Valine

ABSTRACT Monomolecular films of valine gramicidin A (VGA) were investigated in situ at the air-water interface by x-ray reflectivity and x-ray grazing incidence diffraction as well as polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS). These techniques were combined to obtain information on the secondary structure and the orientation of VGA and to characterize the shoulder observed in its pi-A isotherm. The thickness of the film was obtained by x-ray reflectivity, and the secondary structure of VGA was monitored using the frequency position of the amide I band. The PM-IRRAS spectra were compared with the simulated ones to identify the conformation adopted by VGA in monolayer. At large molecular area, VGA shows a disordered secondary structure, whereas at smaller molecular areas, VGA adopts an anti-parallel double-strand intertwined beta5.6 helical conformation with 30 deg orientation with respect to the normal with a thickness of 25 Angstrom. The interface between bulk water and the VGA monolayer was investigated by x-ray reflectivity as well as by comparing the experimental and the simulated PM-IRRAS spectra on D^sub 2^O and H^sub 2^O, which suggested the presence of oriented water molecules between the bulk and the monolayer.

INTRODUCTION

We are indebted to the Natural Sciences and Engineering Research Council of Canada for financial support. H.L. also thanks Syndicat des professuers et des professeures de l'Universite du Quebec a Trois-Rivieres and Fondation de l'Universite du Quebec a Trois-Rivieres for their financial support. C.S. is a chercheur-boursier national of the Fonds de la recherche en sante du Quebec. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under contract W-7405-Eng-82. The work at Ames was supported by the Director for Energy Research, Office of Basic Energy Sciences.

REFERENCES

Als-Nielsen, J., and K. Kjaer. 1989. Phase transitions in soft condensed matter. Proc. NATO Adv. Study Inst. 211:113-138.

Als-Nielsen, J., and P. S. Pershan. 1983. Synchrotron x-ray diffraction study of liquid surface. Nuclear Instrum. Methods. 208:545-548.

Bertie, J. E., M. K. Ahmed, and H. H. Eysel. 1989. Infrared intensities of liquids. V. Optical and dielectric constants, integrated intensities, and dipole moment derivatives of H20 and D20 at 22'C. J. Phys. Chem. 93:2210-2218.

Blaudez, D., F. Boucher, T. Buffeteau, B. Desbat, M. Grandbois, and C. Salesse. 1999. Determination of the anisotropic optical constants of bacteriorhodopsin in the mid infrared. Appl. Spectrosc. 53:1299-1304.

Blaudez, D., T. Buffeteau, J. C. Cornut, B. Desbat, N. Escafre, M. Pezolet, and J. M. Turlet. 1993. Polarization-modulated FT-IR spectroscopy of a spread monolayer at the air-water interface. Appl. Spectrosc. 47: 869-874.

Blaudez, D., J-M. Turlet, J. Dufourcq, D. Bard, T. Buffeteau, and B. Desbat. 1996. Investigation at the air/water interface using polarization modulation IR spectroscopy. J. Chem. Soc. Faraday Trans. 92:525-530.

Buffeteau, T., D. Blaudez, E. Pere, and B. Desbat. 1999. Optical constant determination in the infrared of uniaxially oriented monolayers from transmittance and reflectance measurements. J. Phys. Chem. B. 103: 5020-5027.

Castano, S., B. Desbat, and J. Dufourcq. 2000. Ideally amphipathic beta-- sheeted peptides at interfaces: structure, orientation, affinities for lipids and hemolytic activity of (KL)(m)K peptides. Biochim. Biophys. Acta. 1463:65-80.

Castano, S., B. Desbat, M. Laguerre, and J. Dufourcq. 1999. Structure, orientation and affinity for interfaces and lipids of ideally amphipathic lyric LiKj(i = 2j) peptides. Biochim. Biophys. Acta. 1416:176-194.

Cornut, I., B. Desbat, J. M. Turlet, and J. Dufourcq. 1996. 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. 70:305-312.

Dhathathreyan, A., U. Baumann, A. Muller, and D. Mobius. 1988. Characterization of complex gramicidin monolayers by light reflection and Fourier transform infrared spectroscopy. Biochim. Biophys. Acta. 944: 265-272.

