[Effect of the pH of the medium and chemical modification of protein on the activity of bradykinin angioreceptors].

Study of the effect of medium pH on the mechanism of bradykinin interaction with receptors allowed a suggestion about the presence of a protein component in the composition of bradykinin receptor. Quantitative determination of the pH-dependence of the kinetic parameters of the kininergic reaction indicates the involvement of sulfhydryl groups in the formation of the active center in bradykinin receptor. This finding is supported by experiments with receptor blockade by reagents used for chemical modification of protein. The data obtained also attest to a possible involvement of the imidazole group of histidine in the realization of the myotropic effect of bradykinin.