A simple vapor-diffusion method enables protein crystallization inside the HARE serial crystallography chip

A Practical Guide to 3D Printing for Chemistry and Biology Laboratories

Three-dimensional (3D) printing promises a revolution in laboratory creativity by enabling rapid prototyping, broader availability of scientific apparatuses, and transformative scientific workflows. We believe all chemistry and biology laboratories should equip themselves with one or more 3D printers and a critical mass of scientists trained to operate them. This overview surveys the techniques, intricacies, and pitfalls associated with 3D printing of functional parts, including measurements, computer-aided design, slicing, limitations of 3D printing, troubleshooting, tips for tricky filaments, and 3D printer maintenance. A flow cells are essential tools in chemistry and biology laboratories, we discuss techniques relevant to the construction of watertight 3D-printed parts. Finally, we articulate a set of principles required for reporting 3D-printed innovations to improve the field's reproducibility and encourage iterative improvements by other scientists. Ideally, authors, peer reviewers, and editors will adopt these principles. We hope these protocols inspire a new generation of publications applying 3D printing in chemistry and biology-especially highly reproducible inventions with the requisite detail and associated documentation. Such reports will facilitate broad adoption and creative iteration of the most innovative designs, thus accelerating discovery in chemistry and biology. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC.

A streamlined approach to structure elucidation using in cellulo crystallized recombinant proteins, InCellCryst

With the advent of serial X-ray crystallography on microfocus beamlines at free-electron laser and synchrotron facilities, the demand for protein microcrystals has significantly risen in recent years. However, by in vitro crystallization extensive efforts are usually required to purify proteins and produce sufficiently homogeneous microcrystals. Here, we present InCellCryst, an advanced pipeline for producing homogeneous microcrystals directly within living insect cells. Our baculovirus-based cloning system enables the production of crystals from completely native proteins as well as the screening of different cellular compartments to maximize chances for protein crystallization. By optimizing cloning procedures, recombinant virus production, crystallization and crystal detection, X-ray diffraction data can be collected 24 days after the start of target gene cloning. Furthermore, improved strategies for serial synchrotron diffraction data collection directly from crystals within living cells abolish the need to purify the recombinant protein or the associated microcrystals.

A simple goniometer-compatible flow cell for serial synchrotron X-ray crystallography

Serial femtosecond crystallography was initially developed for room-temperature X-ray diffraction studies of macromolecules at X-ray free electron lasers. When combined with tools that initiate biological reactions within microcrystals, time-resolved serial crystallography allows the study of structural changes that occur during an enzyme catalytic reaction. Serial synchrotron X-ray crystallography (SSX), which extends serial crystallography methods to synchrotron radiation sources, is expanding the scientific community using serial diffraction methods. This report presents a simple flow cell that can be used to deliver microcrystals across an X-ray beam during SSX studies. This device consists of an X-ray transparent glass capillary mounted on a goniometer-compatible 3D-printed support and is connected to a syringe pump via light-weight tubing. This flow cell is easily mounted and aligned, and it is disposable so can be rapidly replaced when blocked. This system was demonstrated by collecting SSX data at MAX IV Laboratory from microcrystals of the integral membrane protein cytochrome c oxidase from Thermus thermophilus, from which an X-ray structure was determined to 2.12 Å resolution. This simple SSX platform may help to lower entry barriers for non-expert users of SSX.

Sample Preparation for Time-Resolved Serial Crystallography: Practical Considerations

Time-resolved serial crystallography is an emerging method to elucidate the structure-function relationship of biomolecular systems at up to atomic resolution. However, to make this demanding method a success, a number of experimental requirements have to be met. In this chapter, we summarize general guidelines and protocols towards performing time-resolved crystallography experiments, with a particular emphasis on sample requirements and preparation but also a brief excursion into reaction initiation.

A 3D Printer in the Lab: Not Only a Toy

Although 3D printers are becoming more common in households, they are still under-represented in many laboratories worldwide and regarded as toys rather than as laboratory equipment. This short review wants to change this conservative point of view. This mini-review focuses on fused deposition modeling printers and what happens after acquiring your first 3D printer. In short, these printers melt plastic filament and deposit it layer by layer to create the final object. They are getting cheaper and easier to use, and nowadays it is not difficult to find good 3D printers for less than €500. At such a price, a 3D printer is one, if not the most, versatile piece of equipment you can have in a laboratory.

Deamidation of the human eye lens protein γS-crystallin accelerates oxidative aging

Cataract, a clouding of the eye lens from protein precipitation, affects millions of people every year. The lens proteins, the crystallins, show extensive post-translational modifications (PTMs) in cataractous lenses. The most common PTMs, deamidation and oxidation, promote crystallin aggregation; however, it is not clear precisely how these PTMs contribute to crystallin insolubilization. Here, we report six crystal structures of the lens protein γS-crystallin (γS): one of the wild-type and five of deamidated γS variants, from three to nine deamidation sites, after sample aging. The deamidation mutations do not change the overall fold of γS; however, increasing deamidation leads to accelerated disulfide-bond formation. Addition of deamidated sites progressively destabilized protein structure, and the deamidated variants display an increased propensity for aggregation. These results suggest that the deamidated variants are useful as models for accelerated aging; the structural changes observed provide support for redox activity of γS-crystallin in the lens.

The dual function of impurity in protein crystallization

Protein crystallization could be promoted with a low concentration of impurities and inhibited with a high concentration of impurities, and this inhibition can be weakened by an audible sound.

Best practices for time-resolved serial synchrotron crystallography

With recent developments in X-ray sources, instrumentation and data-analysis tools, time-resolved crystallographic experiments, which were originally the preserve of a few expert groups, are becoming simpler and can be carried out at more radiation sources, and are thus increasingly accessible to a growing user base. However, these experiments are just that: discrete experiments, not just `data collections'. As such, careful planning and consideration of potential pitfalls is required to enable a successful experiment. Here, some of the key factors that should be considered during the planning and execution of a time-resolved structural study are outlined, with a particular focus on synchrotron-based experiments.