Endobain E, a brain endogenous factor, is present and modulates NMDA receptor in ischemic conditions

In silico insight into Amurensinine - an N-Methyl-D-Aspartate receptor antagonist

BACKGROUND

Some isopavines can exhibit important biological activity in the treatment of neurological disorders since it is considered an antagonist of the specific N-methyl-D-Aspartate (NMDA) receptor. Amurensinine is an isopavine which still has few studies. In view of the potential of isopavines as NMDA receptor antagonists, theoretical studies using bioinformatics were carried out in order to investigate whether Amurensinine binds to the NMDA receptor and to analyze the receptor/Ligand complex. This data can contribute to understanding of the onset of neurological diseases and contribute to the planning of drugs for the treatment of neurological diseases involving the NMDA receptor.

AIM

To investigate the interaction of the antagonist Amurensinine on the GluN1A/ GluN2B isoform of the NMDA receptor using bioinformatics.

METHODS

The three-dimen-sional structure of the GluN1A/GluN2B NMDA receptor was selected from the Protein Data Bank (PDB) - PDB: 4PE5, and the three-dimen-sional structure of Amurensinine (ligand) was designed and optimized using ACD/SchemsketchTM software. Prediction of the protonation state of Amur-ensinine at physiological pH was performed using MarvinSketch software (ChemAxon). Protonated and non-protonated Amurensin were prepared using AutoDock Tools 4 software and simulations were performed using Autodock Vina v.1.2.0. The receptor/Ligand complexes were analyzed using PyMol (Schrödinger, Inc) and BIOVIA Discovery Studio (Dassault Systemes) software. To evaluate the NMDA receptor/Amurensinine complex and validate the molecular docking, simulations using NMDA receptor and Ifenprodil antagonist were performed under the same conditions. Ifenprodil was also designed, optimized and protonated, under the same conditions as Amurensinine.

RESULTS

Molecular docking simulations showed that both non-protonated and protonated Amurensinine bind to the amino terminal domain (ATD) domain of the GluN1A/GluN2B NMDA receptor with significant affinity energy, -7.9 Kcal/mol and -8.1 Kcal/mol, respectively. The NMDA receptor/non-protonated Amurensinine complex was stabilized by 15 bonds, while the NMDA receptor/protonated Amurensinine complex was stabilized by less than half, 6 bonds. Despite the difference in the number of bonds, the variation in bond length and the average bond length values are similar in both complexes. The complex formed by the NMDA receptor and Ifenprodil showed an affinity energy of -8.2 Kcal/mol, a value very close to that obtained for the NMDA receptor/Amurensinine complex. Molecular docking between Ifenprodil and the GluN1A /GluN2B NMDA receptor demonstrated that this antagonist interacts with the ATD of the receptor, which validates the simulations performed with Amurensinine.

CONCLUSION

Amurensinine binds to the NMDA receptor on ATD, similar to Ifenprodil, and the affinity energy is closer. These data suggest that Amurensinine could behave as a receptor inhibitor, indicating that this compound may have a potential biological application, which should be evaluated by in vitro and preclinical assays.

Heart Failure-Induced Brain Injury

Heart failure (HF) is a systemic illness with grave implications for bodily functions. The brain, among other vital organs, often suffers insults as a result of HF, and both anatomic and functional brain abnormalities were found in the HF population. This injury was demonstrated across a wide range of clinical conditions and cardiac functions and was shown to affect patients' outcomes. Although reduced cardiac output and high burden of cardiovascular risk factors are the prevailing explanations for these findings, there are data showing the involvement of neurohormonal, nutritional, and inflammatory mechanisms in this complex process. Here, the authors review the suggested pathophysiology behind brain injury in HF, describe its effect on patients' outcomes, offer a diagnostic approach, and discuss possible therapeutic options.