RESUMO
Recently, we introduced the liquid application method for time-resolved analyses (LAMA). The time-consuming cleaning cycles required for the substrate solution exchange and storage of the sensitive droplet-dispenser nozzles present practical challenges. In this work, a dispenser cleaning system for the semi-automated cleaning of the piezo-actuator-driven picolitre-droplet dispensers required for LAMA is introduced to streamline typical workflows.
RESUMO
We introduce the spitrobot, a protein crystal plunger, enabling reaction quenching via cryo-trapping with a time-resolution in the millisecond range. Protein crystals are mounted on canonical micromeshes on an electropneumatic piston, where the crystals are kept in a humidity and temperature-controlled environment, then reactions are initiated via the liquid application method (LAMA) and plunging into liquid nitrogen is initiated after an electronically set delay time to cryo-trap intermediate states. High-magnification images are automatically recorded before and after droplet deposition, prior to plunging. The SPINE-standard sample holder is directly plunged into a storage puck, enabling compatibility with high-throughput infrastructure. Here we demonstrate binding of glucose and 2,3-butanediol in microcrystals of xylose isomerase, and of avibactam and ampicillin in microcrystals of the extended spectrum beta-lactamase CTX-M-14. We also trap reaction intermediates and conformational changes in macroscopic crystals of tryptophan synthase to demonstrate that the spitrobot enables insight into catalytic events.
