AMIDO-LINKED AND CARBAMOYL-LINKED PSEUDOGLYCERYL LIPIDS AND LIPOSOMALDYNAMICS

There is little difference between the trans-bilayer Lipid migration ( flip-flop) behavior of ester-, ether-, amido-, or carbamoyl-linked lip ids 1-5 in coliposomes of 1-F/1-NF - 5-F/5-NF. Flip-flop is slow at te mperatures below the gel to liquid crystal transition temperature (T-c ) and rapid (<5 min) at temperatures that are significantly greater th an T-c. There is no evidence for enhanced stability toward flip-flop o n the part of amido or carbamoyl-linked lipids 3-5 due to direct or wa ter-mediated H-bonding involving their N-H groups.