EFFECT OF FREE FATTY-ACIDS ON THE STRUCTURE AND PROPERTIES OF ERYTHROCYTE-MEMBRANE

The changes in the structure and properties of erythrocyte membranes t hat are induced by free fatty acids and their derivatives have been st udied. The state of the membrane has been evaluated using the activity of membrane-bound acetylcholinesterase (AChE), the pyrene monomer/exc imer fluorescence intensity ratio as an indicator of membrane lipid mi croviscosity and the fluorescence of membrane-bound 1-anilinonaphtalen e-8-sulphonic acid (ANS). Free fatty acids and corresponding aliphatic aldehydes induced an inhibition of membrane-bound AChE, effectively d ecreased the bulk lipid and protein-bound lipid microviscosity, and qu enched the fluorescence of membrane-bound ANS. The type and efficiency of the enzyme inhibition, as well as the efficiency of microviscosity decrease and ANS fluorescence quenching, depended on the hydrophobici ty and the end group in the effector molecule. Therefore, it is propos ed that fatty acids and related compounds perturb the lipid bilayer an d disturb the protein-lipid complementarity of the human erythrocyte m embrane.