Investigation of Chiral Molecular Micelles by NMR Spectroscopy and Molecular Dynamics Simulation

Abstract

NMR spectroscopy and Molecular Dynamics (MD) simulation analyses of the chiral molecular micelles poly-(Sodium Undecyl-(L,L)-Leucine-Valine) (poly-SULV) and poly-(Sodium Undecyl-(L,L)-Valine-Leucine) (poly-(SUVL)) are reported. Both molecular micelles are used as chiral selectors in electrokinetic chromatography and each consists of covalently linked surfactant chains with chiral dipeptide headgroups. To provide experimental support for the structures from MD simulations, NOESY spectra were used to identify protons in close spatial proximity. Results from the NOESY analyses were then compared to radial distribution functions from MD simulations. In addition, the hydrodynamic radii of both molecular micelles were calculated from NMR-derived diffusion coefficients. Corresponding radii from the MD simulations were found to be in agreement with these experimental results. NMR diffusion experiments were also used to measure association constants for polar and non-polar binaphthyl analytes binding to both molecular micelles. Poly (SUVL) was found to bind the non-polar analyte enantiomers more strongly, while the more polar analyte enantiomers interacted more strongly with poly(SULV). MD simulations in turn showed that poly(SULV) had a more open structure that gave greater access for water molecules to the dipeptide headgroup region.

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K. F. Morris, E. J. Billiot, F. H. Billiot, K. B. Lipkowitz, W. M. Southerland and Y. Fang, "Investigation of Chiral Molecular Micelles by NMR Spectroscopy and Molecular Dynamics Simulation," Open Journal of Physical Chemistry, Vol. 2 No. 4, 2012, pp. 240-251. doi: 10.4236/ojpc.2012.24032.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] T. J. Ward and K. D. Ward, “Chiral Separations: Fundamental REVIEW,” Analytical Chemistry, Vol. 82, No. 12, 2010, pp. 4712-4722.
[2] J. Wang and I. M. Warner, “Chiral Separations Using Micellar Electrokinetic Capillary Chromatography and a Polymerized Chiral Micelle,” Analytical Chemistry, Vol. 66, No. 21, 1994, pp. 3773-3776.
[3] J. Wang and I. M. Warner, “Combined Polymerized Chiral Micelle and γ-Cyclodextrin for Chiral Separation in Capillary Electrophoresis,” Journal of Chromatography, A, Vol. 711, No. 2, 1995, pp. 297-304.
[4] S. A. Shamsi and I. M. Warner, “Improved Chiral Separations Using a Polymerized Dipeptide Anionic Chiral Surfactant in Electrokinetic Chromatography:? Separations of Basic, Acidic, and Neutral Racemates,” Analytical Chemistry, Vol. 69, No. 15, 1997, pp. 2980-2987.
[5] E. J. Billiot, K. Macossay, S. A. Shamsi and I. M. Warner, “Chiral Separations Using Dipeptide Polymerized Surfactants:? Effect of Amino Acid Order,” Analytical Chemistry, Vol. 70, No. 7, 1998, pp. 1375-1381.
[6] E. J. Billiot, R. A. Agbaria, S. A. Shamsi and I. M. Warner, “Amino Acid Order in Polymeric Dipeptide Surfactants:? Effect on Physical Properties and Enantioselectivity,” Analytical Chemistry, Vol. 71, No. 7, 1999, pp. 1252-1256.
[7] E. J. Billiot, S. Thibodeaux, S. A. Shamsi and I. M. Warner, “Evaluating Chiral Separation Interactions by Use of Diastereomeric Polymeric Dipeptide Surfactants,” Analytical Chemistry, Vol. 71, No. 18, 1999, pp. 4044-4049.
[8] H. H. Yarabe, S. A. Shamsi and I. M. Warner, “Characterization and Thermodynamic Studies of the Interactions of Two Chiral Polymeric Surfactants with Model Substances:? Phenylthiohydantoin Amino Acids,” Analytical Chemistry, Vol. 71, No. 18, 1999, pp. 3992-3999.
