Temperature effect on the interaction of polyethylene glycol with membranes and orientation order of cytoskeleton proteins in human erythrocytes

Abstract

The study identified discrepancies in the modification of erythrocyte membrane upon exposure to polyethylene glycol with a molecular weight of 1500 (PEG) at various temperatures (4 and 37 °C) using the fluorescent probe 4-(n-dimethylaminostyryl)-1-methylpyridinium-n-toluenesulfonate (DSM), as well as alterations in the orientation order of proteins in the membrane-cytoskeleton complex using polarization microscopy. Exposure of erythrocytes to PEG at 37 °C caused complete disappearance of the hydrophobic component from the DSM fluorescent spectrum due to competition between PEG and DSM molecules for binding sites. Lowering the exposure temperature of cells to a cryoprotective agent (CPA) to 4 °C reduced the possibility of its hydrophobic contacts with cell membranes attested by the presence of the hydrophobic component in the DSM spectrum, although at a lower level than in the control. The decrease in hydrophobic contacts of PEG to membranes upon a lowering temperature at the stage of erythrocyte exposure to CPA provided retaining to a large extent the orientation order of the membrane cytoskeleton molecules both under the incubation process with CPA and after freeze–thawing of cells.

Probl Cryobiol Cryomed. 2026; 36(1): 16—26.