. Author manuscript; available in PMC: 2017 Mar 1.

Published in final edited form as: J Biomol NMR. 2016 Feb 12;64(3):223–237. doi: 10.1007/s10858-016-0023-3

Table 3.

Summary of the effects of sample preparation protocols on DNP sensitivity enhancement of membrane peptides. The optimal conditions are in italic.

Parameters	Relative sensitivity enhancement
AMUPol vs TOTAPOL	AMUPol yields 4-fold higher ε_C_,_CP.
Titration vs centrifugation	Direct titration yields 1.5–2.5 fold higher ε_C_,_CP due to better mixing of the radical with the membrane.
Glycerol vs DMSO	Glycerol yields 1.5-fold higher ε _C_,_CP.
Deuterated lipids vs protonated lipids	Perdeuterated lipids yield 1.5–2.0 times higher peptide ε_C_,_CP. However, perdeuterated lipids cause lower peptide ¹³C CP signals in the MW-off spectra, thus the sensitivities of the MW-on spectra are similar between protonated and deuterated membranes.
DMPC vs DLPE	DLPE gives sharper signals for disordered peptide residues.