Abstract
Pulmonary surfactant is a mixture of phospholipids, neutral lipids, and associated proteins. A specific phospholipid, dipalmitoylphosphatidylcholine, is predominantly responsible for the modulation of surface tension at the alveolar air-liquid interface, but other surfactant lipid and protein components play important roles in surfactant function and metabolism. This review will focus on just one of the apoproteins, surfactant protein B, with a description of protein structure and the actions of surfactant protein B on surfactant lipid membranes.