In Silico Based Prediction and Correlation of Dehalogenase Enzyme Activity of Some Haloalkane Compounds by Quantitative Structure Biodegradation Relationship (QSBR) Analysis

The present study deals with correlation of few important molecular features (descriptors) that are responsible for dehalogenation activity. Here, the microbial dehalogenation rate constants for 21 haloalkane compounds were obtained from literature resources. Three types of descriptors viz. constitutional, topological indices were calculated for these compounds using Dragon software and the quantum mechanical descriptors were computed by MOPAC2012 PM7 and RM1 calculation. The correlation values of degradation constants and the descriptors were correlated by the BuildQSAR software tool. When Kcat / Km value was considered as a dependent variable, it well-fitted with a squared correlation coefficient (R²) value of 0.410, 0.497, and 0.819 for selected descriptors under constitutional, topological and quantum chemical (calculated by MOPAC 2012, RM1 module) type respectively. The analysis also showed that, quantum chemical descriptors such as ionization potential, HUMO/SOMO, LUMO energy, dipole moment and carbon-halogen atom distance (lowest) are best correlated features with the biodegradation mechanism of these compounds by the haloalkane dehalogenase enzymes.