1,721,008 research outputs found
Biomolecular and biophysical approaches to interrogate p300: a platform for drug discovery.
No full textLysine acetylation is a protein post-translational modification which effect the relaxing of the chromatin structure, making chromosomal DNA more accessible. Among the different enzymes responsible for this transformation (KATs), p300 is one of the most studied: the dysregulation of its activity leads to many human diseases.
Nevertheless, a limited number of p300 modulators have been described so far: one of the main problem is the absence of a gold standard screening technique for this enzyme because of the intrinsic limitation of each method. We decided to develop a robust and widely usable combined screening platform to identify small molecule modulators of p300, using different biophysical and biomolecular techniques to interrogate the target and to validate the outputs.
The multiple platform was applied to two different libraries of small molecule compounds, derived from the molecular pruning of anacardic acid and garcinol, natural inhibitors of p300.
This combined approach allowed us to identify and deeply characterize the activity of new chemical probes, very useful for the study of p300-mediated lysine acetylation and its implications in physiological and/or pathological processes
DESIGN, SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVEL G9A INHIBITORS FROM A SCAFFOLD HOPPING APPROACH
No full textThe lysine methyltransferase G9a (also named euchromatin histone methyltransferase 2, EHMT2) is primarily responsible for the dimethylation of lysine 9 on histone H3 (H3K9). Several reports have
highlighted its link to a variety of cancers. In particular, it has been shown that G9a is crucial for the oncogenic role of the repressor element (RE)-1 silencing transcription factor (REST) in the pediatric brain tumor medulloblastoma. Only a few among the selective inhibitors of G9a reported to date are useful chemical probes for cell-based and animal studies. Starting from the inhibitor UNC0638,3 we applied a scaffold hopping approach to develop novel chemical entities endowed with high affinity towards the G9a. In particular, we replaced the quinazoline core, typical of most of the reported inhibitors, with 1,4-benzodiazepine nucleus, known to be a privileged structure. We chose the 3,4-dihydro-5H-benzo[e][1,4]diazepin-5-one scaffold, that can be obtained through an efficient and gram-scale continuous-flow protocol, previously optimized by our group.4 Moreover, this scaffold could be easily decorated to provide a number of highly functionalized potential ligands. To validate our approach, we designed and synthesized a small library of UNC0638 analogues. All the compounds were tested through a peptide-based AlphaLISA, measuring the levels of H3K9 dimethylation
Highly Enantioselective Organocatalytic α-Amination Reactions of Aryl Oxindoles: Developing Designer Multifunctional Alkaloid Catalysts
No full textAn enantioselective α-amination of aryl oxindoles catalyzed by a dimeric quinidine has been developed. The reaction is general, broad in substrate scope, and affords the desired products in good yields with good to excellent enantioselectivities. This study provides the first examples of a general organocatalytic method for the creation of nitrogen-containing, tetrasubstituted chiral centers at C3 of various aryl oxindoles. Furthermore, new catalysts and insights into structural elements of the catalysts that significantly influence enantioselectivities are disclosed
Highly efficient synthesis and chemical separation of 5-amino- and 7-amino-4-hydroxy-2-naphthoic acids
No full textA continuous-flow synthesis of 1,4-benzodiazepin-5-ones, privileged scaffolds for drug discovery
No full textAn efficient and gram-scale continuous-flow protocol for the synthesis of the privileged structure 3,4-dihydro-5H-benzo[e][1,4]diazepin-5-one is reported. If compared to the traditional metal mediated non-catalytic reduction procedure, this approach is high yielding and does not require purification steps and therefore could be conveniently used for the generation of compound libraries for drug discovery
CARM1 modulators affect epigenome of stem cells and change morphology of nucleoli
Full text linkCARM1 interacts with numerous transcription factors to mediate cellular processes, especially gene expression. This is important for the maintenance of ESC pluripotency or intervention to tumorigenesis. Here, we studied epigenomic effects of two potential CARM1 modulators: an activator (EML159) and an inhibitor (ellagic acid dihydrate, EA). We examined nuclear morphology in human and mouse embryonic stem cells (hESCs, mESCs), as well as in iPS cells. The CARM1 modulators did not function similarly in all cell types. EA decreased the levels of the pluripotency markers, OCT4 and NANOG, particularly in iPSCs, whereas the levels of these proteins increased after EML159 treatment. EML159 treatment of mouse ESCs led to decreased levels of OCT4 and NANOG, which was accompanied by an increased level of Endo-A. The same trend was observed for NANOG and Endo-A in hESCs affected by EML159. Interestingly, EA mainly changed epigenetic features of nucleoli because a high level of arginine asymmetric di-methylation in the nucleoli of hESCs was reduced after EA treatment. ChIP-PCR of ribosomal genes confirmed significantly reduced levels of H3R17me2a, in both the promoter region of ribosomal genes and rDNA encoding 28S rRNA, after EA addition. Moreover, EA treatment changed the nuclear pattern of AgNORs (silver-stained nucleolus organizer regions) in all cell types studied. In EA-treated ESCs, AgNOR pattern was similar to the pattern of AgNORs after inhibition of RNA pol I by actinomycin D. Together, inhibitory effect of EA on arginine methylation and effect on related morphological parameters was especially observed in compartment of nucleoli
Lysine methyltransferase inhibitors: where we are now.
