Abstract:

The active site of Met-enkephalin was studied by calculation of electrostatic potential, using AM1 semi empirical quantum chemistry methed. The results of calculation show that the lowest value of electrostatic potential is near to the position of Tyr amino N and the lowest atomic charge derived from electrostatic potential is also located on that N atom. There are less quantity of charge on phenyl of Tyr. It means that this is a hydrophobic group. These sites interact with receptor by electrostatic and hydrophobic interactions. The results of calculation also show that it is a better and more effective method to study the active site of drugs by electrostatic potential and atomic charges derived from molecular electrostatic potential.

Key words: Met-enkephalin, Electrostatic potential, Charges, Activity site, Computer simulation