[Comparative study of membrane-bound acetylcholinesterase in guinea pig and rabbit brains]

As a result of kinetic studies on acetylcholinesterase inhibition by allosteric effector d-tubocurarine it was shown that interaction between modifier and catalytic sites of rabbit and guinea pig acetylcholinesterase are different for these two species. Judging by the inhibition curves and sensitivity of d-tubocurarine theses differences involve enzyme microenvironment in the membrane. Addition to 7,15-10-6 M d-tubocurarune to solubilized preparation led to a significant fall in the value of Hill coefficient for enzyme-substrate interaction. This may be indicative of the changes in the conformational state of the enzyme after its dissociation from the membrane, i. e. of the membrane structure role in the formation of the structural and functional enzyme properties.