Dieudonne, D., R. Mendelsohn, R. Farid, and C. Flash. 2001. Secondary structure in lung surfactant SP-B peptides: IR and CD studies of bulk and monolayer phases. Biochim. Biophys. Acta. 1511:99-112.

Dluhy, R., and R. Mendelsohn. 1988. Emerging techniques in biophysical FT-IR. Anal. Chem. 60:269A-278A.

Dluhy, R., K. Reilly, R. Hunt, M. Mitchell, A. Mautone, and R. Mendelsohn. 1989. Infrared spectroscopic investigations of pulmonary surfactant: surface film transitions at the air-water interface and bulk phase thermotropism. Biophys. J. 56:1173-1181.

Ducharme, D., D. Vaknin, M. Paudler, C. Salesse, H. Riegler, and H. Mohwald. 1996. Surface properties of valine-gramicidin A at the air/ water interface. Thin Solid Films. 284-285:90-93.

Flash, C., J. Brauner, J. Taylor, R. Baldwin, and R. Mendelsohn. 1994. 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. 67:402-410.

Flash, C., F. Prendergast, and R. Mendelsohn. 1996. Infrared reflection-- absorption of melittin interaction with phospholipid monolayers at the air/water interface. Biophys. J. 70:539-546.

Fukuto, M., K. Penanen, R. K. Heilmann, P. S. Pershan, and D. Vaknin, 1997. C60-propylamine adduct monolayers at the gas/water interface: a Brewster angle microscopy and x-ray scattering study. J. Chem. Phys. 107:5531-5546.

Gallant, J., B. Desbat, D. Vaknin, and C. Salesse. 1998. Polarization-- modulated infrared spectroscopy and x-ray reflectivity of photosystem II core complex at the gas-water interface. Biophys. J. 75:2888-2899.

Gidalevitz, D., Z. Huang, and S. Rice. 1999. Protein folding at the air-water interface studied with x-ray reflectivity. Proc. Natl. Acad. Sci. U.S.A. 96:2608-2011.

Goormaghtigh, E., V. Cabiaux, and J. M. Ruysschaert. 1990. Secondary structure and dosage of soluble and membrane proteins by attenuated total reflection Fourier-transform infrared spectroscopy on hydrated films. Eur. J. Biochem. 193:409-420.

Grandbois, M., B. Desbat, and C. Salesse. 2000. Monitoring of phospholipid monolayer hydrolysis by phospholipase A2 by use of polarization-- modulated Fourier transform infrared spectroscopy. Biophys. Chem. 88:127-135.

Haas, H., G. Brezesinski, and H. Mohwald. 1995. X-ray diffraction of a protein crystal anchored at the air/water interface. Biophys. J. 68: 312-314.

Hladky, S. B., and D. A. Haydon. 1972. Ion transfer across lipid membranes in the presence of gramicidin A. I. Studies of the unit conductance channel. Biochim. Biophys. Acta. 274:294-312.

Kemp, G., and C. Wenner. 1976. Solution, interfacial, and membrane properties of gramicidin A. Arch. Biochem. Biophys. 176:547-555. Killian, J. A. 1992. Gramicidin and gramicidin-lipid interactions. Biochim. Biophys. Acta. 1113:391-425.

Langs, D. A. 1988. Three-dimensional structure at 0.86 A of the uncomplexed form of the transmembrane ion channel peptide gramicidin A. Science. 241:188-191.

Lavoie, H., J. Gallant, M. Grandbois, D. Blaudez, B. Desbat, F. Boucher, and C. Salesse. 1999. The behavior of membrane proteins in monolayers at the gas-water interface: comparison between photosystem II, rhodopsin and bacteriorhodopsin. Mater. Sci. Eng. C. 10:147-154.

Lenne, P. F., B. Berge, A. Renault, C. Zakri, C. Venien-Bryan, S. Courty, F. Balavoine, W. Bergsma-Schutter, A. Brisson, G. Grubel, N. Boudet, 0. Konovalov, and J. F. Legrand. 2000. Synchrotron radiation diffraction from two-dimensional protein crystals at the air/water interface. Biophys. J. 79:496-500.

