SFTPC is a 197-residue protein made up of two halves: a unique N-terminal propeptide domain and a C-terminal BRICHOS domain. The around 100-aa long propeptide domain actually contains not only the cleaved part, but also the mature peptide. It can be further broken down into a 23-aa helical transmembrane propeptide proper, the mature secreted SP-C (24-58), and a linker (59-89) that connects to the BRICHOS domain.[8]
The propeptide of pulmonary surfactant C has an N-terminal alpha-helical segment whose suggested function was stabilization of the protein structure, since the mature peptide can irreversibly transform from its native alpha-helical structure to beta-sheet aggregates and form amyloid fibrils. The correct intracellular trafficking of proSP-C has also been reported to depend on the propeptide.[9]
The structure of the BRICHOS domain has been solved. Mutations in this domain also lead to amyloid fibrils made up of the mature peptide, suggesting a chaperone activity.[8]
^Li J, Liepinsh E, Almlén A, Thyberg J, Curstedt T, Jörnvall H, Johansson J (March 2006). "Structure and influence on stability and activity of the N-terminal propeptide part of lung surfactant protein C". The FEBS Journal. 273 (5): 926–35. doi:10.1111/j.1742-4658.2006.05124.x. PMID16478467.
Pérez-Gil J (2002). "Lipid-protein interactions of hydrophobic proteins SP-B and SP-C in lung surfactant assembly and dynamics". Pediatric Pathology & Molecular Medicine. 20 (6): 445–69. doi:10.1080/15227950152625783. PMID11699574.
Solarin KO, Wang WJ, Beers MF (2002). "Synthesis and post-translational processing of surfactant protein C". Pediatric Pathology & Molecular Medicine. 20 (6): 471–500. doi:10.1080/15227950152625792. PMID11699575.
Johansson J, Curstedt T, Robertson B (2002). "Artificial surfactants based on analogues of SP-B and SP-C". Pediatric Pathology & Molecular Medicine. 20 (6): 501–18. doi:10.1080/15227950152625800. PMID11699576.
Simatos GA, Forward KB, Morrow MR, Keough KM (June 1990). "Interaction between perdeuterated dimyristoylphosphatidylcholine and low molecular weight pulmonary surfactant protein SP-C". Biochemistry. 29 (24): 5807–14. doi:10.1021/bi00476a023. PMID2383558.
Glasser SW, Korfhagen TR, Perme CM, Pilot-Matias TJ, Kister SE, Whitsett JA (July 1988). "Two SP-C genes encoding human pulmonary surfactant proteolipid". The Journal of Biological Chemistry. 263 (21): 10326–31. PMID2839484.
Glasser SW, Korfhagen TR, Weaver TE, Clark JC, Pilot-Matias T, Meuth J, et al. (January 1988). "cDNA, deduced polypeptide structure and chromosomal assignment of human pulmonary surfactant proteolipid, SPL(pVal)". The Journal of Biological Chemistry. 263 (1): 9–12. PMID3335510.
Johansson J, Jörnvall H, Eklund A, Christensen N, Robertson B, Curstedt T (May 1988). "Hydrophobic 3.7 kDa surfactant polypeptide: structural characterization of the human and bovine forms". FEBS Letters. 232 (1): 61–4. doi:10.1016/0014-5793(88)80386-7. PMID3366248.
Wood S, Yaremko ML, Schertzer M, Kelemen PR, Minna J, Westbrook CA (December 1994). "Mapping of the pulmonary surfactant SP5 (SFTP2) locus to 8p21 and characterization of a microsatellite repeat marker that shows frequent loss of heterozygosity in human carcinomas". Genomics. 24 (3): 597–600. doi:10.1006/geno.1994.1673. PMID7713515.
Hatzis D, Deiter G, deMello DE, Floros J (1994). "Human surfactant protein-C: genetic homogeneity and expression in RDS; comparison with other species". Experimental Lung Research. 20 (1): 57–72. doi:10.3109/01902149409064373. PMID8181452.
Nogee LM, Dunbar AE, Wert SE, Askin F, Hamvas A, Whitsett JA (February 2001). "A mutation in the surfactant protein C gene associated with familial interstitial lung disease". The New England Journal of Medicine. 344 (8): 573–9. doi:10.1056/NEJM200102223440805. PMID11207353.