- Stereospecific modulation of dimeric rhodopsin
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The classic concept that GPCRs function as monomers has been challenged by the emerging evidence of GPCR dimerization and oligomerization. Rhodopsin (Rh) is the only GPCR whose native oligomeric arrangement was revealed by atomic force microscopy demonstrating that Rh exists as a dimer. However, the role of Rh dimerization in retinal physiology is currently unknown. In this study, we identified econazole and sulconazole, two small molecules that disrupt Rh dimer contacts, by implementing a cell-based high-throughput screening assay. Racemic mixtures of identified lead compounds were separated and tested for their stereospecific binding to Rh using UV-visible spectroscopy and intrinsic fluorescence of tryptophan (Trp) 265 after illumination. By following the changes in UV-visible spectra and Trp265 fluorescence in vitro, we found that binding of R-econazole modulates the formation of Meta III and quenches the intrinsic fluorescence of Trp265. In addition, electrophysiological ex vivo recording revealed that R-econazole slows photoresponse kinetics, whereas S-econazole decreased the sensitivity of rods without effecting the kinetics. Thus, this study contributes new methodology to identify compounds that disrupt the dimerization of GPCRs in general and validates the first active compounds that disrupt the Rh dimer specifically.—Getter, T., Gulati, S., Zimmerman, R., Chen, Y., Vinberg, F., Palczewski, K. Stereospecific modulation of dimeric rhodopsin. FASEB J. 33, 9526–9539 (2019). www.fasebj.org.
- Chen, Yuanyuan,Getter, Tamar,Gulati, Sahil,Palczewski, Krzysztof,Vinberg, Frans,Zimmerman, Remy
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p. 9526 - 9539
(2020/02/27)
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- Investigation of multi-target-directed ligands (MTDLs) with butyrylcholinesterase (BuChE) and indoleamine 2,3-dioxygenase 1 (IDO1) inhibition: The design, synthesis of miconazole analogues targeting Alzheimer's disease
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In our endeavor towards the development of potent multi-target ligands for the treatment of Alzheimer's disease, miconazole was identified to show BuChE-IDO1 dual-target inhibitory effects. Morris water maze test indicated that miconazole obviously ameliorated the cognitive function impaired by scopolamine. Furthermore, it showed good safety in primary hepatotoxicity evaluation. Based on these results, we designed, synthesized, and evaluated a series of miconazole derivatives as BuChE-IDO1 dual-target inhibitors. Out of the 12 compounds, 5i and 5j exhibited the best potency in enzymatic evaluation, thus were selected for subsequent behavioral study, in which the two compounds exerted much improved effect than tacrine. Meanwhile, 5i and 5j displayed no apparent hepatotoxicity. The results suggest that miconazole analogue offers an attractive starting point for further development of new BuChE-IDO1 dual-target inhibitors against Alzheimer's disease.
- Lu, Xin,He, Si-yu,Li, Qi,Yang, Hongyu,Jiang, Xueyang,Lin, Hongzhi,Chen, Yao,Qu, Wei,Feng, Feng,Bian, Yaoyao,Zhou, You,Sun, Haopeng
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p. 1665 - 1674
(2018/02/23)
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- HPLC method for separating enantiomers of imidazole derivatives - Antifungal compounds
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The aim of this study was to test separation possibility of enantiomers of nine active substances belonging to imidazole derivatives: bifonazole, butoconazole, econazole, enilconazole, fenticonazole, isoconazole, miconazole, sertaconazole and tioconazole. The study was performed using HPLC method and the CHIRALCEL OJ column (10 μm; 250 × 4.6 mm), the mobile phase flow rate of 0.8 mL/min and detection at 220 nm. Mobile phases containing hexane and the following modifiers: alcohols (2-propanol, ethanol, methanol) and diethylamine were tested. At first isocratic elution was used but some enantiomers eluted after a long retention time and their peaks were asymmetrical and too wide. Therefore, a gradient elution was developed allowing to obtain satisfactory retention times and other parameters of enentioseparation of the compounds.
