Dynamic and 2D NMR studies on hydrogen-bonding aggregates of cholesterol in low-polarity organic solvents

Journal of Physical Chemistry B

Volumn 110, Issue 31, 2006, Pages 15205-15211

  Giordani, Cristiano ^a   Wakai, Chihiro ^a   Okamura, Emiko ^a   Matubayasi, Nobuyuki ^a   Nakahara, Masaru ^a  

^a KYOTO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

DIFFUSION; HYDROGEN BONDS; NUCLEAR MAGNETIC RESONANCE; ORGANIC SOLVENTS; WATER;

CHLOROFORM; HYDRODYNAMIC RADIUS (R); IMPURITY WATER CONCENTRATION; PULSED FIELD GRADIENT SPIN-ECHO (PGSE); SATURATED CONCENTRATIONS;

CHOLESTEROL;

EID: 33748256334     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp062607t     Document Type: Article

References (25)

1. Simons, K.; Ikonen, E. Nature 1997, 387, 569.
2. Simons, K.; Ehehalt, R. J. Clin. Invest. 2002, 110, 597.
3. Okamura, E.; Wakai, C.; Matubayasi, N.; Sugiura, Y.; Nakahara, M. Phys. Rev. Lett. 2004, 93, 248101.
4. Stilbs, P. Prog. Nucl. Magn. Reson. Spectrosc. 1987, 19, 1.
5. Wakai, C.; Nakahara, M. J. Chem. Phys. 1997, 106, 7512.
6. The modulation by spin-spin coupling is observed for diffusion measurements using nondeuterated cholesterol; however, in normal cholesterol, the position 18 is almost not affected by spin-spin coupling as we proved by the comparison of the diffusion coefficient in nondeuterated (position C18) and deuterated cholesterol (C26 and C27 methyl groups deuterated). Cholesterol deuterated at position C26 and C27 permits elimination of the spin-spin coupling effect because the two deuterons do not interfere with the others in the molecule and the interaction between them is symmetric. In addition, the number of deuterons gives us a strong NMR signal even at low concentration.
7. Bender, H. J.; Zeidler, M. D. Bunsen-Ges., Phys. Chem. 1971, 75, 236.
8. Yoshida, K.; Wakai, C.; Matubayasi, N.; Nakahara, M. J. Chem. Phys. 2005, 123, 164506.
9. Nakahara, M.; Wakai, C. Chem. Lett. 1992, 809.
10. Wilson, W. K.; Sumpter, R. M.; Warren, J. J.; Rogers, P. S.; Ruan, B.; Schoroepfer, G. J. J. Lipid Res. 1996, 37, 1529.
11. Jeannerat, D. Magn. Reson. Chem. 2000, 38, 415.
12. Tyrell, H. J. V.; Harris, K. R. Diffusion in Liquids; Cambridge University Press: London, 1984.
13. Viswanath, D. S.; Natarajan, G. Data Book on the Viscosity of Liquids; Hemisphere: New York, 1989.
14. Saleh, M. A.; Akhtar, S.; Begum, S.; Shamsuddin, M. A.; Begum, S. K. Phys. Chem. Liq. 2004, 42, 615.
15. Tu, C.; Wang, W.; Liu, C.; Chou, Y. J. Chem. Eng. Data 2000, 45, 450.
16. Hoyuelos, F. J.; Garcia, B. R.; Ibeas, A. S.; Leal, J. M. J. Chem. Soc., Faraday Trans. 1996, 92, 219.
17. The long molecular axis is estimated to be 16 and the short one 3.8 Å according to a molecular model (CS ChemDraw). The average radius is 4.9 Å.
18. Gupta, R. K.; Suresh, K. A. Eur. Phys. J. E 2004, 14, 35.
19. Albert, B.; Bray, D.; Lewis, J.; Raft, M.; Roberts, K.; Watson, J. D. Molecular Biology of the Cell, 3rd ed.; Garland Publishing: New York, 1994.
20. 2 and its length 20 Å, the concentration of DPPC is 1.4 M.
21. The tail of the cholesterol molecule is freer to move than any other part of the molecule. In the presence or absence of aggregation, there will not be any difference in the rotational motion at position C26 and C27 because cholesterol molecules form aggregates that involve atomic positions close to the sterol skeleton, as shown by 2D NMR analysis. As can be seen in Figure 4, the peaks at position C3 and C6 are broader than those at position C26 and C27, where the C-H bond vectors are almost free to rotate.
22. Abragam, A. The Principles of Nuclear Magnetism; Oxford University: Oxford, 1961.
23. McConnell, J. The Theory of Nuclear Magnetic Relaxation in Liquids; Cambridge University: Cambridge, 1987.
24. Morrow, M. R.; Grant, C. W. M. Biophys. J. 2000, 79, 2024.
25. Brand, T.; Cabrita, E. J.; Berger, S. Prog. Nucl. Magn. Reson. Spectrosc. 2005, 46, 159.