Production and structural studies of lung surfactant protein B (SP-B) peptides

Sharifahmadian, Mahzad (2011) Production and structural studies of lung surfactant protein B (SP-B) peptides. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (21MB)

Abstract

Lung surfactant is a mixture of lipids and proteins which is critical for normal breathing by lining the air-water interface to reduce the surface tension. Lung surfactant protein B (SP-B) is the only essential protein component of lung surfactant complex due to the lethality of any SP-B deficiency. It is thought that SP-B functions by enhancing lipid rearrangements at various phases of the breathing cycle. However, the high-resolution structure and mechanism of SP-B are not yet understood. In the first part of this research, SP-B and a 7-residue deletion mutant of SP-B were produced recombinantly and partially characterized. In the second part of this research, circular dichroism, solution and solid-state nuclear magnetic resonance (NMR) methods were used to assess the structure of two SP-B-based peptides, Super-Mini-B and N-terminal insertion sequence (SP-B₁₋₇). Super-Mini-B is composed of the N-terminal 7-residue insertion sequence and the N-and C-terminal helices of SP-B. Interestingly, it was observed that Super-Mini-B produces greater lipid membrane perturbation than the peptide which lacks the N-terminal insertion sequence (i.e. Mini-B). Comparing the results of structural studies on Mini-B, SP-B₁₋₇ and Super-Mini-B helps unveil the contribution of the 7-residue insertion sequence to the function of SP-B.

Actions (login required)

View Item