Reports of Biochemistry and Molecular Biology

en Tight Junction Modulatory Fusion Peptide (ADT-6) Enhances GFP Protein Permeability through the Paracellular Pathway in Caco-2 Cell Lines: An In-Vitro Study زیست شناسی ملکولی Molecular Biology مقالات اصلی Original Article <div style="text-align: justify;">Background: The oral delivery of therapeutic peptides and proteins presents a significant challenge in pharmaceutical development due to barriers such as the intestinal epithelium and the blood-brain barrier (BBB). These barriers limit the passage of large, hydrophilic molecules through transcellular pathways and restrict paracellular transport due to intercellular tight junctions. This study investigates the potential of E- cadherin-modulating peptide, ADT-6, to improve the penetration of these therapeutic agents. Methods: We constructed a fusion protein of ADT-6 and green fluorescent protein (GFP) to evaluate its activity and transport through the epithelial cells' paracellular pathway. Using Escherichia coli strains for expression, we cloned the GFP-ADT-6 construct, which provides a solid foundation for our study's methodology. Results: Our molecular simulations showed that the linker between GFP and ADT-6 maintains the fusion protein's integrity and provides flexibility in receptor interaction. Permeability experiments revealed that ADT-6 markedly reduced transepithelial electrical resistance (TEER) and significantly increased GFP transfection in Caco-2 cell monolayers dose-dependently. Results of ELISA confirmed these findings, showing high GFP levels in the lower compartment of Transwell systems treated with GFP-ADT-6. Conclusions: This study demonstrates the potential of ADT-6 to deliver proteins from the paracellular route, enhance the bioavailability of pharmaceutical drugs by altering cell-cell interactions, and provide new opportunities for oral drug delivery strategies.  </div> Caco-2 cells, Tight Junctions, Permeability, Recombinant fusion protein. 349 357 http://rbmb.net/browse.php?a_code=A-10-1609-1&slc_lang=en&sid=1 Salimeh Hassani 100319475328460020688 100319475328460020688 No Department of Medical Biotechnology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Keyvan Nedaei 100319475328460020689 100319475328460020689 No Department of Medical Biotechnology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Rahim Jafari 100319475328460020690 100319475328460020690 No Nanotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran. Ghasem Bagherpour g_bagherpour@zums.ac.ir. 100319475328460020691 100319475328460020691 Yes Zanjan Pharmaceutical Biotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran.