Assembly and Interfacial Mechanics of Recombinant Surfactant Protein B in Mixed Detergent Systems and Lipid Monolayers

Recombinant surfactant protein B (rSP-B) forms a dominant ~600 nm mesoscale assembly in DPC/SDS (9:1, 0.2% w/v) after dialysis, retaining ~47% alpha-helical structure.

• Why it matters: Mature SP-B structure and the molecular basis of its pulmonary function remain undetermined, and detergent/interfacial conditions likely control how SP-B assembles and acts.
• What they did: Light scattering mapped DPC/SDS heterogeneity (~4 nm micelles and ~68–400 nm supramicellar structures), while dialysis and 200 nm filtration tested rSP-B association; monolayer assays used DPPC/POPG.
• The result: rSP-B incorporation into DPPC/POPG monolayers stabilized hysteresis and attenuated cycling-induced area loss, with compressibility signatures consistent with out-of-plane deformation and reversible reorganization of collapsed material.