Nuclear magnetic resonance, deuterium organisms in

Deuterium Orgemisms in Esr. The availcibility of fully deuterated algae has permitted some significant biological problems to be attacked in new and effective ways. Deuterium had been used as a tool to aid in the simplification and interpretation of electron spin resonance (esr) and nuclear magnetic resonance (nmr) spectra of relatively simple organic molecules for many 

ACS Symposium Series American Chemical Society Washington, DC, 1975. 

Deuterated Proteins in Nmr. Deuterated proteins can also serve as the basis for the simplification of the highly complex Hmr spectra of these molecules. Three basic experiments to this end have been described in the literature (1 ). (1) An autotrophic organism 

The protein resonance lines obtained in an Hmr experiment are generally quite broad. The large protein molecules tumble slowly in solution, and many dipole-dipole magnetic interactions and chemical shift anisotropies are not averaged out. In general, amide proton resonance peaks in molecules with molecular weights of 10-20,000 daltons have linewidths of the order of 30-35 Hz. However, in a deuterated protein, the dipole-dipole interaction is much decreased and most amide protons have linewidths in the range of 15-18 Hz. These amide protons appear 6 to 11 ppm down-field from tetramethylsilane, and the proton resonances 

H has a spin of 1/2 and a magnetic moment of 2.793 nuclear magnetons. 2h has a spin of 1 and a magnetic moment of 0.857 nuclear magnetons. Thus, when a deuterium atom is substituted for a protium atom, coupling constants are reduced by a factor of 6.5 and the frequency at which energy level transitions take place is also reduced by a factor of 6.5. 

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