Deuterium and phosphorous NMR spectra taken at 38°C. (A) 2H spectra of 4:1 DPPC-d62/POPG MLVs, (B) 2H spectra 4:1 DPPC/POPG-d31 MLVs, (C) 31P spectra of 4:1 DPPC-d62/POPG MLVs, (D) 2H spectra of 3:1 POPC-d31/POPG MLVs, (E) 2H spectra of 3:1 POPC/POPG-d31 MLVs, and (F) 31P spectra of 3:1 POPC-d31/POPG MLVs with SP-B1-25 at the indicated molar percentages.