The Pulse FT NMR Experiment

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The Pulse FT NMR Experiment
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Proteins Have Too Many Signals! 1H NMR Spectrum
of Ubiquitin
500 resonances

• Resolve resonances by multi-dimensional
  experiments

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The 2D NMR Pulse Sequence

1D 1D 2D
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2D NMR Coupling is the Key
2D detect signals twice (before/after coupling)
90º pulse
t1
t2
Transfers between coupled spins
Same as 1D experiment
t1
t2
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The 2D NMR Spectrum
Pulse Sequence
Spectrum
Before mixing
Coupled spins
After mixing
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The Power of 2D NMRResolving Overlapping Signals
1D
2 signals overlapped
2D
2 cross peaks resolved
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Acronyms For Basic ExperimentsDiffer Only By The
Nature Of Mixing
Homonuclear
Heteronuclear
Scalar Coupling
COSY
HSQC
TOCSY
Hetero-TOCSY
HMQC
Multiple Quantum
Dipolar Coupling
NOESY
NOESY-HSQC
NOESY-HMQC
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Higher Dimensional NMRBuilt on the 2D Principle
3D- detect signals 3 times
90º pulse
(t3)
Same as 1D experiment
3D NMR Pulse Sequence

• Experiments are composites ? acronyms are
  composites