Selective Inhibition on RAGE-binding AGEs Required by Bioactive Peptide Alpha-S2 Case in Protein from Goat Ethawah Breed Milk: Study of Biological Modeling.

BACKGROUND: Advanced Glycation End Products (AGE) play a pivotal role in the development various degenerative diseases such as diabetes, cardiovascular disease, stroke, neuropathy, and nephropathy. Different studies have been done to employ AGEs as drug targets for the diseases therapy. In previous study, we have found bioactive peptide from Ethawah goat milk for anti-diabetic that may work through inhibition of AGE receptor function. However, the mechanism of bioactive peptides inhibits AGE- AGE receptor (RAGE) bonding still not clear yet. Therefore we investigated the inhibition mechanism by calculate the potential energy binding among the peptides, AGEs and RAGE using molecular docking system.

METHODS: Modeling 3D-structure was predicted by SWISS-MODEL web server. The virtual interaction was analyzed by docking system using HEX 8.0, Pymol and Discovery Studio 4.0 software.

RESULTS: this study showed that AGEs (Argypirimidine, Imidazole, Pentosidine and Pyrraline) bind to C-domain of RAGE. The total energy binding of RAGE with Argypirimidine, Imidazole, Pentosidine and Pyrraline were 378.35kJ/mol, -74.57kJ/mol, -301.25kJ/mol and -400.72kJ/mol, respectively. We have found three peptides among eight peptides from Ethawah goat milk, which are able bind to C-domain of RAGE, there are CSN1S2 f41-47, CSN1S2 f182-189, and CSN1S2 f214-221. The CSN1S22 f41-47 at arginine residue 47 interacts with proline162, leusine163 and leusine158 of RAGE. The total binding energy between CSN1S2 f41-47, CSN1S2 f182-189, and CSN1S2 f214-221 with RAGE were -378.35 kJ/mol, -359.97kJ/mol, -356.78 kJ/mol, respectively. Total binding energy and binding pattern indicated that RAGE more prefer bind with peptide and block AGE bind to functional site of RAGE. Further analysis showed that complex peptide-RAGE shifted binding site of AGE on function domain RAGE.

CONCLUSION: This study suggested that the peptides from Ethawah goat milk may act as an inhibitor of AGEs-RAGE interaction that impaired signal transduction cascade at the cellular level.