Synthetic amphipathic sequences of surfactant protein-B mimic several physicochemical and in vivo properties of native pulmonary surfactant proteins.

A mixture of lipids and proteins unique to the lung lines the airspaces of all mammalian species. This mixture, termed pulmonary surfactant, is essential for normal lung function. We have synthesized selected amino acid sequences of one of the major low molecular weight surfactant proteins to find whether these peptides can duplicate effects of native protein. Peptide/lipid mixtures approximate results found with native surfactant proteins both in vitro and in vivo. Effects found with native proteins or synthetic peptides include association with, and ordering of, surfactant lipid; changes in surface tension with surface compression; rapid adsorption of lipids from subphase to surface; and improvements in oxygenation of surfactant-deficient rats.