LoGrasso, P. V., F. D. Moll, and T. A. Cross. 1988. Solvent history dependence of gramicidin A conformations in hydrated lipid bilayers. Biophys. J. 54:259-267.

MacRitchie, F. 1978. Proteins at interfaces. Adv. Protein Chem. 32: 283-326.

MacRitchie, F. 1986. Spread monolayers of proteins. Adv. Colloid Interface Sci. 25:341-385.

Mau, N. D., P. Daumas, D. Lelievre, Y. Trudelle, and F. Heitz. 1987. Linear gramicidins at the air-water interface. Biophys. J. 51:843-845.

Naik, V. M., and S. Krimm. 1986. Vibrational analysis of the structure of gramicidin A. I. Normal mode analysis. Biophys. J. 49:1131-1145.

Quist, P, O. 1998. 13C solid-state NMR of gramicidin A in a lipid membrane. Biophys. J. 75:2478-2488.

Ries, H. E., and H. Swift. 1987. Monolayers of two transmembrane channel formers and an ionophore. J. Colloid Interface Sci. 117:584-588. Salemme, F. R. 1988. Structural polymorphism in transmembrane channels. Science. 241:145-230.

Sarges, R., and B. Witkop. 1965. Gramicidin A. V. The structure of valine-- and isoleucine-gramicidin A. J. Am. Chem. Soc. 87:2011-2020. Tournois, H., P. Gieles, R. Demel, J. de Gier, and B. de Kruijff. 1989.

Interfacial properties of gramicidin and gramicidin-lipid mixtures measured with static and dynamic monolayer techniques. Biophys. J. 55: 557-569.

Ulrich, W. P., and H. Vogel. 1999. Polarization-modulated FTIR spectroscopy of lipid/gramicidin monolayers at the air/water interface. Biophys. J. 76:1639-1647.

Urban, B. W., S. B. Hladky, and D. A. Haydon. 1978. The kinetics of ion movements in the gramicidin channel. Fed Proc. 37:2628-2632. Urban, B. W., S. B. Hladky, and D. A. Haydon. 1980. Ion movements in

gramicidin pores: an example of single-file transport. Biochim. Biophys. Acta. 602:331-354.

Verclas, S. A., P. B. Howes, K. Kjaer, A. Wurlitzer, M. Weygand, G. Buldt, N. A. Dencher, and M. Losche. 1999. X-ray diffraction from a single layer of purple membrane at the air/water interface. J. MoL Biol. 287:837-843.

Wallace, B. A. 1986. Structure of gramicidin A. Biophys. J. 49:295-306. Wallace, B. A. 1998. Recent advances in the high resolution structures of bacterial channels: gramicidin A. J. Struct. BioL 121:123-141.

Wallace, B. A., and K. Ravikumar. 1988. The gramicidin pore: crystal structure of cesium complex. Science. 241:182-187.

Wu, F., C. Flach, B. Seaton, T. Mealy, and R. Mendelsohn. 1999. Stability of annexin V in ternary complexes with Ca" and anionic phospholipids: IR studies of monolayer and bulk phases. Biochemistry. 38:792-799.

Hugo Lavoie,* Daniel Blaudez,+ David Vaknin,++ Bernard Desbat,(sec) Benjamin M. Ocko,(para) and Christian Salesse*

*Departement de Chimie-Biologie, Universite du Quebec a Trois-Rivibres, Trois-Rivibres, Trois-Rivieres, Quebec G9A 51-17, Canada; +Centre de Physique Moleculaire Optique et Hertzienne and (sec)Laboratoire de Physico-Chimie Moleculaire, Universite Bordeaux 1, 33405 Talence, France; ++Ames Laboratory and Department of Physics, Iowa State University, Ames, Iowa 50011 USA; and (para)Brookhaven National Laboratory, Department of Physics, Upton, New York 11973 USA

Submitted December 3, 2001 and accepted for publication August 13, 2002.

Address reprint requests to Dr. Christian Salasse, Departement de Chimie-- Biologie, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, Quebec Canada, G9A 5H7. Tel.: 819-376-5011; Fax: 819-376-5057; E-mail: christian_salesse@uqtr.ca.

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