Topology and lipid selectivity of pulmonary surfactant protein SP-B in membranes: Answers from fluorescence

► Time-resolved fluorescence of SP-B allows studying selectivity and mode of L/P interaction. ► SP-B shows selectivity for anionic lipids but not specifically for NBD-PG. ► A model has been derived to interpret FRET from peripheral membrane protein donors. ► FRET data from SP-B indicates that the protein interacts with membranes in a superficial manner.