In summary, the hydrogen bonds at the interfaces of the Heme-α-helix 8 and PLP-α-helix 8 in hCBS enzyme allow the electron rich cofactors to redistribute electron density among the neighbouring amino acid residues, residing in the α-helix 8. The intra-molecular hydrogen bonds present between amine( -N -H) and carbonyl(C --O) groups of the peptide backbone α-helix 8 facilitate the communication between the hydrogen bond mediated redistributed electron densities at the Heme-α-helix 8 and PLP-α-helix 8 interfaces. The atomic charge density of the electrophilic C4A atom of the PLP-Lys Schiff base, which directly takes part in the enzymatic activity gets depleted due to the electron delocalization. Our study clearly demonstrates α-helix 8, acting as the electron reservoir modulates the electron density at the electrophilic site of the catalytic center PLP via the interfacial hydrogen bonds with the PLP.