Ranaspumin-2: structure and function of a surfactant protein from the foam nests of a tropical frog.

ABSTRACT: Ranaspumin-2 (Rsn-2) is a monomeric, 11 kDa surfactant protein identified as one of the major foam nest components of the túngara frog (Engystomops pustulosus), with an amino acid sequence unlike any other protein described so far. We report here on its structure in solution as determined by high-resolution NMR analysis, together with investigations of its conformation and packing at the air-water interface using a combination of infrared and neutron reflectivity techniques. Despite the lack of any significant sequence similarity, Rsn-2 in solution adopts a compact globular fold characteristic of the cystatin family, comprising a single helix over a four-stranded sheet, in a motif not previously associated with surfactant activity. The NMR structure of Rsn-2 shows no obvious amphiphilicity

SUBMITTER: Mackenzie CD 

PROVIDER: S-EPMC2712023 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature