1 / 28

Symposium of Frontiers in NMR

核磁共振前沿研討會 慶祝葉朝輝教授榮膺中國科學院院士. Symposium of Frontiers in NMR Celebration of Professor Ye Chaohui for His Induction into The Chinese Academy of Sciences. 生物固態 NMR 進展： 奇半整數四極核之應用 Recent Development in Biological Solid State NMR：Applications of Odd-Half-Integer Quadrupolar Nuclei. 國立中山大學化學系

meena
Download Presentation

Symposium of Frontiers in NMR

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 核磁共振前沿研討會 慶祝葉朝輝教授榮膺中國科學院院士 Symposium of Frontiers in NMR Celebration of Professor Ye Chaohui for His Induction into The Chinese Academy of Sciences

  2. 生物固態NMR進展：奇半整數四極核之應用Recent Development in Biological Solid State NMR：Applications of Odd-Half-Integer Quadrupolar Nuclei 國立中山大學化學系 Department of Chemistry, National Sun Yat-sen University 丁尚武 Shangwu Ding 2002年4月8日於武漢 Wuhan April 8, 2002

  3. Contents 1. Introduction 2. Principle of MQMAS 3. Example: ATP sodium salts 4. Summary 5. Concluding Remarks Acknowledgments

  4. Introduction The era of structural biology Why Solid state NMR for biomolecules? ----Liquid state NMR: fast motion ----X-ray: single crystal ----Microimaging: insufficient resolution ----Others: invisible to bulk spins

  5. Brief History • Before 1980: unborn • 1980s (S.J.Opella): Small molecules; Individual amino acids • 1990s: C-13 chemical shift tensors of all 20 amino acids (Chaohui Ye et al., 1993.) N-15 CSA tensors amino acids: incomplete N-15 CSA tensors of four bases (ATGC), (D.M.Grant et al., 1998. Polypeptides and proteins (R.Griffin 1990, T.A.Cross et al., 1996; S.J.Opella et al., 1995, G.Drobny et al., 1995; R.Tycko et al., 1999, M.Hong, 1998; etc.) Ion-biomolecule interactions (J.Shaefer, 1997; A.E.McDermott, R.E.Wasylishen 1995; G.Wu; 1998 etc.)

  6. Major Missions • Membrane-bound peptides and proteins • Metalloproteins • Ligand-receptor interactions • Nucleic acids (DNA, RNA) • Enzyme reaction mechanisms • Protein folding/unfolding/misfolding

  7. What Is A Quadrupolar Spin? S=1/2 S=3/2 S=5/2

  8. Where zinc is bound with the protein?

  9. Figure 1 (a) Experimental 67Zn NMR spectrum of XPA-MBD at 9.4 T and 25 K, with 25 Hz conventional line boadening (LB), (b) data from part a apodized with 5 Hz conventional and 1 kHz matched LB and zero filled to double the echo spacing, and (c) simulation utilizing parameters described in the text with 25 Hz conventional and 1.5 kHz matched LB. All spectra are conventionally zero filled to 512k points.

  10. COOL PROBE Sears (left), Ellis (center), and Lipton hold the probe they developed for NMR analysis of zinc metalloproteins. The researchers climbed the foothills of Rattlesnake Mountain, Washington, outside their lab, to take this photo for C&EN.

  11. MQMAS Principle (I)

  12. Second order quadrupolar broadening HB HB+HQ(1) HB+HQ(1)+HQ(2) Under rapid magic angle spinning (MAS):

  13. Coordinate Systems Molecular Frame (PAS) Rotor Frame Lab Frame

  14. MQMAS Principle (II) Redefining t1’=t1|C4S(I1)|/C4S(1/2) + FT F1: Isotropic frequenciesF2: MAS spectra

  15. MQMAS Pulse Sequence Excitation Evolution Conversion Acquisition P1 t1 P2 t2 L.Frydman, J.S.Harwood, JACS 117,5367(1995) MQC SQC θM θM

  16. Quantification of the MQMAS Spectra Purpose: To ensure the intensities of an MQMAS spectral peak to be proportional to site population. Strategy: Obtain an MQMAS spectrum with optimal experimental settings; Calculate the quadrupolar tensors from the isotropic positions and MAS slices; Use the values of the quadrupolar tensors and experimental parameters to compute the excitation and conversion efficiencies for each site; Obtain the intensity correction factor for each site according to these efficiencies. Ding and McDowell, Chem. Phys. Lett. 307, 215 (1999). Quantitative spectrum.

  17. Compound Experimental population ratio Corrected population ratio Na2HPO4 1.00:0.92:1.48 1:0;1.05:1.75 Na3C6H5O7．2H2O 1.00:0.72:0.52 1.00:0.96:0.94 Na3SO3 1.00:0.81:1.75 1.00:0.98:2.1 Quantification of MQMAS Spectra The lattice site population ratios for some representative compounds S.Ding,C.A.McDowell, Chem. Phys. Lett. 307, 215 (1999).

  18. Incomplete Statistics of Applications of MQMAS Glasses; Salts; Aluminatophosphates; Zeolites; Silicates; Minerals; Aluminas; Aluminates; Modified aluminas; Metal ions in biological compounds ….

  19. Structure of Sodium ATP

  20. Na-23 MAS Spectra of Sodium ATP

  21. Na-23 MQMAS Spectra of Sodium ATP at Two Different Fields (4.7T) (9.4T)

  22. Quadrupolar parameters can be evaluated from MQMAS and MAS spectra

  23. 展望及建議Concluding Remarks • 放鬆對樣品的要求 More tolerant to samples • 更好地利用質子 Better use of protons • 更多地利用四極核 More use of quadrupolar nuclei • 動態研究 Dynamics • 理論方法，計算模擬 Theory and computation • 影像技術(量子分子顯微術？) Imaging techniques (Quantum Molecular Microscopy？) • 應用 More extensive applications 強烈推薦：最好的學位論文方向或博士後研究課題 I strongly recommend this area which represents the most fortunate direction for thesis work and postdoctoral research

More Related