Molecular characterization, catalytic, kinetic and thermodynamic properties of protease produced by a mutant of Bacillus cereus-S6-3.

Molecular characterization, catalytic, kinetic and thermodynamic properties of protease produced by a mutant of Bacillus cereus-S6-3. Int J Biol Macromol. 2020 May 30;: Authors: Abdel-Naby MA, El-Wafa WMA, Salim GEM Abstract The proteolytic strain Bacillus cereus-S6-3 was subjected to mutagenic treatments viz. UV irradiations and methyl methane sulfonate (MMS). The obtained mutant strain, B. cereus-S6-3/UM90 showed 1.34 fold over the parent strain. Molecular characterization of proteases from the parent (PP/S6-3) and mutant (PM/UM90) strains indicated that they were consisted of two domains and binds a zinc ion and 4 calcium ions in the active site. Amino acid sequence alignment of PM/UM90 protease showed 19 amino acid residues were substituted compared to that of the wild-type enzyme. However, both proteases contained equal number of aromatic and hydrophobic amino acids. Protease from PM/UM90 showed an effective improvement in thermal properties in terms of reaction temperature, t1/2, the values of kd, activation energy (Ea), and decimal reduction time (D) within the temperature range from 60 to 80 °C. In addition, the kinetic and thermodynamic parameters for substrate hydrolysis (i.e., Km, Vmax, ΔH*, ΔG*, ΔS*, kcat, Vmax/Km, kcat/Km, ΔG*E-T and ΔG*E-S) showed a significant improvement of the catalytic efficiency for PM/UM90 protease. Furthermore, the correlation between thermodynamic properties and the patterns of amino aci...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Tags: Int J Biol Macromol Source Type: research