Electrostatic medium effects upon histamine H2 receptor activation

Abstract

In order to examine environmental effects, the interaction oí histamine (HA) with a model of the H2 receptor was analyzed using the self-consistent reaction field theory at the CNDO/21evel, in vacuo, and in the presence oí a polarlzable continuum medium. The main findings reported in this work are: (a) a concerted proton movement is not possible in vacuo or in the presence oí a polarlzable medium; (b) the most stable form in all the systems and environments analyzed is the one in which there is a proton transference from the model site to HA; (c) it seems necessary to consider other possibilities in the receptor modeling in order to sustain the HA receptor activation hypothesis.