XFEL Microcrystallography of Self-Assembling Silver -Alkanethiolates.

New synthetic hybrid materials and their increasing complexity have placed growing demands on crystal growth for single-crystal X-ray diffraction analysis. Unfortunately, not all chemical systems are conducive to the isolation of single crystals for traditional characterization. Here, small-molecule serial femtosecond crystallography (smSFX) at atomic resolution (0.

Co-flow injection for serial crystallography at X-ray free-electron lasers.

Serial femtosecond crystallography (SFX) is a powerful technique that exploits X-ray free-electron lasers to determine the structure of macro-molecules at room temperature. Despite the impressive exposition of structural details with this novel crystallographic approach, the methods currently available to introduce crystals into the path of the X-ray beam sometimes exhibit serious drawbacks. Samples requiring liquid injection of crystal slurries consume large quantities of crystals (at times up to a gram of protein per data set), may not be compatible with vacuum configurations on beamlines or provide a high background due to additional sheathing liquids present during the injection.

Triangular Self-Assembling Coiled-Coil Protein Origami.

Coiled-coil protein origami (CCPO) polyhedra are designed self-assembling nanostructures constructed from coiled coil (CC)-forming modules connected into a single chain. For testing new CCPO building modules, simpler polyhedra could be used that should maintain most features relevant to larger scaffolds. We show the design and characterization of nanoscale single-chain triangles, composed of six concatenated parallel CC dimer-forming segments connected by flexible linker peptides.

E3 ubiquitin-protein ligase TRIM21-mediated lysine capture by UBE2E1 reveals substrate-targeting mode of a ubiquitin-conjugating E2.

The E3 ubiquitin-protein ligase TRIM21, of the RING-containing tripartite motif (TRIM) protein family, is a major autoantigen in autoimmune diseases and a modulator of innate immune signaling. Together with ubiquitin-conjugating enzyme E2 E1 (UBE2E1), TRIM21 acts both as an E3 ligase and as a substrate in autoubiquitination. We here report a 2.

Online Size-exclusion and Ion-exchange Chromatography on a SAXS Beamline.

Biological small angle X-ray scattering (BioSAXS) is a powerful technique in molecular and structural biology used to determine solution structure, particle size and shape, and surface-to-volume ratio of macromolecules. The technique is applicable to a very wide variety of solution conditions spanning a broad range of concentrations, pH values, ionic strengths, temperatures, additives, etc., but the sample is required to be monodisperse.

Noncovalent PEGylation via Lectin-Glycopolymer Interactions.

PEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g.

Structural and Functional Highlights of Vacuolar Soluble Protein 1 from Pathogen Trypanosoma brucei brucei.

Trypanosoma brucei (T. brucei) is responsible for the fatal human disease called African trypanosomiasis, or sleeping sickness. The causative parasite, Trypanosoma, encodes soluble versions of inorganic pyrophosphatases (PPase), also called vacuolar soluble proteins (VSPs), which are localized to its acidocalcisomes.

The pentameric nucleoplasmin fold is present in Drosophila FKBP39 and a large number of chromatin-related proteins.

Nucleoplasmin is a histone chaperone that consists of a pentameric N-terminal domain and an unstructured C-terminal tail. The pentameric core domain, a doughnut-like structure with a central pore, is only found in the nucleoplasmin family. Here, we report the first structure of a nucleoplasmin-like domain (NPL) from the unrelated Drosophila protein, FKBP39, and we present evidence that this protein associates with chromatin.

Small angle scatter imaging from wide beam diffraction patterns.

In this paper we report on the extension of the technique of mapping small angle x-ray scatter (SAXS) across a soft material specimen several millimetres square. In the conventional SAXS mapping technique a pencil beam of x-rays is raster scanned over the specimen with the scatter pattern recorded from each point in the raster. In our technique a wide, parallel beam is used, speeding up the data collection time considerably.