Interaction studies on catecholamines to cellular receptors using in silico approach

Catecholamines are organic compounds derived from amino acids tyrosine and phenylalanine, which acts as neurotransmitters and also functions as hormones in the blood circulation. They bind to plasma proteins and circulate in the blood stream. High levels of catecholamines will cause increase in the heart rate, blood pressure and blood glucose level. These effects are due to binding of catecholamines with adrenergic receptors. Therefore the objective of the current research work is to know the binding affinity of catecholamines with adrenergic receptors through in silico approach. For this study, four catecholamines and three adrenergic receptors were selected for binding analysis. The three natural catecholamines are epinephrine, nor-epinephrine, dopamine and a synthetic catecholamine is Isoproterenol. The three selected receptors are 1GQ4, 3D4S and 1BAK. Binding effect of the four neurotransmitters with the three receptors was studied through in silico analysis using softwares. PATCH DOCK and Z DOCK online servers were used to analyze the docking scores and internal energy was observed by Accelrys Discovery studio. From this study the synthetic catecholamine Isoproterenol showed maximum binding score with all three adrenergic receptors comparing to 3 natural catecholamines. The internal energy of Isoproterenol was found to be 35.18127 kJ/mol. Therefore the study concludes the synthetic catecholamine Isoproterenol has more binding affinity towards beta adrenergic receptors comparing to natural catecholamines. Hence, the current study suggests the usage of synthetic catecholamines will have more binding affinity with adrenergic receptors which could be further analyzed using in vivo study as a future work.