[Aggregation of membrane proteins of E. coli cells after treatment with singlet oxygen]

It was found that interaction of 1O2 with bacterial membranes of E. coli cells results in covalent binding and aggregation of membrane proteins. This process was shown to be inhibited by water-soluble free radical scavengers, e. g., 1O2 quenchers (cysteine, sodium azide, histidine), of which the latter afforded the strongest inhibition. No protective effect of the fat-soluble free radical scavenger ionol (BHT) on membrane protein aggregation was observed. It was assumed that the main role in oxidative destruction of bacterial membranes (in contrast to membranes from animal sources) is ascribed to processes which are not coupled to lipid peroxidation.