Mak122

The purified CFTR in amphipol, purified CFTR in LMNG and the appropriate controls were subjected to a 96-well phospholipid assay kit according to the manufacturer’s protocol (Cat. no. MAK122, Sigma-Aldrich). Fluorescence was read at an excitation of 530 nm and the emission of 585 nm on the SpectraMax i3X plate reader (Molecular Devices).

Particle size, PDI, and zeta potential were determined by dynamic light scattering (DLS) using a Zeta Sizer (Malvern Instruments, Malvern, UK). The formulations were diluted 100-fold with milli-Q water to obtain samples for sizing and zeta potential measurements at room temperature. The respective samples were loaded into the zeta cells (DTS 1070) and analyzed. Phospholipid content of the PFD–Lip and PFD–D-Lip was quantified using a phospholipid assay kit (MAK122, Sigma Aldrich, MO, USA). Briefly, the standard curve of phospholipid was plotted using a colorimetric assay, as per the manufacturer’s instructions. Liposomal formulations were lysed with organic solvent, as described in Section 2.2.1. The supernatants were further diluted with milli-Q water, transferred to 96-well plates, and further steps were carried out according to the protocol, and absorbance was determined on a Spark 10M (Tecan, Männedorf, Switzerland) plate reader at 570 nm.