MyriaScreen II
Effective April 2024, Sigma-Aldrich/TimTec have discontinued MyriaScreen screening library, however 10.000 compounds from original library can be purchased in dry form or as a custom subset, pricing and availability are subject to change.
Ianire Martin, Jarl Underhaug, et.al. Screening and Evaluation of Small Organic Molecules as ClpB Inhibitors and Potential Antimicrobials. J. Med. Chem., 2013, 56 (18), pp 7177–7189. DOI: 10.1021/jm400499k
Abstract
Inhibition of ClpB, the bacterial representative of the heat-shock protein 100 family that is associated with virulence of several pathogens, could be an effective strategy to develop new antimicrobial agents. Using a high-throughput screening method, we have identified several compounds that bind to different conformations of ClpB and analyzed their effect on the ATPase and chaperone activities of the protein. Two of them inhibit these functional properties as well as the growth of Gram negative bacteria (E. coli), displaying antimicrobial activity under thermal or oxidative stress conditions. This activity is abolished upon deletion of ClpB, indicating that the action of these compounds is related to the stress cellular response in which ClpB is involved. Moreover, their moderate toxicity in human cell lines suggests that they might provide promising leads against bacterial growth.
Ana Jorge-Finnigan, Sandra Brasil, et.al. Pharmacological chaperones as a potential therapeutic option in methylmalonic aciduria cblB type. Hum Mol Genet. 2013 Sep 15;22(18):3680-9. doi: 10.1093/hmg/ddt217
Abstract
Methylmalonic aciduria (MMA) cblB type is caused by mutations in the MMAB gene. This encodes the enzyme ATP:cob(I)alamin adenosyltransferase (ATR), which converts reduced cob(I)alamin to an active adenosylcobalamin cofactor. We recently reported the presence of destabilizing pathogenic mutations that retain some residual ATR activity. The aim of the present study was to seek pharmacological chaperones as a tailored therapy for stabilizing the ATR protein. High-throughput ligand screening of over 2000 compounds was performed; six were found to enhance the thermal stability of purified recombinant ATR. Further studies using a well-established bacterial system in which the recombinant ATR protein was expressed in the presence of these six compounds, showed them all to increase the stability of the wild-type ATR and the p.Ile96Thr mutant proteins. Compound V (N-{[(4-chlorophenyl)carbamothioyl]amino}-2-phenylacetamide) significantly increased this stability and did not act as an inhibitor of the purified protein. Importantly, compound V increased the activity of ATR in patient-derived fibroblasts harboring the destabilizing p.Ile96Thr mutation in a hemizygous state to within control range. When cobalamin was coadministrated with compound V, mutant ATR activity further improved. Oral administration of low doses of compound V to C57BL/6J mice for 12 days, led to increase in steady-state levels of ATR protein in liver and brain (disease-relevant organs). These results hold promise for the clinical use of pharmacological chaperones in MMA cblB type patients harboring chaperone-responsive mutations.
Barrow EW, Clinkenbeard PA, et.al. High-throughput screening of a diversity collection using biodefense category A and B priority pathogens. J Biomol Screen. 2012 Aug;17(7):946-56. doi: 10.1177/1087057112448216
Colleen Knoth, Melinda S. Salus, et. al. The Synthetic Elicitor 3,5-Dichloroanthranilic Acid Induces NPR1-Dependent and NPR1-Independent Mechanisms of Disease Resistance in Arabidopsis. Plant Physiology May 2009 vol. 150 no. 1 333-347 doi: http://dx.doi.org/10.1104/pp.108.133678
Abstract
Immune responses of Arabidopsis (Arabidopsis thaliana) are at least partially mediated by coordinated transcriptional up-regulation of plant defense genes, such as the Late/sustained Up-regulation in Response to Hyaloperonospora parasitica (LURP) cluster. We found a defined region in the promoter of the LURP member CaBP22 to be important for this response. Using a CaBP22 promoter-reporter fusion, we have established a robust and specific high-throughput screening system for synthetic defense elicitors that can be used to trigger defined subsets of plant immune responses. Screening a collection of 42,000 diversity-oriented molecules, we identified 114 candidate LURP inducers. One representative, 3,5-dichloroanthranilic acid (DCA), efficiently induced defense reactions to the phytopathogens H. parasitica and Pseudomonas syringae. In contrast to known salicylic acid analogs, such as 2,6-dichloroisonicotinic acid (INA), which exhibit a long-lasting defense-inducing activity and are fully dependent on the transcriptional cofactor NPR1 (for Nonexpresser of Pathogenesis-Related genes1), DCA acts transiently and is only partially dependent on NPR1. Microarray analyses revealed a cluster of 142 DCA- and INA-responsive genes that show a pattern of differential expression coinciding with the kinetics of DCA-mediated disease resistance. These ACID genes (for Associated with Chemically Induced Defense) constitute a core gene set associated with chemically induced disease resistance, many of which appear to encode components of the natural immune system of Arabidopsis.
