light scattering measurements was done to study the changes in hydrodynamic radius during thermal inactivation. Three distinct zones were shown in DLS data. Biochemical computation using ligplot is performed to find the inter-subunit amino acid residues for BCA.

Carbonic Anhydrase Robustness for Use in Nanoscale CO2 Capture Technologies

“…BCA, in either water or Tris buffer, maintained 79% of its initial activity when kept at 4 °C for 7 days, which contrasts with the complete loss of activity observed at Days 3 and 7 when maintained at 70 °C (Figure ). This observation is consistent with prior reports suggesting that BCA activity is lost at temperatures exceeding 60 °C. , It should be noted that the percent of remaining activity exceeded 100% in some cases and may be attributed to the intrinsic variation in the esterase activity.…”

Xueshuan Xinmaining Tablet Treats Blood Stasis through Regulating the Expression of F13a1, Car1, and Tbxa2r

“…Carbonic anhydrases are zinc metalloenzymes that catalyze the reversible hydration-dehydration of carbon dioxide and bicarbonate [ 37 ]. Cars appear to play a role in diverse physiological and biological processes including respiration, acid-base balance, ion transport, bone absorption, renal acidification, gluconeogenesis, and ureagenesis and in the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid [ 38 ].…”

Extremophilic behavior of catalytic amyloids sustained by backbone structuring

“…Bovine carbonic anhydrase (bCA II) maintains optimum activity at 60 1C, while variants isolated from thermophilic bacteria display optimum activity at up to 80 1C. 40,41 Our measurement of T opt at 81 1C places de novo designed peptides at the extreme of naturally discovered anhydrases, 33% higher than bCA II. Gain of activity as a function of temperature in catalytic amyloids is similar to those observed in thermophilic CA variants, where amyloids exhibit a ten-fold enhancement at T opt over room temperature compared to 6-7 fold enhancements for bCA II.…”