Trehalose Maintains Phase Separation in an Air-Dried Binary Lipid Mixture

Abstract

Mixing and thermal behavior of hydrated and air-dried mixtures of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and 1,2-distearoyl-d70-sn-glycero-3-phosphocholine (DSPCd-70) in the absence and presence of trehalose were investigated by Fourier transform infrared spectroscopy. Mixtures of DLPC:DSPCd-70 (1:1) that were air-dried at 25 degrees C show multiple phase transitions and mixed phases in the dry state. After annealing at high temperatures, however, only one transition is seen during cooling scans. When dried in the presence of trehalose, the DLPC component shows two phase transitions at -22 degrees C and 75 degrees C and is not fully solidified at -22 degrees C. The DSPCd-70 component, however, shows a single phase transition at 78 degrees C. The temperatures of these transitions are dramatically reduced after annealing at high temperatures with trehalose. The data suggest that the sugar has a fluidizing effect on the DLPC component during drying and that this effect becomes stronger for both components with heating. Examination of infrared bands arising from the lipid phosphate and sugar hydroxyl groups suggests that the strong effect of trehalose results from direct interactions between lipid headgroups and the sugar and that these interactions become stronger after heating. The findings are discussed in terms of the protective effect of trehalose on dry membranes.

Role of Calcium Alginate and Mannitol in Protecting Bifidobacterium

“…It appears that Ca-alginate was not able to preserve the fatty acid site of phospholipid bilayers of freeze-dried bacterial cell envelopes during storage at room temperature, even at low a w s. Conversely, storage of CAMB at low a w s and in aluminum foil resulted in lower frequencies than that of the control. The presence of sugars (including mannitol) which interact with polar site of lipids during dehydration inhibits the interior apolar site of lipid changes, such as lipid phase transition and fusion (43), whereas storage at low a w s maintained the glassy state of sugars (31). Hence, lipid stability could be preserved.…”

High-throughput screening of stabilizers for Respiratory Syncytial Virus: Identification of stabilizers and their effects on the conformational thermostability of viral particles

“…In agreement with previous work, it has been shown that trehalose slightly increase the phase transitions of model liposome membranes. 36 It has been proposed that sugars and polyols increase the stability of hydrated membranes due to their water-structuring properties, causing the lipid bilayer to became more closely packed due to an increase in interfacial tension. 36 Gelatin, which has also induced an increase in the membrane phase transition temperatures, may also exert its effects by the same mechanism.…”

“…36 It has been proposed that sugars and polyols increase the stability of hydrated membranes due to their water-structuring properties, causing the lipid bilayer to became more closely packed due to an increase in interfacial tension. 36 Gelatin, which has also induced an increase in the membrane phase transition temperatures, may also exert its effects by the same mechanism. Despite the fact that polyanions inhibited the rate of aggregation of RSV at 56˚C, they appeared to destabilize RSV protein structure.…”

Functional Analysis of Detergent‐Solubilized and Membrane‐Reconstituted ATP‐Binding Cassette Transporters

“…The major bottleneck for direct incorporation of membrane proteins into GUVs is the dehydration step preceding the formation process. When (proteo)liposomes prepared from unsaturated lipids are dried, the transition temperature (T M ) increases by 70-80 (Ricker et al ., 2003). This causes the lipids to go from a liq uid crystalline to a gel phase, which induces lateral phase separation.…”