MEMBRANOTROPIC PROPERTIES OF PROTEIN CONJUGATES WITH BLOCK-COPOLYMERS OF ETHYLENE-OXIDE AND PROPYLENE-OXIDE

It was earlier established that conjugates of hydrophilic proteins with block copolymers of ethylene oxide and propylene oxide (proxanols) used at low concentrations decrease the oxidation of NAD-dependent substrates in mitochondria and cells. The dependence of this property on the chemical structure and structural organization of the conjugates has been studied. The conjugates have been shown to inhibit the oxygen consumption in lymphocytes when the hydrophobic (polypropylene oxide) blocks are located on the periphery of the conjugate and the polymer chains form domains that are irregularly distributed on the surface of the protein globule. The minimum number of the polymer chains in the conjugate sufficient to provide this property is three. Additional evidence has been obtained indicating that conjugates can penetrate through the cellular membrane of lymphocytes and reach the NADH-dehydrogenase complex located in mitochondria.