Solid state NMR - Chapter 13, on web site: http://www.chem.ubc.ca/faculty/straus/c518_09.html A) Introduction i) Challenges of solid state ii) What can we study? iii) Review of NMR interactions B) Averaging – Magic angle sample spinning C) Polarization transfer - CP
34
Embed
Solid state NMR - University of British Columbia · Solid state NMR - Chapter 13, on web site: . A) Introduction i) Challenges of solid state ii) What can we study?
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Solid state NMR
- Chapter 13, on web site: http://www.chem.ubc.ca/faculty/straus/c518_09.html
A) Introductioni) Challenges of solid stateii) What can we study?iii) Review of NMR interactions
Solid State: 1H ca. 100 Hz13C ca. 100 Hz15N ca. 40 Hz
Oriented Methods
Solution State: 1H 12-25 Hz13C 5-15 Hz15N 4-7 Hz
Solid State: 1H ca. 1000 Hz13C ca. 300 Hz15N ca. 300 Hz
So why bother with solid state NMR?
if resolution is poor and (as we will see) the theory is complex!
Solid State NMR of Membrane Proteins
1) Membrane proteins constitute 20-40%of the proteins encoded by knowngenomes and are important drug targets (e.g. dopamine receptors, ABCtransporters)
YET
Only 368 out of a total of 20057 (1.8%)structures determined and deposited in the Protein Databank are of membraneprotein structures
STRUCTURAL INFORMATION IS NEEDED TO GAIN INSIGHT INTO FUNCTION
Recent developments in solid stateNMR have made it possible to undertake structural studies of peptidesand proteins.
Hagfish slime is 99.996% seawater, 0.002% mucin (glycoprotein) and 0.002%protein fibre. The fibres were hypothesized to contain both rigid and mobileregions. 13C spectra collected with and without cross-polarization show verydifferent carbonyl carbon lineshapes, supporting the two-phase model for thefibres.
CPBloch decay
Bloch decay spectra clearly show a sharp feature in the carbonyl region,while CP spectraclearly show a broad component.
Solution or solid?
Ubiquitin
1998
Straus, S.K. et al. 1998 J. Biomol. NMR, 12, 39-50.
2004
180 140 100 60 20
Igumenova, T.I. et al. 1998 JACS 126, 6720-27; ibid, 5323-31.