Protein resonance assignment at MAS frequencies approaching 100 kHz: a quantitative comparison of J-coupling and dipolar-coupling-based transfer methods

摘要: We discuss the optimum experimental conditions to obtain assignment spectra for solid proteins at magic-angle spinning (MAS) frequencies around 100 kHz. present a systematic examination of MAS dependence amide proton T 2′ times and site-specific comparison 93 kHz versus 60 kHz frequency. A quantitative analysis transfer efficiencies building blocks, as they are used typical 3D experiments, was performed. To do this, we compared dipolar-coupling J-coupling based steps. The blocks were then combined into experiments sequential resonance assignment, where evaluated signal-to-noise ratio information content different in order identify best strategy. Based on this comparison, six selected optimally assign model protein ubiquitin, solely using acquired MAS. Within 3 days instrument time, required recorded from which backbone resonances have been assigned over 96 %.