[9] E. J. Billiot and I. M. Warner, “Examination of Structural Changes of Polymeric Amino Acid-Based Surfactants on Enantioselectivity:? Effect of Amino Acid Order, Steric Factors, and Number and Position of Chiral Centers,” Analytical Chemistry, Vol. 72, No. 8, 2000, pp. 1740-1748.
[10] H. H. Yarabe, E. J. Billiot and I. M. Warner, “Enantiomeric Separations by use of Polymeric Surfactant Electrokinetic Chromatography,” Journal of Chromatography A, Vol. 875, No. 1, 2000, pp. 179-206.
[11] C. Akbay, N. L. Gill, R. A. Agbaria and I. M. Warner, “Copolymerized Polymeric Surfactants: Characterization and Application in Micellar Electrokinetic Chromatography,” Electrophoresis, Vol. 24, No. 24, 2003, pp. 4209-4220.
[12] C. Akbay, R. A. Agbaria and I. M. Warner, “Monomeric and Polymeric Anionic Gemini Surfactants and Mixed Surfactant Systems in Micellar Electrokinetic Chromatography Part II: Characterization of Chemical Selectivity Using Two Linear Solvation Energy Relationship Models,” Electrophoresis, Vol. 26, No. 3, 2005, pp. 426-445.
[13] S. A. Rizvi and S. A. Shamsi, “Polymeric Alkenoxy Amino Acid Surfactants: IV: Effects of Hydrophobic Chain Length and Degree of Polymerization of Molecular Micelles on Chiral Separation of β-Blockers,” Electrophoresis, Vol. 26, No. 21, 2005, pp. 4172-4186.
[14] S. A. Rizvi and S. A. Shamsi, “Polymeric Alkenoxy Amino Acid Surfactants: V. Comparison of Carboxylate and Sulfate Head Group Polymeric Surfactants for Enantioseparation in MEKC,” Electrophoresis, Vol. 28, No. 11, 2007, pp. 1762-78.
[15] K. Otsuka and S. Terabe, “Enantiomer Separation of Drugs by Micellar Electrokinetic Chromatography using Chiral Surfactants,” Journal of Chromatography A, Vol. 875, No. 1-2, 2000, pp. 163-178.
[16] C. P. Palmer and S. Terabe, “Micelle Polymers as Pseudostationary Phases in MEKC:? Chromatographic Performance and Chemical Selectivity,” Analytical Chemistry, Vol. 69, No. 10, 1997, pp. 1852-1860.
[17] S. A. Shamsi, B. C. Valle, F. H. Billiot and I. M. Warner, “Polysodium N-Undecanoyl-l-Leucylvalinate:? A Versatile Chiral Selector for Micellar Electrokinetic Chromatography,” Analytical Chemistry, Vol. 75, No. 3, 2003, pp. 379-387.
[18] A. D. MacKerell Jr., “Molecular Dynamics Simulation Analysis of a Sodium Dodecyl Sulfate Micelle in Aqueous Solution: Decreased Fluidity of the Micelle Hydrocarbon Interior,” Journal of Physical Chemistry, Vol. 99, No. 7, 1995, pp. 1846-1855.
[19] C. D. Bruce, M. L. Berkowitz, L. Perera and M. D. E. Forbes, “Molecular Dynamics Simulation of Sodium Dodecyl Sulfate Micelle in Water:? Micellar Structural Characteristics and Counterion Distribution,” Journal of Physical Chemistry B, Vol. 106, No. 15, 2002, pp. 3788-3793.
[20] S. Bogusz, R. M. Venable and R.W. Pastor, “Molecular Dynamics Simulations of Octyl Glucoside Micelles:? Structural Properties,” Journal of Physical Chemistry B, Vol. 104, No. 23, 2000, pp. 5462-5470.
