Deuterated Proteins.
Advantages vs Drawbacks
Advantages of using deuterated proteins:
-
Increase of the transverse T2 relaxation times of the 13C,
15N and remaining 1H nuclei which occurs upon substitution
of 1H for 2H since the gyromagnetic ratio of 2H
is 6.5 times smaller than that of 1H. A straightforward approach is based
in the substitution of CH spin systems by CD. For instance, the average
T2 of 13CA magnetization of a 37kDa protein/DNA complex
was 16 ms for the protonated sample and 130 ms for the deuterated one (
94JACS11655
).
-
The slower relaxation of 13C makes it possible to extend the
length of the evolution period as to obtain higher resolution in the indirect
dimensionsby using Constant-time 13C periods.
-
Mimimization/Suppression of undesired spin difussion effects.
-
Elimination of passive couplings.
-
Decrease of NH and 13C linewidths due to the reduction
in proton-proton spin coupling, leading to a further increase in sensitivity
and resolution.
Drawbacks of using deuterated proteins:
-
Loss of 1H nuclei, which provide useful structural information
through NOE experiments. A limited number of interproton distance restraints
are available for structure determination and, therefore, other alternative
NMR restraints might be necessary.
-
One-bond 2H isotope effects can be taken in account.
-
With a random partial deuteration, the attached nuclei show a range of
chemical shifts.
-
New pulse sequences involving 2H decoupling are required.