Morrow, John K., "Targeting TRAF6 for Cancer Therapeutical Development" (2012).UT GSBS Dissertations and Theses (OpenAccess). Paper 293. Retreaved From: Link
Abstract
Tumor necrosis factor (TNF)-Receptor Associated Factors (TRAFs) are a family of signal transducer proteins. TRAF6 is a unique member of this family in that it is involved in not only the TNF superfamily, but the toll-like receptor (TLR)/IL-1R (TIR) superfamily. The formation of the complex consisting of Receptor Activator of Nuclear Factor κ B (RANK), with its ligand (RANKL) results in the recruitment of TRAF6, which activates NF-κB, JNK and MAP kinase pathways. TRAF6 is critical in signaling with leading to release of various growth factors in bone, and promotes osteoclastogenesis. TRAF6 has also been implicated as an oncogene in lung cancer and as a target in multiple myeloma. In the hopes of developing small molecule inhibitors of the TRAF6-RANK interaction, multiple steps were carried out. Computational prediction of hot spot residues on the protein-protein interaction of TRAF6 and RANK were examined. Three methods were used: Robetta, KFC2, and HotPoint, each of which uses a different methodology to determine if a residue is a hot spot. These hot spot predictions were considered the basis for resolving the binding site for in silico high-throughput screening using GOLD and the MyriaScreen database of drug/lead-like compounds. Computationally intensive molecular dynamics simulations highlighted the binding mechanism and TRAF6 structural changes upon hit binding. Compounds identified as hits were verified using a GST-pull down assay, comparing inhibition to a RANK decoy peptide. Since many drugs fail due to lack of efficacy and toxicity, predictive models for the evaluation of the LD50 and bioavailability of our TRAF6 hits, and these models can be used towards other drugs and small molecule therapeutics as well. Datasets of compounds and their corresponding bioavailability and LD50 values were curated based, and QSAR models were built using molecular descriptors of these compounds using the k-nearest neighbor (k-NN) method, and quality of these models were cross-validated.
Jamin, Augusta V. (2011). Chemical and Molecular Genetics Approach to Study ROP1 Signaling Pathway in Pollen Tubes. UC Riverside: Genetics, Genomics and Bioinformatics. Retrieved from: Link
Abstract
Polarized growth in pollen tube requires complex signaling events including ROP1 GTPase pathway and calcium signaling. The role of tip calcium in negative feedback regulation of ROP1 remains a question and potentially involves ROP1 negative regulator, REN1GAP, whose activity seems to be regulated by calcium. Calcium-dependent protein kinases (CDPKs/CPKs) are calcium sensors with known function in regulating pollen tube tip growth. As such, we hypothesized that CPK substrate(s) in pollen tube may be component of tip growth regulator such as REN1. Here we report that REN1 is phosphorylated by pollen-expressed CPK16 with a relative EC50 value of ~4.6 µM. MS/MS analysis revealed calcium-dependent phosphorylation sites within REN1 which include Ser70 and Ser267. Functional analyses suggested that REN1 phosphorylation at Ser267 is required for its activity while at Ser70,71 affected its localization and subsequently activity. Mutation analysis of CPK16 loss-of-function, cpk16-3, revealed enhanced pollen tube growth and germination when grown in low calcium media. Treatment of cpk16-3 tubes with either brefeldin A or latrunculin B induced tip swelling phenotype similar to the same effects produced by chemical treatments of partially complemented ren1-1 Lat52::GFP-REN1, Overall, these results suggest a link between calcium and a major signaling pathway, ROP1, via calcium-dependent protein kinase and its substrate REN1.To dissect the causal and phasal relationships between oscillations of growth, active ROP1, F-actin dynamics, and tip-focused calcium, a chemical genetics approach was utilized with the goal to identify small molecules that would specifically activate ROP1. To this end, 20000 chemicals were screened in a cell-based yeast two hybrid assay to target inhibitors of active ROP and GAP. One compound, #7, inhibited ROP-GAP interaction as confirmed by in vitro assays as well as slightly enhanced pollen tube tip width. Treatment of ROP1 OX severely enhanced tip swelling suggesting that it primarily targets ROP1. Docking analyses of compound 7 to the protein interaction interface of RhoA and p190RhoGAP revealed possible binding sites within the GTP-binding pockets of Rho-GAP interface in potentially disrupting protein-protein interaction. This study leads to a potential activator of ROP1 which may be useful for future ROP1 studies.