Abstract
SP-C, a pulmonary surfactant-specific protein, aids the spreading of the main surfactant phospholipid L-alpha-dipalmitoylphosphatidylcholine (DPPC) across air/water interfaces, a process that has possible implications for in vivo function. To understand the molecular mechanism of this process, we have used external infrared reflection-absorption spectroscopy (IRRAS) to determine DPPC acyl chain conformation and orientation as well as SP-C secondary structure and helix tilt angle in mixed DPPC/SP-C monolayers in situ at the air/water interface. The SP-C helix tilt angle changed from approximately 24 degrees to the interface normal in lipid bilayers to approximately 70 degrees in the mixed monolayer films, whereas the acyl chain tilt angle of DPPC decreased from approximately 26 degrees in pure lipid monolayers (comparable to bilayers) to approximately 10 degrees in the mixed monolayer films. The protein acts as a "hydrophobic lever" by maximizing its interactions with the lipid acyl chains while simultaneously permitting the lipids to remain conformationally ordered. In addition to providing a reasonable molecular mechanism for protein-aided spreading of ordered lipids, these measurements constitute the first quantitative determination of SP-C orientation in Langmuir films, a paradigm widely used to simulate processes at the air/alveolar interface.
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Selected References
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- Blume A., Hübner W., Messner G. Fourier transform infrared spectroscopy of 13C = O-labeled phospholipids hydrogen bonding to carbonyl groups. Biochemistry. 1988 Oct 18;27(21):8239–8249. doi: 10.1021/bi00421a038. [DOI] [PubMed] [Google Scholar]
- Brauner J. W., Mendelsohn R., Prendergast F. G. Attenuated total reflectance Fourier transform infrared studies of the interaction of melittin, two fragments of melittin, and delta-hemolysin with phosphatidylcholines. Biochemistry. 1987 Dec 15;26(25):8151–8158. doi: 10.1021/bi00399a020. [DOI] [PubMed] [Google Scholar]
- Briggs M. S., Cornell D. G., Dluhy R. A., Gierasch L. M. Conformations of signal peptides induced by lipids suggest initial steps in protein export. Science. 1986 Jul 11;233(4760):206–208. doi: 10.1126/science.2941862. [DOI] [PubMed] [Google Scholar]
- Cornut I., Desbat B., Turlet J. M., Dufourcq J. In situ study by polarization modulated Fourier transform infrared spectroscopy of the structure and orientation of lipids and amphipathic peptides at the air-water interface. Biophys J. 1996 Jan;70(1):305–312. doi: 10.1016/S0006-3495(96)79571-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Creuwels L. A., Demel R. A., van Golde L. M., Benson B. J., Haagsman H. P. Effect of acylation on structure and function of surfactant protein C at the air-liquid interface. J Biol Chem. 1993 Dec 15;268(35):26752–26758. [PubMed] [Google Scholar]
- Flach C. R., Brauner J. W., Mendelsohn R. Calcium ion interactions with insoluble phospholipid monolayer films at the A/W interface. External reflection-absorption IR studies. Biophys J. 1993 Nov;65(5):1994–2001. doi: 10.1016/S0006-3495(93)81276-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flach C. R., Brauner J. W., Taylor J. W., Baldwin R. C., Mendelsohn R. External reflection FTIR of peptide monolayer films in situ at the air/water interface: experimental design, spectra-structure correlations, and effects of hydrogen-deuterium exchange. Biophys J. 1994 Jul;67(1):402–410. doi: 10.1016/S0006-3495(94)80495-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hawgood S. Pulmonary surfactant apoproteins: a review of protein and genomic structure. Am J Physiol. 1989 Aug;257(2 Pt 1):L13–L22. doi: 10.1152/ajplung.1989.257.2.L13. [DOI] [PubMed] [Google Scholar]
- Johansson J., Curstedt T., Robertson B. The proteins of the surfactant system. Eur Respir J. 1994 Feb;7(2):372–391. doi: 10.1183/09031936.94.07020372. [DOI] [PubMed] [Google Scholar]
- Johansson J., Szyperski T., Curstedt T., Wüthrich K. The NMR structure of the pulmonary surfactant-associated polypeptide SP-C in an apolar solvent contains a valyl-rich alpha-helix. Biochemistry. 1994 May 17;33(19):6015–6023. doi: 10.1021/bi00185a042. [DOI] [PubMed] [Google Scholar]
- Killian J. A., Salemink I., de Planque M. R., Lindblom G., Koeppe R. E., 2nd, Greathouse D. V. Induction of nonbilayer structures in diacylphosphatidylcholine model membranes by transmembrane alpha-helical peptides: importance of hydrophobic mismatch and proposed role of tryptophans. Biochemistry. 1996 Jan 23;35(3):1037–1045. doi: 10.1021/bi9519258. [DOI] [PubMed] [Google Scholar]
- Lipp M. M., Lee K. Y., Zasadzinski J. A., Waring A. J. Phase and morphology changes in lipid monolayers induced by SP-B protein and its amino-terminal peptide. Science. 1996 Aug 30;273(5279):1196–1199. doi: 10.1126/science.273.5279.1196. [DOI] [PubMed] [Google Scholar]
