SFTPC is a 197-residue protein made up of two halves: a unique N-terminalpropeptide domain and a C-terminalBRICHOS 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 formamyloid 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 achaperone activity.[8]
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.
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.
