Measurement of Lysophospholipid Transport Across the Membrane Using Escherichia coli Spheroplasts.

In the inner membrane of Gram-negative bacteria lysophospholipid transporter (LplT) and the bifunctional acyl-acyl carrier protein (ACP) synthetase/2-acylglycerolphosphoethanolamine acyltransferase (Aas) form a glycerophospholipid remodeling system, which is capable of facilitating rapid retrograde translocation of lyso forms of phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin across the cytoplasmic membrane. This coupled remodeling enzyme tandem provides an effective method for the measurement of substrate specificity of the lipid regeneration and lysophospholipid transport per se across the membrane. This chapter describes two distinct but complementary methods for the measurement of lysophospholipid transport across membrane using Escherichia coli spheroplasts.