[21] D. P. Tieleman, D. van der Spoel and H. J. C. Berendsen, “Molecular Dynamics Simulations of Dodecylphosphocholine Micelles at Three Different Aggregate Sizes:? Micellar Structure and Chain Relaxation,” Journal of Physical Chemistry B, Vol. 104, No. 27, 2000, pp. 6380-6388.
[22] S. Bogusz, R. M. Venable and R. W. Pastor, “Molecular Dynamics Simulations of Octyl Glucoside Micelles:? Dynamic Properties,” Journal of Physical Chemistry B, Vol. 105, No. 35, 2001, pp. 8312-8321.
[23] S. J. Marrink, D. P. Tieleman and A. E. Mark, “Molecular Dynamics Simulation of the Kinetics of Spontaneous Micelle Formation,” Journal of Physical Chemistry B, Vol. 104, No. 51, 2000, pp. 12165-12173.
[24] J. Gao, W. Ge, G. Hu and J. Li, “From Homogeneous Dispersion to Micelles A Molecular Dynamics Simulation on the Compromise of the Hydrophilic and Hydrophobic Effects of Sodium Dodecyl Sulfate in Aqueous Solution,” Langmuir, Vol. 21, No. 11, 2005, pp. 5223-5229.
[25] T. Lazaridis, B. Mallik and Y. Chen, “Implicit Solvent Simulations of DPC Micelle Formation,” Journal of Physical Chemistry B, Vol. 109, No. 31, 2005, pp. 15098-15106.
[26] B. C. Stephenson, K. Beers and D. Blankschtein, “Complementary Use of Simulations and Molecular-Thermodynamic Theory to Model Micellization,” Langmuir, Vol. 22, No. 4, 2006, pp. 1500-1513.
[27] A. Cavallo, M. Müller and K. Binder, “Formation of Micelles in Homopolymer-Copolymer Mixtures:? Quantitative Comparison between Simulations of Long Chains and Self-Consistent Field Calculations,” Macromolecules, Vol. 39, No. 26, 2006, pp. 9539-9550. doi:10.1021/ma061493g
[28] B. C. Stephenson, A. Goldsipe, K. J. Beers and D. Blankschtein, “Quantifying the Hydrophobic Effect. 2. A Computer Simulation-Molecular-Thermodynamic Model for the Micellization of Nonionic Surfactants in Aqueous Solution,” Journal of Physical Chemistry B, Vol. 111, No. 5, 2007, pp. 1045-1062.
[29] C. D. Bruce, S. Senapati, M. L. Berkowitz, L. Perera and M. D. E. Forbes, “Molecular Dynamics Simulations of Sodium Dodecyl Sulfate Micelle in Water:? The Behavior of Water,” Journal of Physical Chemistry B, Vol. 106, No. 42, 2002, pp. 10902-10907.
[30] E. J. Billiot, “Chiral Recognition with Polymerized Dipeptide Surfactants in Capillary Electrophoresis,” Ph.D. dissertation, Louisiana State University, Baton Rouge, 1998.
[31] J. K. Rugutt, E. J. Billiot and I. M. Warner, “NMR Study of the Interaction of Monomeric and Polymeric Chiral Surfactants with (R)- and (S)-1,1’-Binaphthyl-2,2’-Diyl Hydrogen Phosphate,” Langmuir, Vol. 16, No. 7, 2000, pp. 3022-3029.
[32] K. F. Morris, B. A. Becker, B. C. Valle, I. M. Warner and C.K. Larive, “Use of NMR Binding Interaction Mapping Techniques to Examine Interactions of Chiral Molecules with Molecular Micelles,” Journal of Physical Chemistry B, Vol. 110, No. 35, 2006, pp. 17359-17369. doi:10.1021/jp0627224
[33] B. C. Valle, K. F. Morris, K. A. Fletcher, V. Fernand, D. M. Sword, S. Eldridge, C. K. Larive and I. M. Warner, “Understanding Chiral Molecular Micellar Separations Using Steady-State Fluorescence Anisotropy, Capillary Electrophoresis, and NMR,” Langmuir, Vol. 23, No. 2, 2007, pp. 425-435. doi:10.1021/la0612623
[34] S. A. Kingsbury, C. J. Ducommun, B. M. Zahakaylo, E. H. Dickinson and K. F. Morris, “NMR Characterization of 1,1’-Binaphthyl-2,2’-Diyl Hydrogen Phosphate Binding to Chiral Molecular Micelles,” Magnetic Resonance in Chemistry, Vol. 48, No. 3, 2010, pp. 184-191.
