Elucidating the E‐Cadherin⋯ADTC5 Interactions: A Theoretical Examination of Amino Acid Active Site Binding on the Electronic Level via Density Functional Theory

Abstract

The presence of E‐cadherin⋯E‐cadherin interactions in the intercellular space (paracellular pathway) poses a notable limitation in drug delivery across the blood‐brain barrier (BBB). ADTC5 peptide has shown promising results in improving drug delivery across the BBB by modulating E‐cadherin⋯E‐cadherin interactions. However, the study of E‐cadherin⋯ADTC5 amino acid interactions using quantum mechanics approach has not been observed clearly. Herein, we observed the interaction between E‐cadherin⋯ADTC5 amino acids using density functional theory (DFT). Natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), and reduced density gradient (RDG) analysis are performed to study the non‐covalent interaction in detail. The Arg55⋯Asp2 shows the strongest interaction between E‐cadherin⋯ADTC5 modulation, indicated by the highest stabilization energy (E(2)), and hydrogen bonding energy (EHB) about 22.04 and −6.90 kcal/mol, respectively. This interaction is dominated by hydrogen bonding. Such advancements could lead to significant improvements in therapeutic strategies for neurodegenerative diseases, where effective drug delivery across the BBB remains a major challenge.