The effect of high hydrostatic pressure on the mechanism of transfer for lipophiles between membranes was investigated. The transfer of fluorescent phosphatidylcholine (1-myristoyl-2- left bracket 9 prime -(3 prime -pyrenyl)nonanoyl right bracket phosphatidylcholine) between recombinant complexes of apolipoprotein A-I and 1-palimitoyl-2-oleoylphosphatidylcholine occurred via the aqueous compartment. High hydrostatic pressure retarded the rate of transfer, resulting in a positive activation volume for the reaction. The calculated free energy of activation was approximately 23 kcal/mol. The positive activation volume presumably corresponds to the work necessary to overcome pressure-induced compression of the membrane (protein-lipid complex) before transfer can occur.
ASJC Scopus subject areas
- Colloid and Surface Chemistry