LIPID TRANSMEMBRANE ASYMMETRY AND FLIP-FLOP IN BIOLOGICAL-MEMBRANES AND IN LIPID BILAYERS

During the past year, the body of evidence indicating that specific pr oteins are involved in the transmembrane redistribution of phospholipi ds in the membranes of eukaryotic cells has grown; however, no such pr otein has been unambiguously identified. A comparable effort has been directed towards attempting to unravel the mechanism(s) responsible fo r phospholipid transmembrane segregation and phospholipid scrambling. The physiological implications of the modulation of lipid asymmetry ar e beginning to emerge; they comprise control of enzyme activity, surfa ce recognition and shape changes.