Large Temperature-Jump and Nanosecond Hyperquenching for Time-Resolved Structural Studies

Abstract

The quest for atomic structures of microsecond reaction intermediates is at the frontline of modern biochemistry. Currently, there is a clear lack of experimental methods for preparing necessary time-resolved samples. Here, we report the development of a single-turnover technique for nanosecond initiation and suspension of biomolecular reactions with kinetic resolution in the microsecond time domain. Reactions can be started by large temperature-jump or direct mixing and arrested by hyperquenching in liquid cryogen at a target temperature of 77 K. Diverse morphology of nanoscale glassy bodies feature among others thin field-of-view plane sheets that can be used for structure analyses of freeze-trapped macromolecules by transmission electron cryomicroscopy. We also report the ultra-high vacuum sublimation at 77 K – a novel method for concentrating reaction intermediates for structural studies by low-temperature techniques.