- Podolska, Marzena,Bia?ecka, Wanda,Kulik, Anna,Kwiatkowska-Puchniarz, Barbara,Mazurek, Aleksander
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p. 777 - 784
(2017/06/05)
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- Discovery of a small molecule targeting ULK1-modulated cell death of triple negative breast cancer in vitro and in vivo
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UNC-51-like kinase 1 (ULK1) is well-known to initiate autophagy, and the downregulation of ULK1 has been found in most breast cancer tissues. Thus, the activation of ULK1-modulated autophagy could be a promising strategy for breast cancer therapy. In this study, we found that ULK1 was remarkably downregulated in breast cancer tissue samples by The Cancer Genome Atlas (TCGA) analysis and tissue microarray (TMA) analysis, especially in triple negative breast cancer (TNBC). To design a ULK1 agonist, we integrated in silico screening and chemical synthesis to acquire a series of small molecule candidates. After rounds of kinase and anti-proliferative activity screening, we discovered the small molecule, LYN-1604, to be the best candidate for a ULK1 agonist. Additionally, we identified that three amino acid residues (LYS50, LEU53, and TYR89) were key to the activation site of LYN-1604 and ULK1 by site-directed mutagenesis and biochemical assays. Subsequently, we demonstrated that LYN-1604 could induce cell death, associated with autophagy by the ULK complex (ULK1-mATG13-FIP200-ATG101) in MDA-MB-231 cells. To further explore LYN-1604-induced autophagic mechanisms, we found some potential ULK1 interactors, such as ATF3, RAD21, and caspase3, by performing comparative microarray analysis. Intriguingly, we found that LYN-1604 induced cell death involved in ATF3, RAD21, and caspase3, accompanied by autophagy and apoptosis. Moreover, we demonstrated that LYN-1604 has potential for good therapeutic effects on TNBC by targeting ULK1-modulated cell death in vivo; thus making this ULK1 agonist a novel potential small-molecule drug candidate for future TNBC therapy.
- Zhang, Lan,Fu, Leilei,Zhang, Shouyue,Zhang, Jin,Zhao, Yuqian,Zheng, Yaxin,He, Gu,Yang, Shengyong,Ouyang, Liang,Liu, Bo
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p. 2687 - 2701
(2017/04/06)
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- Asymmetric chemoenzymatic synthesis of miconazole and econazole enantiomers. the importance of chirality in their biological evaluation
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A simple and novel chemoenzymatic route has been applied for the first time in the synthesis of miconazole and econazole single enantiomers. Lipases and oxidoreductases have been tested in stereoselective processes; the best results were attained with oxidoreductases for the introduction of chirality in an adequate intermediate. The behaviors of a series of ketones and racemic alcohols in bioreductions and acetylation procedures, respectively, have been investigated; the best results were found with alcohol dehydrogenases A and T, which allowed the production of (R)-2-chloro-1-(2,4-dichlorophenyl)ethanol in enantiopure form under very mild reaction conditions. Final chemical modifications have been performed in order to isolate the target fungicides miconazole and econazole both as racemates and as single enantiomers. Biological evaluation of the racemates and single enantiomers has shown remarkable differences against the growth of several microorganisms; while (R)-miconazole seemed to account for most of the biological activity of racemic miconazole on all the strains tested, both enantiomers of econazole showed considerable biological activities. In this manner, (R)-econazole showed higher values against Candida krusei, while higher values were observed for (S)-econazole against Cryptococcus neoformans, Penicillium chrysogenum, and Aspergillus niger.
- Mangas-Sanchez, Juan,Busto, Eduardo,Gotor-Fernandez, Vicente,Malpartida, Francisco,Gotor, Vicente
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p. 2115 - 2122
(2011/05/19)
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