X-ray Crystallography

In this case study, Ariadna Juarez-Martinez describes how optimising the crystal system for a target protein was ultimately the key to delivering a successful fragment screen for one of our clients. 152 high-confidence fragments were identified that bound across 24 binding hotspots on the [...]

In this Case Study Helen Gingell and Thirumalai Ulaganathan give an introduction to Fragment based drug discovery (FBDD) with a focus on using X-ray crystallography to perform FBDD. This is exemplified with a description of a project in which Sygnature Discovery ran a fragment [...]

The Name's Bond... Covalent Bond. Covalent compounds have historically accounted for a significant number of successful drugs, but interest waned due to concerns about poor selectivity that is often identified in early assay screening. One of the key hurdles in a covalent drug campaign [...]

AlphaFold AlphaFold is a deep learning system, developed by DeepMind that predicts a protein’s 3D structure from its amino acid sequence. After publication in Nature in 2021, AlphaFold was subsequently used across the entire human proteome. This has since expanded to 48 organisms date which are all [...]

In a previous case study, we have described the benefits of using the HEK293 suspension cell system in combination with the mannosidase inhibitor, kifunensine, and endoglycosidase H (EndoH) treatment to successfully crystallise complex proteins by removing bulky, N-linked oligosaccharides. Increasingly, we are relying on [...]

The final purification step prior to protein crystallisation is frequently size-exclusion chromatography in the desired buffer. This enables the purification of a single oligomeric species making successful crystallisation much more likely. A frequent challenge whilst purifying proteins however is their tendency to aggregate. [...]

A client was looking to solve the crystal structure of a secreted protein which contained a number of disulphide bonds and potential N-linked glycosylation sites, which leads to the attachment of complex sugar molecules. There was already literature available describing the expression of [...]

Our client required >2 mg of a novel, secreted protein for X-ray structure determination studies. The protein was thought to be N-glycosylated. Our Solution Our solution was to evaluate three C-terminally deleted constructs for secreted expression in HEK cells, based on structural alignments [...]