The HARE chip for efficient time-resolved serial synchrotron crystallography.

Pedram Mehrabi,Sascha W Epp,Arwen R Pearson,Robin L Owen,Jelena Ninkovic,Silvia Krivokuca,Jan-Philipp Leimkohl,Hendrik Schikora,Friedjof Tellkamp,Henrike M Müller-Werkmeister,Ladislav Andriček,Darren Sherrell,R J Dwayne Miller,Eike C Schulz

doi:10.1107/s1600577520000685

Abstract

Serial synchrotron crystallography (SSX) is an emerging technique for static and time-resolved protein structure determination. Using specifically patterned silicon chips for sample delivery, the `hit-and-return' (HARE) protocol allows for efficient time-resolved data collection. The specific pattern of the crystal wells in the HARE chip provides direct access to many discrete time points. HARE chips allow for optical excitation as well as on-chip mixing for reaction initiation, making a large number of protein systems amenable to time-resolved studies. Loading of protein microcrystals onto the HARE chip is streamlined by a novel vacuum loading platform that allows fine-tuning of suction strength while maintaining a humid environment to prevent crystal dehydration. To enable the widespread use of time-resolved serial synchrotron crystallography (TR-SSX), detailed technical descriptions of a set of accessories that facilitate TR-SSX workflows are provided.

Highlights

Time-resolved crystallography is one of the few techniques that can provide simultaneous insight into structure and dynamics with near-atomic resolution (Moffat, 1989, 1998; Pai, 1992)
Using patterned silicon chips for sample delivery, the ‘hit-and-return’ (HARE) protocol allows for efficient time-resolved data collection
HARE chip design allows for smaller crystal sizes and higher crystalwell densities

Summary

Introduction

Time-resolved crystallography is one of the few techniques that can provide simultaneous insight into structure and dynamics with near-atomic resolution (Moffat, 1989, 1998; Pai, 1992) This method has experienced a renaissance since the advent of high-brilliance X-ray free-electron laser (XFEL) sources. Liquid jets brought new challenges: collecting thousands of still diffraction patterns mandates high-velocity crystal exchange, which initially resulted in large sample consumption and waste. This made studying scarce, expensive or difficult to crystallize systems unfeasible and led to the development of high-

Methods

Results

Conclusion