Blocking oestradiol synthesis pathways with potent and selective coumarin derivatives
A comprehensive set of 3-phenylcoumarin analogues with polar substituents was synthesised for blocking oestradiol synthesis by 17-b-hydroxysteroid dehydrogenase 1 (HSD1) in the latter part of the sulphatase pathway. Five analogues produced 62% HSD1 inhibition at 5 mM and, furthermore, three of them produced 68% inhibition at 1 mM. A docking-based structure-activity relationship analysis was done to determine the molecular basis of the inhibition and the cross-reactivity of the analogues was tested against oestrogen receptor, aromatase, cytochrome P450 1A2, and monoamine oxidases. Most of the analogues are only modestly active with 17-b-hydroxysteroid dehydrogenase 2 – a requirement for lowe…
Getting Docking into Shape Using Negative Image-Based Rescoring
The failure of default scoring functions to ensure virtual screening enrichment is a persistent problem for the molecular docking algorithms used in the structure-based drug discovery. To remedy this problem, elaborate rescoring and post-processing schemes have been developed with a varying degree of success, specificity, and cost. The negative imagebased rescoring (R-NiB) has been shown to improve the flexible docking performance markedly with a variety of drug targets.The yield improvement is achieved by comparing the alternative docking poses against the negative image of the target protein’s ligand-binding cavity. In other words, the shape and electrostatics of the binding pocket is dir…
Improving Docking Performance Using Negative Image-Based Rescoring
Despite the large computational costs of molecular docking, the default scoring functions are often unable to recognize the active hits from the inactive molecules in large-scale virtual screening experiments. Thus, even though a correct binding pose might be sampled during the docking, the active compound or its biologically relevant pose is not necessarily given high enough score to arouse the attention. Various rescoring and post-processing approaches have emerged for improving the docking performance. Here, it is shown that the very early enrichment (number of actives scored higher than 1% of the highest ranked decoys) can be improved on average 2.5-fold or even 8.7-fold by comparing th…
Rocker: Open source, easy-to-use tool for AUC and enrichment calculations and ROC visualization
Receiver operating characteristics (ROC) curve with the calculation of area under curve (AUC) is a useful tool to evaluate the performance of biomedical and chemoinformatics data. For example, in virtual drug screening ROC curves are very often used to visualize the efficiency of the used application to separate active ligands from inactive molecules. Unfortunately, most of the available tools for ROC analysis are implemented into commercially available software packages, or are plugins in statistical software, which are not always the easiest to use. Here, we present Rocker, a simple ROC curve visualization tool that can be used for the generation of publication quality images. Rocker also…
Discovery of Retinoic Acid-Related Orphan Receptor γt Inverse Agonists via Docking and Negative Image-Based Screening
Retinoic acid-related orphan receptor γt (RORγt) has a vital role in the differentiation of T-helper 17 (TH17) cells. Potent and specific RORγt inverse agonists are sought for treating TH17-related diseases such as psoriasis, rheumatoid arthritis, and type 1 diabetes. Here, the aim was to discover novel RORγt ligands using both standard molecular docking and negative image-based screening. Interestingly, both of these in silico techniques put forward mostly the same compounds for experimental testing. In total, 11 of the 34 molecules purchased for testing were verified as RORγt inverse agonists, thus making the effective hit rate 32%. The pIC50 values for the compounds varied from 4.9 (11 μ…
LIISA-ionilähteen vetyplasman VUV-spektrin ja H ̄ -ionisuihkun intensiteetin korrelaatio
Tässä työssä tutkitaan negatiivisen vetyionilähteen plasman tuottaman ultraviolettisäteilyn ja ionilähteen tuottaman negatiivisen vetyionisuihkun intensiteetin välistä korrelaatiota. Työssä löydettiin korrelaatio VUV-spektrin tiettyjen aallonpituusalueiden intensiteettien välisen suhteen ja Faraday-kupilla mitatun suihkuintensiteetin välillä. Korrelaatio ei kuitenkaan ole yksiselitteinen ja pätee ainoastaan rajoitetussa painealueessa. Vetyplasman molekylaarisen emission Lyman-vyön spektrin ja suihkun korrelaation tarkastelusta huomattiin, että elektronisen perustilan vibronisten viritystilojen 10 ja 11 tuoton suhde korkeampien viritystilojen tuottoon on olennainen negatiivisten vetyionien t…
Improving Docking Performance Using Negative Image-Based Rescoring
Despite the large computational costs of molecular docking, the default scoring functions are often unable to recognize the active hits from the inactive molecules in large-scale virtual screening experiments. Thus, even though a correct binding pose might be sampled during the docking, the active compound or its biologically relevant pose is not necessarily given high enough score to arouse the attention. Various rescoring and post-processing approaches have emerged for improving the docking performance. Here, it is shown that the very early enrichment (number of actives scored higher than 1% of the highest ranked decoys) can be improved on average 2.5-fold or even 8.7-fold by comparing th…