STRUCTURAL-CHANGES OF ERYTHROCYTE-MEMBRAN ES IN THE PRESENCE OF FREE FATTY-ACIDS AND THEIR DERIVATIVES

Interaction of free fatty acids and their derivatives with erythrocyte membrane probably leads to a disturbance in the maximum complementari ty between the protein hydrophobic surface and the lipid surroundings in the membrane. The process is accompanied by the inhibition of acety lcholinesterase both in the case of whole erythrocytes and of isolated erythrocyte membranes. The inhibition efficiency and its type depend on the length of the fatty acid alkyl chain and on the terminal group of the inhibitor molecule. The constants of the acetylcholinesterase i nhibition by fatty acids and by the corresponding aldehydes calculated according to Dickson are nearly the same whereas the corresponding fa tty acid methyl esters do not essentially inhibit AChE. The covalent m odification of the erythrocyte membrane by glutaric dialdehyde leads t o non-competitive AChE inhibition which may be related to the limited conformational mobility of membrane proteins.