Q-Band FT-EPR Spektrometer

因此，我们申请一台专用Q波段脉冲光谱仪，配备：(I)150 W行波管放大器，提供商业上最高的微波功率；(Ii)最新开发的任意波形发生器(AWG)技术，提供所有可以数学描述的波形特征--这是脉冲EPR实验的真正突破。这台光谱仪将主要用于鹿自旋标记的膜蛋白。在基于氮氧化物的鹿的情况下，高功率Q波段的设置与可用的自制谐振器一起将允许：(I)在相同数量的样品上，相对于传统的X波段鹿，信噪比提高约20%；(Ii)在12-24小时的测量时间内确定自旋浓度降至20微摩尔的样品的自旋间距离；(Iii)在没有取向选择和质子调制伪像的生理环境中对复杂生物系统进行生物物理研究。如果不使用传统的X波段或低功率Q波段的鹿，所有这些成就都是不可能的。对于氮氧化物以外的探头，例如金属中心，新的AWG设置将允许使用专用脉冲序列来提高鹿实验的灵敏度。因此，研究细胞环境中的正交标记蛋白质和蛋白质网络将成为可能。

Hereby we apply for a dedicated Q-band pulsed spectrometer equipped with: (i) a 150 W TWT amplifier, providing the highest commercially available microwave power; (ii) the newly developed technology of Arbitrary Waveform Generators (AWG), providing all waveform features that can be described mathematically - a true breakthrough for pulsed-EPR experiments. This spectrometer will be mainly used for DEER on spin-labeled membrane proteins. In the case of nitroxide-based DEER, the high-power Q-band setup together with an available home-made resonator will allow (i) an increase of about 20 in signal-to-noise with respect to conventional X-band DEER on the same amount of sample; (ii) determination of interspin distances on samples with spin concentrations down to 20 micromolar in a 12-24 h measurement time; (iii) biophysical studies on complex biosystems in physiological environments without orientation selection and proton modulation artifacts. All these achievements are otherwise impossible using conventional X-band or low-power Q-band DEER. For probes other than nitroxides, e.g. metal centers, the new AWG setup will allow the use of dedicated pulsesequences to improve sensitivity in DEER experiments. Therefore, the study of orthogonally-labeled proteins and protein networks in cellular environments will become possible.