IDBR: Novel Electron-Nuclear Dual Resonance Instrument with Arbitrary Microwave Pulse Shaping to Advance the Structure and Dynamics Study of Biological Systems

X波段(10 GHz)任意脉冲整形模块将被集成到EPR光谱仪中，这将带来前所未有的和根本的重要进展，包括显著提高激发带宽，减少现有脉冲EPR仪器过长的死区时间，以及实验实现高光谱分辨率的傅里叶变换EPR。实施任意形状的微波脉冲还将使下一代定量和时间分辨的Overhauser DNP光谱能够探测具有位点特异性的蛋白质周围看不见的、松散结合的水合水的动力学。拟议的开发将利用最先进的集成电路元件来生成X波段波形，其幅度和相位可以以低于ns的分辨率动态指定。这种控制，再加上商用脉冲EPR光谱仪无与伦比的内置灵活性，将为仪器提供一种具有脉冲EPR和DNP所不具备的广泛质量和功能的仪器。最先进的EPR光谱仪还不能像25年来在现代核磁共振和核磁共振实验中通常所做的那样，提供对单个脉冲进行整形的能力。这项工作首次提出在最常用的X波段频率上为EPR实验实现任意形状的脉冲。这一进展有可能极大地提高当前脉冲EPR和DNP实验的精度、时间分辨率和光谱分辨率，使它们能够测量复杂和大型生物系统的结构参数、相互作用和动力学，这是其他方法无法获得的。

An arbitrary pulse shaping module at X-band (10 GHz) frequencies will be integrated into an EPR spectrometer that will lead to unprecedented and fundamentally important advances, including dramatic enhancement of excitation bandwidths, reduction of the prohibitively long dead times of current pulsed EPR instruments, and the experimental realization of Fourier Transform EPR with high spectral resolution. The implementation of arbitrarily shaped microwave pulses will also enable the next generation of quantitative and time-resolved Overhauser DNP spectroscopy to probe the dynamics of the otherwise invisible, loosely bound hydration water around proteins with site specificity. The proposed development will capitalize on state of the art integrated circuit components to generate X-band waveforms, whose amplitude and phase can be specified on the fly with sub-ns resolution. This control, coupled with the unsurpassed, built-in flexibility of a commercial pulsed EPR spectrometer will offer an instrument with a wide range of qualities and capabilities novel to pulsed EPR and DNP.State of the art EPR spectrometers do not yet offer the ability to shape individual pulses, as has routinely been done in modern NMR and MRI experiments for 25 years. This work proposes, for the first time, to implement arbitrarily shaped pulses for EPR experiments at the most commonly used X-band frequencies. This development has the potential to dramatically advance the accuracy, time resolution, and spectral resolution of current pulsed EPR and DNP experiments, allowing them to measure structural parameters, interactions, and dynamics of complex and large biological systems that are inaccessible to other methods.