INVESTIGATION OF TEMPERATURE DEPENDENCE OF D2O SOLUTIONS BY 400 MHZ NMR

Abstract

The rate of water proton relaxation of protein solutions were studied in the presence and absence of the paramagnetic ions[gadolinium (III), manganese (II), chromium (III), iron (III), nickel (II), copper (II), and cobalt (II)]   in the previous studies. However, these studies were carried out rather at low frequencies. Therefore, studying of temperature dependence of relaxation rates for absence and presence of 2 % albumin in pure D₂O by 400 MHz will be a novelty.

In this study, T₁ and T₂ relaxation ratios of D₂O and 0.1 H₂O/0.9D₂O solutions were investigated with respect to temperature for pure and  for constant  albumin  concentration(2%). The experiments were carried out by using Bruker Avance 400 MHz NMR. Inversion Recovery (180-τ-90) pulse step were used for T₁, whereas Carr-Purcell-Meiboom-Gill pulse step were used for T₂.  The experiments were performed for temperature range of 20°C-40°C by using automatic temperature control unit.

1/T₁ and 1/T₂ decrease linearly with increasing temperature for pure D₂O solutions. However, for 0.1H₂O/0.9D₂O solutions, the relaxation rates of T₁ increase with increasing temperature while T₂ decreases with increasing temperature. The decrease in both relaxation rates of the D₂O solution with respect to the increased temperature suggests that relaxation is due to spin relaxation interaction. Increasing of relaxation rates with the increasing temperature, in the presence of albumin demonstrates the validity of the dipolar mechanism

Keywords

• NMR,T1,T2,Relaxation,Albumin

References

1. 1] Cistola, D.P., Small, D.M.: J. Clin. İnvest. 87 (1991), 1431-1441.
2. [2] Fasano, et al, IUBMB Life 12 (2005), 787-796.
3. [3] Sulkowska, et al, The competition of drugs to serum albumin in combination chemotherapy: NMR study J. Mol. Struct. 744 (2005), 781-787.
4. [4] Koenig S.H, Schillinger WE. Nuclear magnetic relaxation dispersion in protein solutions. I. Apotransferrin. J Biol Chem., 244 (1969, 3283-89.
5. [5] Gösch, L., Noack, F.L., NMR relaxation investigation of water mobility in aqueous bovine serum albumin solutions, Biochim. Biophys. Acta. 453 (1976), 218-232.
6. [6] Hallenga, K., Koenig, S.H., Protein rotational relaxation as studied by solvent 1H and 2H magnetic relaxation, Biochemistry 15 (1976), 4255-4264.
7. [7] Oakes, J., Protein hydration. Nuclear magnetic resonance relaxation studies of the state of water in native bovine serum albumin solutions, J. Chem. Soc. Farad. Trans. 72 (1976) 216- 227.
8. [8] Gallier, et al, 1H- and 2H-NMR study of bovine serum Albumin solutions, Biochim. Biophys. Acta. 915 (1987) 1-18.

9. [9] Koenig, S.H., Brown, R.D., A molecular theory of relaxation and magnetization transfer: Application to cross-linked BSA, a model for tissue, Magn. Reson. Med. 30 (1993), 685-695.
10. [10] Koenig, et al., Magnetization transfer in cross-linked bovine serum albumin solutions at 200 MHz: A model for tissue, Magn. Reson. Med. 29(3) (1993), 311-316.
11. [11] Koenig, S.H., Classes of hydration sites at protein-water interfaces: The source of contrast in magnetic resonance imaging, Biophys. J. 69 (1995), 593-603.
12. [12] Bryant, R.G., The dynamics of water protein interactions, Ann. Rev. Biophys. Biomol. Struct. 25 (1996), 29-53.
13. [13] V.P. Denisov, et al., Using buried water molecules to explore the energy landscape of proteins, Nat. Struct. Biol. 3 (1996), 505–509.
14. [14] Bertini, et al., 1H NMRD profiles of diamagnetic proteins: a model-free analysis, Magn. Reson. Chem. 38 (2000), 543-550.
15. [15] Kiihne, S., Bryant, R.G., Protein-Bound Water Molecule Counting by Resolution of 1H Spin-Lattice Relaxation Mechanisms, Biophys. J. 78 (2000), 2163-2169.
16. [16] Denisov, V.P., Halle, B., Hydrogen Exchange Rates in Proteins from Water 1H Transverse Magnetic Relaxation, J Am Chem Soc. 124(35) (2002), 10264-10265.
17. [17] Van-Quynh, et al., Protein reorientation and bound water molecules measured by 1H magnetic spin-lattice relaxation, Biophys. J. 84 (2003), 558-563.
18. [18] Halle, B., Protein hydration dynamics in solution: a critical survey, Philos. T. Roy. Soc. Lond. B. 359 (2004), 1207-1224.
19. [19] Bertini, et al., NMR Spectroscopic detection of protein protons and longitudinal relaxation rates between 0.01 and 50 MHz, Angew. Chem. 117 (2005), 2263-2265.
20. [20] A.Yilmaz, et al, Determination of the effective correlation time modulating 1H NMR relaxation processes of bound water in protein solutions, Magn. Reson. Imaging. 26 (2008) 254-260
21. [21] Kang MS, et al., Isolation of chitin synthetase from Saccharomyces cerevisiae. Purification of an enzyme by entrapment in the reaction product. J Biol Chem 259(23), (1984),14966-72.
22. [22] Elst et al, Subtle Prefrontal Neuropathology in a Pilot Magnetic Resonance Spectroscopy Study in Patients With Borderline, J Neuropsychiatry Clin Neurosci 13:4(2001), 511–514.
23. [23] James l. Barnhart, Robert N. Berk, Influence of Paramagnetic Ions and pH on Proton NMR Relaxation of Biologic Fluids, Invest radiol (1986), 21:132-13.
24. [24] Silvio et al., ¹H and ¹⁷O relaxometric investigations of the binding of Mn(ӀӀ) ion to human serum Albumin, Magnetıc Resonance ın chemistry 2002; 40:41-48.
25. [25] Korb, J.P, Bryant, R. G., Magnetıc Field Dependence of Proton Spin- Lattice Relaxation Times , Magnetıc Resonance ın Medıcıne, (2002), 48:21-26.
26. [26] Kruk D, Kowalewski J., Nuclear spin relaxation in paramagnetic systems (S>/=1) under fast rotation conditions, J Magn Reson. 162(2) (2003), 229-40.