## 3 Results and Discussion
### Quantum Chemical Calculations  
3.1 Chemical Reactivity and Charge Transfer Calculations (\(\Delta\)N) for Protein CYP3A4 (1 TQN, 20 VM, 4 NY4, and 1W0E PDB) with AFB1  
Calculated chemical reactivity parameters were used for the determination of the charge transfer parameter (\(\Delta\)N) during the interaction between the protein and ligand. In this analysis, different PDB files for CYP3A4 (1 TQN, 20 VM, 4 NY4, 1W0E) were employed in order to describe the active site and all the residues involved in the interactions with AFB1. These parameters were approximated using [PERSON] theorem as stated in Section 2.4 (see Equations (1)-(5)). They were calculated using the M06/6-311G(d,p) methodology, with the exception of the LANL2 DZ pseudopotential for the Fe atom of the HEM group. Table 5 presents the results for the interaction of AFB1 and the corresponding amino acids of the CYP3A4 protein. In this table are mainly included the amino acids reported for the 1 TQN PDB ID because this calculation showed the highest number of amino acids interacting with the AFB1 aflatoxin. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Resolute**} & \multirow{2}{*}{**PDB**} & \multirow{2}{*}{\begin{tabular}{c} **E\({}_{\text{HOMO}}\)** \\ **(eV)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **E\({}_{\text{LUMO}}\)** \\ **(eV)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Electron** \\ **Affinity** \\ **(eV)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Ionization** \\ **Potential** \\ **(eV)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Hardness** \\ **Potential** \\ **(eV)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Chemical** \\ **Potential** \\ **(eV)** \\ \end{tabular} } \\ \hline \multirow{4}{*}{AFB1} & 1 TQN & \(-\)7.4236 & \(-\)1.1978 & 1.1978 & 7.4236 & 3.1128 & \(-\)4.3107 \\  & 1W0E & \(-\)6.6317 & \(-\)2.0710 & 2.0710 & 6.6317 & 2.2803 & \(-\)4.3514 \\  & 20 VM & \(-\)6.7898 & \(-\)2.1992 & 2.1992 & 6.7898 & 2.2953 & \(-\)4.4945 \\  & 4 NY4 & \(-\)6.5922 & \(-\)2.0506 & 2.0506 & 6.5922 & 2.2708 & \(-\)4.3214 \\ \hline \multirow{4}{*}{ARG105} & 1 TQN & \(-\)7.1661 & \(-\)0.7281 & 0.7281 & 7.1661 & 3.2190 & \(-\)3.9471 \\  & 1W0E & & & & Not present & & \\  & 20 VM & \(-\)7.3185 & \(-\)1.0767 & 1.0767 & 7.3185 & 3.1209 & \(-\)4.1976 \\  & 4 NY4 & & & & Not present & & \\ \hline \multirow{4}{*}{SER119} & 1 TQN & \(-\)7.4236 & \(-\)1.1978 & 1.1978 & 7.4236 & 3.1128 & \(-\)4.3107 \\  & 1W0E & \(-\)7.1000 & \(-\)0.9390 & 0.9390 & 7.1000 & 3.0804 & \(-\)4.0195 \\  & 20 VM & \(-\)7.5033 & \(-\)0.9355 & 0.9355 & 7.5033 & 3.2839 & \(-\)4.2194 \\  & 4 NY4 & & & & Not present & & \\ \hline \multirow{4}{*}{ARG212} & 1 TQN & \(-\)7.6189 & \(-\)0.7007 & 0.7007 & 7.6189 & 3.4591 & \(-\)4.1598 \\  & 1W0E & & & & Not present & & \\  & 20 VM & & & & Not present & & \\  & 4 NY4 & \(-\)7.5411 & \(-\)0.8419 & 0.8419 & 7.5411 & 3.3496 & \(-\)4.1915 \\ \hline \multirow{4}{*}{ARG212-PHE213} & 1 TQN & \(-\)7.2195 & \(-\)1.0068 & 1.0068 & 7.2195 & 3.1063 & \(-\)4.1131 \\  & 20 VM & & & & Not present & & \\  & 4 NY4 & & & & Not present & & \\ \hline \multirow{4}{*}{THR309} & 1 TQN & \(-\)7.2559 & \(-\)0.9943 & 0.9943 & 7.2559 & 3.1308 & \(-\)4.1251 \\  & 1W0E & & & & Not present & & \\ \cline{1-1}  & 20 VM & \(-\)7.1833 & \(-\)1.1320 & 1.1320 & 7.1833 & 3.0256 & \(-\)4.1576 \\ \cline{1-1}  & 4 NY4 & \(-\)7.1795 & \(-\)1.1137 & 1.1137 & 7.1795 & 3.0328 & \(-\)4.1466 \\ \hline \multirow{4}{*}{ALA305} & 1 TQN & \(-\)7.1635 & \(-\)0.8966 & 0.8966 & 7.1634 & 3.1334 & \(-\)4.0300 \\ \cline{1-1}  & 1W0E & \(-\)7.2578 & 0.8408 & \(-\)0.8408 & 7.2578 & 4.0493 & \(-\)3.2085 \\ \cline{1-1}  & 20 VM & & & Not present & & \\ \cline{1-1}  & 4 NY4 & & & Not present & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Chemical reactivity parameters of amino acids present in the active sites of CYP3A4 (using different PDB IDs) provided by the interaction with aflatoxin AFB1.