Virtual screening allows for the rapid screening of large libraries of compounds using computational approaches. In this way, it is possible for researchers to explore vast numbers of compounds in silico, the need for synthesize and test each compound experimentally.
This process therefore enhances the speed with which potential new drug candidates can be identified and significantly reduces the time and cost associated with experimental screening.
Our computer-aided drug design (CADD) experts use state-of-the-art systems and software to provide tailored solutions to your drug discovery project. Turn complex data into actionable insights that enhance the success and experience of your drug discovery program.
Virtual Screening
Structure-Based Virtual Screening (SBVS):
This type of virtual screening uses the known 3D structure of the target protein to identify potential drug leads. The 3D structure of the target protein can be obtained from X-ray crystallography or NMR spectroscopy, homology modelling, or by using AlphaFold predictions.
Ligand-Based Virtual Screening (LBVS):
In this approach, the focus is on the properties and characteristics of known active ligands or ligand sets rather than the target protein’s structure. Ligand-based methods use molecular descriptors, such as shape, electrostatics, and chemical fingerprints, to search a database of molecules and identify compounds similar to known active ligands.
What Do We Screen?
Commercial libraries
Commercial libraries often provide a diverse range of small molecules, covering a wide chemical space. These libraries are carefully curated to include compounds with diverse structural features, functional groups, and properties, and are usually suitable for rapid analoguing, allowing researchers to explore the chemical space around a hit compound, identifying structure-activity relationships and optimizing properties such as potency, selectivity, pharmacokinetics, or metabolic stability.
This helps to quickly leverage the knowledge gained from the initial hit and provides a rational framework for the discovery and development of new drug candidates.
Commercial providers often offer specialized libraries targeting specific classes of proteins, therapeutic areas, or chemical scaffolds. These targeted libraries can be valuable when working on specific drug targets or focusing on particular disease areas. They may contain compounds with known activity or structural motifs relevant to the target of interest.
Charnwood Discovery can facilitate the shipment of compounds in the required assay format for screening, enabling rapid progression from hit identification to hit optimization.
Custom libraries
While commercial libraries offer many advantages, they may not cover all chemical space or specific requirements of a particular research project. In some cases they need to be complemented with custom-made or in-house libraries to address specific needs or focus areas.
Custom-made chemical libraries refer to collections of compounds that are designed and synthesized specifically for a particular research project or drug discovery effort. These libraries are tailored to meet the specific requirements and goals of the project, and they are not commercially available off-the-shelf. They can range from a few dozen to thousands of compounds. The diversity of the library may be focused on specific functional groups of interest or targeted to explore a broader range of chemical space.
Custom-made libraries undergo quality control measures, including compound purity assessment, characterization, and confirmation of structural integrity. Analytical techniques such as Nuclear Magnetic Resonance (NMR), mass spectrometry, and High-Performance Liquid Chromatography (HPLC) are commonly employed to ensure the quality of the compounds.
Ultra Large Chemical Space
Ultra large chemical space refers to the vast and virtually infinite collection of all possible chemical compounds that can be synthesized or exist within the known chemical universe. It encompasses the vast number of potential small molecules that can be generated by combining different elements, functional groups, and structural motifs.
We can rapidly screen ultra large commercial libraries such as REAL Space, GalaXi, eXplore, Freedom Space and many more.
Do you need a crystal structure for virtual screening?
No, you do not necessarily need a crystal structure for virtual screening. Virtual screening methods can be performed even without a crystal structure of the target protein. There are two main approaches to virtual screening: ligand-based and structure-based.
While having a crystal structure of the target protein is advantageous for SVBS, it is not always a requirement. Homology models or other predicted structures can be used as substitutes when experimental structures are not available.
Did you know...
…that the earliest reported virtual screening campaign was in 1997 in the Journal of Medicinal Chemistry. 2500 molecules were screened against Trypanothione Reductase (TR). Out of 13 molecules tested, 9 displayed micromolar inhibition of TR activity.