[35] M. Piotto, V. Saudek and V. Skienar, “Gradient-Tailored Excitation for Single Quantum NMR Spectroscopy of Aqueous Solutions,” Journal of Biomolecular NMR, Vol. 2, No. 6, 1992, pp. 661-665.
[36] M. Lin, D. A. Jayawickrama, R. A. Rose, J. A. DelViscio and C.K. Larive, “Nuclear Magnetic Resonance Spectroscopic Analysis of the Selective Complexation of the Cis and Trans Isomers of Phenylalanylproline by β-Cyclodextrin,” Analytica Chimica Acta, Vol. 307, No. 3, 1995, pp. 449-457.
[37] D. H. Wu, A. D. Chen and C. S. Johnson. Jr. “An Improved Diffusion Ordered Spectroscopy Experiment Incorporating Bipolar Gradient Pulses,” Journal of Magnetic Resonance, Vol. A115, No. 2, 1995, pp. 260-264.
[38] P. Stilbs, “Fourier Transform Pulsed-Gradient Spin-Echo Studies of Molecular Diffusion,” Progress in NMR Spectrosopy, Vol. 19, No. 1, 1987, pp. 1-45.
[39] D. A. Case, T. A. Darden, T. E. Cheatham, C. L. Simmerling, J. Wang, R. E. Duke, R. Luo, M. Crowley, R. C. Walker, W. Zhang, K. M. Merz, B. Wang, S. Hayik, A. Roitberg, G. Seabra, I. Kolossváry, K. F.Wong, F. Paesani, J. Vanicek, X. Wu, S. R. Brozell, T. Steinbrecher, H. Gohlke, L. Yang, C. Tan, J. Mongan, V. Hornak, G. Cui, D. H. Mathews, M. G. Seetin, C. Sagui, V. Babin and P. A. Kollman, “AMBER 10,” University of California, San Francisco, 2008
[40] J. Wang, P. Cieplak and P. A. Kollman, “How Well Does a Restrained Electrostatic Potential (RESP) Model Perform in Calculating Conformational Energies of Organic and Biological Molecules,” Journal of Computational Chemistry, Vol. 21, No. 12, 2000, pp. 1049-1074.
[41] U. Essmann, L. Perera, M. L. Berkowitz, T. A. Daden and L. H. Pedersen, “A Smooth Particle Mesh Ewald Method,” Journal of Chemical Physics, Vol. 103, No. 19, 1995, pp. 8577-8593.
[42] K. Wüthrich, “NMR of Proteins and Nucleic Acids,” John Wiley & Sons, Inc., New York, 1986.
[43] D. K. Wilkins, S. B. Grimshaw, V. Receveur, C. M. Dobson, J. A. Jones and L. J. Smith, “Hydrodynamic Radii of Native and Denatured Proteins Measured by Pulse Field Gradient NMR Techniques,” Biochemistry, Vol. 38, No. 50, 1999, pp. 16424-16431.
[44] C. H. Cho, J. Urquidi, S. Singh and G. W. Robinson, “Thermal Offset Viscosities of H2O, D2O, and T2O,” Journal of Physical Chemistry B, Vol. 102, No. 11, pp. 1991-1994.
[45] S. A. Rogers-Sanders, D. V. Velde and C.K. Larive, “Evaluation of NMR Diffusion Measurements for the Conformational Analysis of Flexible Peptides,” Journal of Analytical Chemistry, Vol. 369, No. 3, 2001, pp. 308-331.

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