Abstract | The platelet activating factor, PAF, has been recently identified as an ether lipid with dramatic bioreactivity. The present IR spectroscopic investigation demonstrates that in an aqueous environment PAF can assume three different structures, a micellar form at tempera-tures above 21°C, a solid-like opaque lamellar form at temperatures below 12°C, and an intermediate transparent lamellar form that exists at temperatures between 12 and 21ðC. The three structures are separated by two reversible phase transitions; however, the rate of the reversed micellar to lamellar change is negatively temperature dependent, i.e., about 6 min at -1°C and 12 min at 3°C, and slower than the lamellar to micellar change. |
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