No full textProtein lysine methyltransferases constitute a large family of epigenetic writers which catalyse the transfer of a methyl group from the cofactor S-adenosyl-L-methionine to histone and non-histone specific substrates. Alterations in the expression and activity of these proteins have been linked to the insurgence and progress of several diseases, including cancer, neurological disorders, and growing defects, hence they represent interesting targets for new therapeutical approaches. Over the past two decades, the identification of modulators of lysine methyltransferases has increased tremendously, clarifying the role of these proteins in different physio-pathological states. The aim of this review is to furnish an updated outlook about the protein lysine methyltransferases disclosed modulators, reporting their potency, the mechanism of action and their eventual use in clinical and preclinical studies
Use of Microscale Thermophoresis (MST) for Studying binding interactions of PRSet-7/SETD8 with small molecule specific inhibitors EPI-9 and EPI-23.
No full textHistone methylation plays a key role in establishing and maintaining stable gene expression patterns during cellular differentiation and embryonic development. Considering that a number of small molecules identified as modulators of methyltransferases by high-throughput screening were dyes or derivatives, a small focused library of dye-like compounds was prepared and the small molecules synthesized were pre-screened for potential inhibition of histone lysine methyltransferases (HKMT) using in vitro HMT assays. Two compounds, EPI-
9 and EPI-23, showed low IC50 values against nucleosomal HKMT PR-Set7. Prompted by our interest in the study of small molecule modulators of these epigenetic targets, we applied MST (Microscale Thermophoresis) to the investigation of the interaction of PRset7 with small molecule ligands EPI-9 and EPI-23. Microscale thermophoresis (MST) is a new method that enables the quantitative analysis of molecular interactions in solution. MST is the directed movement of particles in a microscopic temperature gradient: any change of the hydration
shell of biomolecules due to changes in their structure/conformation results in a relative change of movement along the temperature gradient and is used to determine binding affinities, binding kinetics and activity kinetics. Events such as the binding of small molecules to a target can be monitored by this tecnique
Progress in the Development of Lysine Methyltransferase SETD8 Inhibitors
No full textSETD8/SET8/Pr-SET7/KMT5A is the only known lysine methyltransferase that monomethylates lysine 20 of histone H4 (H4K20) in vivo. The methyltransferase activity of SETD8 has been implicated in many essential cellular processes, including DNA replication, DNA damage response, transcription modulation, and cell cycle regulation. In addition to H4K20, SETD8 monomethylates non-histone substrates including proliferating cell nuclear antigen and p53. During the past decade, different structural classes of inhibitors targeting various lysine methyltransferases have been designed and developed. However, the development of SETD8 inhibitors is still in its infancy. This review covers the progress made to date in inhibiting the activity of SETD8 by small molecules, with an emphasis on their discovery, selectivity over other methyltransferases, and cellular activity
Inside Cover: Identification of Structural Features of 2-Alkylidene-1,3-Dicarbonyl Derivatives that Induce Inhibition and/or Activation of Histone Acetyltransferases KAT3B/p300 and KAT2B/PCAF (ChemMedChem 1/2015)
No full textThe inside cover picture shows the modulation of lysine acetyltransferase (KAT) activity by SPV106 (yellow). By manipulating the structural features of SPV106, different activity profiles—from pure PCAF (top left) activator, pan inhibitor, or mixed PCAF activator/p300 (bottom right) inhibitor—were obtained. The reported compounds represent useful chemical tools for mechanistic studies of histone H3 (lime) or H4 (orange) acetylation (Ac groups shown as purple spheres) and its implications in physiological and pathological processes. For more details, see the Full Paper by Alessandra Tosco, Gianluca Sbardella et al. on p. 144 ff
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