Showing papers by "Kaixian Chen published in 1996"

Molecular modeling of mu opioid receptor and its interaction with ohmefentanyl.

Abstract: "AIM: To build up the structure model of mu opioid receptor, then combined with the receptor model, to investigate the action mechanism of ohmefentanyl on the receptor. METHODS: Using the three-dimensional structure of bacteriorhodopsin as a template, we constructed mu opioid receptor model on computer. Ohmefentanyl was then docked into the supposed receptor binding sites. RESULTS: A good ligand-receptor interaction model was achieved. The possible binding sites were found to be Asp147 and His319. The protonated N atom of ohmefentanyl form potent electrostatic and hydrogen-bonding interactions with residue Asp147 of the receptor, the O atom of the carbonyl group form weak electrostatic and hydrogen-bonding interactions with residue His319, and the two phenyl groups form pi-pi interactions with some aryl residues of the receptor around ligand. CONCLUSION: The ligand-receptor interaction model should be helpful for rational design of novel analgesic. "

Molecular modeling of interactions between tetrahydroprotoberberines and dopamine receptors.

Abstract: "AIM: To build up the structure models of dopamine receptors, then combined with the receptor models, to investigate the action mechanism of tetrahydroprotoberberines (THPB) on dopamine receptors at the molecular level. METHODS: Using the three-dimensional structure of bacteriorhodopsin as a template, we have constructed dopamine D1 and D2 receptor models on computer. l-Stepholidine was selected as the leading compound of THPB and docked into D1 and D2 receptor active sites. RESULTS: After manual adjustment and energy minimization, the ligand-receptor interaction models were achieved. Based on these models, the possible action mechanism of THPB on dopamine receptors was suggested that the protonated N atom of THPB form electrostatic interaction and hydrogen-bonding interaction with residue Asp in TM3 of the receptor, the two substituents in D ring of THPB form hydrogen-bonding interactions with two Ser residues in TM5 of the receptor, and the aryl groups form pi-pi interactions with some aryl residues of the receptor around ligand. CONCLUSION: Our ligand-receptor interaction models should be helpful for rational design of more potent drugs. "