With S/V0 as the initial vesicle surface area to volume ratio (measurable by dynamic light scattering) Pf can be expressed as:equation(5)Pf=kS/V0vwΔosm,where k (in s− 1) is the time constant associated with the volume change and Δosm is the difference in osmolarity between the intra-vesicular and extra-vesicular aqueous solutions. Experimental values for k are obtained by fitting the scattered intensity I(t) to an exponential function. If the protein content per vesicle is known one can use Eq. (5) to determine an upper limit for the single channel osmotic permeability pf.
2.4. Solute rejection
A major requirement for the use of AQPs in biomimetic membrane applications is protein (-)-JQ1 towards external perturbations during protein reconstitution, and membrane function. For the plant orthodox spinach aquaporin SoPIP2;1 Plasencia et al. showed that it can exist as a stable folded protein in octyl-β-d-glucopyranoside (OG) detergent micelles solutions and that the protein can be transferred from detergent micelle solutions and reconstituted into selected phospholipid membranes preserving its structural characteristics . This study was followed by a comparative study revealing that the anionic detergent sodium dodecyl sulfate (SDS) does not unfold neither SoPIP2;1, nor AqpZ during transition from a membrane reconstituted form to a detergent stabilized state albeit the native folds are changed . Thus it is evident that AQPs may be isolated, purified, and inserted into a biomimetic host matrix, while preserving functionality.