Influence of Long-Tailed Alcohols on the Solubilisation of Cationic DHAB Bilayers

Abstract

Abstract:The effects of n-decanol and cetyl alcohol incorporated into cationic di-n-hexadecyldimethylammonium bromide (DHAB) bilayers on the packing and the resistance against solubilisation by Triton X-100 have been investigated. Solubilisation experiments revealed that the mismatch between the C 10 -tail of n-decanol with the DHAB-tails does not affect the structural integrity of the vesicles. On the contrary, upon increasing amounts of cetyl alcohol, of which the tail matches in size with the DHAB-tails, breakdown of the vesicles is promoted, whereas complete solubilisation is strongly hampered. The system is further investigated by DSC and cryo-EM experiments. In addition, the effects of n-decanol and cetyl alcohol embedded into DHAB bilayers on the vesicular rate constants for the decarboxylation of 6-nitrobenzisoxazole-3-carboxylate (6-NBIC) suggest that both alcohols affect the structure of the Stern region in an equal manner, leading to a decrease in the catalysis. Therefore, it is concluded that addition of the alcohols leads to changes in properties of the interior of the bilayer, rather than the polar-apolar interface.

Vesicular Catalysis of an SN2 Reaction: Toward Understanding the Influence of Glycolipids on Reactions Proceeding at the Interface of Biological Membranes

“…Experiments were performed at 35 °C, since this is above the main phase transition temperature of all amphiphilic components. This is important since below the main phase transition temperature bilayer fragments, rather then closed spherical vesicles, are observed for aggregates formed from C 16 C 16 + . ,, …”

Vesicular catalysis of the decarboxylation of 6‐nitrobenzisoxazole‐3‐carboxylate. The effects of sugars, long‐tailed sugars, cholesterol and alcohol additives

“…13 At these concentrations the 6-NBIC substrate is completely bound to the vesicular interface owing to the relative excess of DHAB and the high binding constant of 6-NBIC (>10 3 M…”

“…13 A total amphiphile concentration of 2 mM and 2.25 mM sodium hydroxide were used for the experiments. Five scans were taken between 5 and 1008C at a scan rate of 18C min…”