Effect of hydrophobic protein SP-C on structure and dilatational properties of the model monolayers of pulmonary surfactant

The role of hydrophobic protein SP-C on the structure and dilatational rheological properties of the model monolayers of alveolar surfactant was investigated, using a developed rheological approach and atomic force microscopy (AFM) imaging. The non-equilibrium effects due to the reorganization of the cluster lipid monolayers increase with increasing protein content. The results obtained confirm the idea that the hydrophobic pulmonary proteins help to disrupt the bilayers, thereby facilitating the formation of a monolayer at the alveolar surface and the re-spreading of the collapsed phase. The properties of model lipid-protein monolayers were compared with the behaviour of a spread film of commercial seminatural surfactant Curosurf.