2WGO

Structure of ranaspumin-2, a surfactant protein from the foam nests of a tropical frog

2WGO の概要

• エントリーDOI: 10.2210/pdb2wgo/pdb
• 分子名称: RANASPUMIN-2 (1 entity in total)
• 機能のキーワード: cystatin fold, surfactant protein
• 由来する生物種: ENGYSTOMOPS PUSTULOSUS (TUNGARA FROG)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 11286.92

構造登録者

Mackenzie, C.D.,Smith, B.O.,Kennedy, M.W.,Cooper, A. (登録日: 2009-04-21, 公開日: 2009-06-23, 最終更新日: 2024-11-20)

主引用文献

Mackenzie, C.D.,Smith, B.O.,Meister, A.,Blume, A.,Zhao, X.,Lu, J.R.,Kennedy, M.W.,Cooper, A.
Ranaspumin-2: Structure and Function of a Surfactant Protein from the Foam Nests of a Tropical Frog.
Biophys.J., 96:4984-, 2009

PubMed 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 that might be anticipated for a surfactant protein. This suggests that it must undergo a significant conformational change when incorporated into the air-water interface that may involve a hinge-bending, clamshell opening of the separate helix and sheet segments to expose hydrophobic faces to air while maintaining the highly polar surfaces in contact with the underlying water layer. This model is supported by direct observation of the relative orientations of secondary structure elements at the interface by infrared reflection absorption spectroscopy, and by protein packing densities determined from neutron reflectivity profiles.

PubMed: 19527658
DOI: 10.1016/J.BPJ.2009.03.044

実験手法

SOLUTION NMR