As mentioned, the site-directed mutations (c.f. Scheme 1b) of engineered P411 enzyme enhances the catalytic turnover of C-H amination by several folds and also provides an enantioselective product. However the rationale for the increased activity and selectivity is not apparent and requires elucidation. As such, we intend to show here how theory complements the directed-evolution experiment by providing the underlying mechanistic principles which drive these effects. For simplicity, we named the P-4 variant as variant 1 while P-4 with additional mutations of A82L, A78V, and F263L as variant 2. Note that variant 1 is less reactive and less enantioselective vis-à-vis variant 2.