- Mouritsen O. G., Bloom M. Mattress model of lipid-protein interactions in membranes. Biophys J. 1984 Aug;46(2):141–153. doi: 10.1016/S0006-3495(84)84007-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nag K., Perez-Gil J., Cruz A., Keough K. M. Fluorescently labeled pulmonary surfactant protein C in spread phospholipid monolayers. Biophys J. 1996 Jul;71(1):246–256. doi: 10.1016/S0006-3495(96)79221-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oosterlaken-Dijksterhuis M. A., Haagsman H. P., van Golde L. M., Demel R. A. Characterization of lipid insertion into monomolecular layers mediated by lung surfactant proteins SP-B and SP-C. Biochemistry. 1991 Nov 12;30(45):10965–10971. doi: 10.1021/bi00109a022. [DOI] [PubMed] [Google Scholar]
- Oosterlaken-Dijksterhuis M. A., Haagsman H. P., van Golde L. M., Demel R. A. Interaction of lipid vesicles with monomolecular layers containing lung surfactant proteins SP-B or SP-C. Biochemistry. 1991 Aug 20;30(33):8276–8281. doi: 10.1021/bi00247a024. [DOI] [PubMed] [Google Scholar]
- Pastrana-Rios B., Taneva S., Keough K. M., Mautone A. J., Mendelsohn R. External reflection absorption infrared spectroscopy study of lung surfactant proteins SP-B and SP-C in phospholipid monolayers at the air/water interface. Biophys J. 1995 Dec;69(6):2531–2540. doi: 10.1016/S0006-3495(95)80124-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pastrana B., Mautone A. J., Mendelsohn R. Fourier transform infrared studies of secondary structure and orientation of pulmonary surfactant SP-C and its effect on the dynamic surface properties of phospholipids. Biochemistry. 1991 Oct 15;30(41):10058–10064. doi: 10.1021/bi00105a033. [DOI] [PubMed] [Google Scholar]
- Pearson R. H., Pascher I. The molecular structure of lecithin dihydrate. Nature. 1979 Oct 11;281(5731):499–501. doi: 10.1038/281499a0. [DOI] [PubMed] [Google Scholar]
- Post A., Nahmen A. V., Schmitt M., Ruths J., Riegler H., Sieber M., Galla H. J. Pulmonary surfactant protein C containing lipid films at the air-water interface as a model for the surface of lung alveoli. Mol Membr Biol. 1995 Jan-Mar;12(1):93–99. doi: 10.3109/09687689509038502. [DOI] [PubMed] [Google Scholar]
- Pérez-Gil J., Nag K., Taneva S., Keough K. M. Pulmonary surfactant protein SP-C causes packing rearrangements of dipalmitoylphosphatidylcholine in spread monolayers. Biophys J. 1992 Jul;63(1):197–204. doi: 10.1016/S0006-3495(92)81582-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothschild K. J., Clark N. A. Polarized infrared spectroscopy of oriented purple membrane. Biophys J. 1979 Mar;25(3):473–487. doi: 10.1016/S0006-3495(79)85317-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Taneva S., Keough K. M. Pulmonary surfactant proteins SP-B and SP-C in spread monolayers at the air-water interface: II. Monolayers of pulmonary surfactant protein SP-C and phospholipids. Biophys J. 1994 Apr;66(4):1149–1157. doi: 10.1016/S0006-3495(94)80896-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vaknin D., Kjaer K., Als-Nielsen J., Lösche M. Structural properties of phosphatidylcholine in a monolayer at the air/water interface: Neutron reflection study and reexamination of x-ray reflection measurements. Biophys J. 1991 Jun;59(6):1325–1332. doi: 10.1016/S0006-3495(91)82347-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vandenbussche G., Clercx A., Curstedt T., Johansson J., Jörnvall H., Ruysschaert J. M. Structure and orientation of the surfactant-associated protein C in a lipid bilayer. Eur J Biochem. 1992 Jan 15;203(1-2):201–209. doi: 10.1111/j.1432-1033.1992.tb19848.x. [DOI] [PubMed] [Google Scholar]
- Venyaminov SYu, Kalnin N. N. Quantitative IR spectrophotometry of peptide compounds in water (H2O) solutions. II. Amide absorption bands of polypeptides and fibrous proteins in alpha-, beta-, and random coil conformations. Biopolymers. 1990;30(13-14):1259–1271. doi: 10.1002/bip.360301310. [DOI] [PubMed] [Google Scholar]
- Wang Z., Gurel O., Baatz J. E., Notter R. H. Acylation of pulmonary surfactant protein-C is required for its optimal surface active interactions with phospholipids. J Biol Chem. 1996 Aug 9;271(32):19104–19109. doi: 10.1074/jbc.271.32.19104. [DOI] [PubMed] [Google Scholar]
- Wang Z., Hall S. B., Notter R. H. Roles of different hydrophobic constituents in the adsorption of pulmonary surfactant. J Lipid Res. 1996 Apr;37(4):790–798. [PubMed] [Google Scholar]
- Weaver T. E., Whitsett J. A. Function and regulation of expression of pulmonary surfactant-associated proteins. Biochem J. 1991 Jan 15;273(Pt 2):249–264. doi: 10.1042/bj2730249. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wiener M. C., Suter R. M., Nagle J. F. Structure of the fully hydrated gel phase of dipalmitoylphosphatidylcholine. Biophys J. 1989 Feb;55(2):315–325. doi: 10.1016/S0006-3495(89)82807-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang Y. P., Lewis R. N., Hodges R. S., McElhaney R. N. Peptide models of helical hydrophobic transmembrane segments of membrane proteins. 2. Differential scanning calorimetric and FTIR spectroscopic studies of the interaction of Ac-K2-(LA)12-K2-amide with phosphatidylcholine bilayers. Biochemistry. 1995 Feb 21;34(7):2362–2371. doi: 10.1021/bi00007a032. [DOI] [PubMed] [Google Scholar]
- van Stokkum I. H., Linsdell H., Hadden J. M., Haris P. I., Chapman D., Bloemendal M. Temperature-induced changes in protein structures studied by Fourier transform infrared spectroscopy and global analysis. Biochemistry. 1995 Aug 22;34(33):10508–10518. doi: 10.1021/bi00033a024. [DOI] [PubMed] [Google Scholar]
