药物所研究生课件 蛋白质化学讲义.ppt

Stereo Structure Determination UV (Ultraviolet) spectroscopy CD (Circular Dichroism) Florescence IR (Infrared) and Raman spectroscopy AFM (Atomic Force Microscopy) ESR (Electron Spin Resonance) X-ray diffraction (crystallography) MS (Mass spectrometry) Multidimensional NMR (Nuclear Magnetic Resonace) spectroscopy Spectroscopic Methods in Structural Analysis of Peptides(1) UV: different absorbance strength and band wavelength for a-helix and b-sheet. Spectroscopic Methods in Structural Analysis of Peptides(2) CD: (1)190-240 nm: characteristic bands for peptide chain conformation (a- helix, random coli, and b-sheet as well) (2)240-300nm: side chain interactions (3)300nm: for heme and metal containing peptides Spectroscopic Methods in Structural Analysis of Peptides(3) Fluorescence: Tryptophan can emit fluorenscence; A fluorescence probe (such as GFP) can also be added. The latter one was most useful in structural determination. Spectroscopic Methods in Structural Analysis of Peptides(4) IR or Raman: In IR, 1660 cm-1 was band I of the amide bond which is sensitive to hydrogen bonding. Raman is frequently applied to determine peptide conformation in water solution. Spectroscopic Methods in Structural Analysis of Peptides(5) AFM: 1-2 nm resolution, better resolution than optical microscopy; retain conformation better than electronic microscopy Spectroscopic Methods in Structural Analysis of Peptides(6) ESR: radical and unpaired electron Spectroscopic Methods in Structural Analysis of Peptides(7) X-ray crystallography: |Fhkl| data collection, ahkl determination, optimization of ahkl, electronic density map and initial structure, optimization of structure. Spectroscopic Methods in Structural Analysis of Peptides(8) MS: FAB, ESI, MALDI-TOF Multidimensional NMR: (1)data collection: COSY. DQF-COSY. Relay-COSY, TOCSY, NOESY, ROESY (2)Spin system and NMR signal assignment (3)Secondary structure determination (4)Establishment of 3D structure in solution (5)St