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Updated: Aug 18, 2026

Detergent-free Ultrafast Reconstitution of Membrane Proteins into Lipid Bilayers Using Fusogenic Complementary-charged Proteoliposomes.
Published on: April 5, 2018
Ultrastructure of phospholipid mixtures reconstituted with surfactant proteins B and D
F R Poulain1, J Akiyama, L Allen
1Cardiovascular Research Institute and Departments of Pediatrics, Medicine, and Physiology, University of California San Francisco, San Francisco, California, USA. poulain@itsa.ucsf.edu
Abstract:
Surfactant protein (SP)-D is secreted from pulmonary alveolar type II cells into the alveolar lumen where potential interactions with surfactant lipids might occur. SP-D binds phosphatidylinositol (PI), a component of mammalian surfactants that is increased in a variety of injury states. We investigated the ultrastructure and properties of lipid protein recombinants that included SP-D, PI, and SP-B and compared these with recombinants based on SP-A. SP-D had a profound effect on the organization of phospholipid vesicles containing PI and SP-B, promoting the formation of atypical but highly ordered and surface-active tubular aggregates distinct in their dimensions and shape from the classical tubular myelin formed by SP-A. We also found both types of tubules in the secretions of type II cells maintained in long-term culture. These results suggest that surface atypical tubules can be formed with SP-D in vitro and in vivo.
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