title: 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.
authors: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
authors: L
authors: L
authors: Alaei
authors: A A
authors: AA
authors: Moosavi-Movahedi
authors: H
authors: H
authors: Hadi
authors: A A
authors: AA
authors: Saboury
authors: F
authors: F
authors: Ahmad
authors: M
authors: M
authors: Amani
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry*; D002417:Cattle; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011487:Protein Conformation; D011489:Protein Denaturation; D013696:Temperature
chemical_list: D000596:Amino Acids; D002256:Carbonic Anhydrases