Phosphatidylcholine was extracted from egg yolks and sonicated with n-alkyl alcohols to give vesicles. The magnetic environment of the external compartment was then modified by the addition of shift reagent (Co2+). This allowed determination of the average lifetime for exchange of water molecule protons by observing the relaxation rate dependence on the interval between pulses in a Carr-Purcell sequence. For vesicles containing n-hexanol as 33% of lipid, the average water molecule lifetime in the internal compartment was found to be substantially less than that for a vesicle without hexanol. The lifetime, 11.3±4 msec, is equivalent to a permeability coefficient of 60 μ/sec at 34°C.
All Science Journal Classification (ASJC) codes
- Cell Biology