Friday, October 24, 2014

DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature

Jakdetchai, O., et al., DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature. J Am Chem Soc, 2014.

DNP-enhanced solid-state NMR has been shown to hold great potential for functional studies of membrane proteins at low temperatures due to its great sensitivity improvement. There are however numerous applications, for which experiments at ambient temperature are desirable and which would also benefit from DNP signal enhancement. Here, we demonstrate as a proof of concept that a significant signal increase for lipid bilayers under room temperature conditions can be achieved by utilizing the Overhauser effect. Experiments were carried out on aligned bilayers at 400 MHz/263 GHz using a stripline structure combined with a Fabry-Perot microwave resonator. A signal enhancement of protons of up to -10 was observed. Our results demonstrate that Overhauser DNP at high field pro-vides efficient polarization transfer within insoluble samples, which is driven by fast local molecular fluc-tuations. Furthermore, our experimental setup offers an attractive option for DNP-enhanced solid-state NMR on ordered membranes and provides a general perspective towards DNP at ambient temperatures.