Biomedical Engineering Reference
In-Depth Information
development of NMR pulse schemes that allow selective spin-state excitation
14
or transfer,
15
several TROSY experiments have been developed for different
spins systems. To date, TROSY experiments have been described for optimised
observation of
15
N-
1
H amide groups,
11,16
aromatic
13
C-
1
H sites
17-19
or
13
C
1
H
2
methylene groups.
20
For
13
C
1
H
3
methyl groups, the simple 2D HMQC
experiment has been shown to preserve the slowly relaxing methyl group
coherences independently from the more rapidly relaxing component of the
NMR spectra of a [b-
13
CH
3
]alanine-labelled 468 kDa homododecamer
showing the improvement in quality obtained on perdeuteration. Three-
dimensional structure of TET2 (2wzn) showing the location of (a) all
protons and (b) only alanine Hb. Two-dimensional (
1
H,
13
C) methyl
HMQC spectra of (c) [U-
13
C]-labelled and (d) [U-
2
H, b-
13
CH
3
]alanine-
labelled TET2. NMR spectra were recorded of 0.5 mM samples
(monomer concentration) using an 800 MHz spectrometer equipped
with a cryogenically cooled probehead in 60 min for the [U-
2
H,
b-
13
CH
3
]alanine-labelled sample [spectrum (d)] and overnight for
[b-
13
CH
3
]alanine-labelled sample [spectrum (c)]. The relevant assign-
ments of TET2 are shown in (d).
27
Figure 1.2
