• 제목/요약/키워드: high-throughput screening

검색결과 182건 처리시간 0.036초

Integrated Quantitative Phosphoproteomics and Cell-Based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-Related Phosphorylation Sites

  • Kwon, Hye Kyeong;Choi, Hyunwoo;Park, Sung-Gyoo;Park, Woo Jin;Kim, Do Han;Park, Zee-Yong
    • Molecules and Cells
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    • 제44권7호
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    • pp.500-516
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    • 2021
  • Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.

Fluorescence-based Assay System for Endocannabinoid Degradation Enzyme, Fatty Acid Amide Hydrolase

  • ;;;길성호
    • 대한의생명과학회지
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    • 제16권4호
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    • pp.279-285
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    • 2010
  • Endogenous cannabinoids (endocannabinoids) display various pharmacological effects including pain control, anti-inflammation, and neuroprotection. The synthesis and release of endocannabinoids are regulated under both physiological and pathological conditions. The main degrading enzyme of endocannabinoid is fatty acid amide hydrolase (FAAH). Therefore we have developed the fluorescence-based assay system for FAAH. We established stable CosM6 cell lines expressing human FAAH. We also synthesized 2-oxo-2H-chromen-7-yl decanoate (DAEC) as a fluorogenic substrate for FAAH. When crude membrane extracts stably expressing FAAH was incubated with DAEC at $25^{\circ}C$, FAAH reacted specifically to DAEC and catalyzes the hydrolysis of DAEC into decanoic acid and highly fluorescent coumarin. Furthermore, the serin hydrolase inhibitor, phenylmethanesulfonylfluoride, inhibited the coumarin release to the reaction buffer in concentration dependent manner. This assay system is suitable for high-throughput screening since this system has simple experimental procedure and measurement method.

A Neutravidin-based Assay for Reverse Transcriptase Suitable for High Throughput Screening of Retroviral Activity

  • Brennan, Lyndall E.;Sune, Carlos;Klimkait, Thomas
    • BMB Reports
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    • 제35권3호
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    • pp.262-266
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    • 2002
  • A non-isotopic neutravidin-based reverse transcriptase (RT) assay adapted for high throughput screening of HIV activity is described. Using a 96-well microtitre plate, HIV particles are lysed and the RT enzyme released into a reaction mixture containing poly(A) RNA, biotinylated oligo d(T) and fluorescein-labelled dUTP (FI-dUTP). With poly(A) as a template and oligo d(T) as primer, the viron RT incorporates FI-dUTP into an elongating DNA strand. The resulting product is captured on a neutravidin-coated 96-well plate and the unincorporated nucleotides removed by a series of washing steps. A simple ELISA is subsequently performed using a monoclonal antifluorescein antibody conjugated to alkaline phosphatase. Quantification of RT activity is facilitated by a colorimetric readout. The assay was validated in the context of a diagnostic HIV-1 phenotyping assay. Using supernatants from HIV-1 infected lymphocyte cultures the assay was shown to be as sensitive as a radioactive assay and the RT activity correlated well with levels of cell-asociated HIV-p24. Importantly, even minor reductions of RT activity by virus variants with reduced fitness could be distinguished.

Identification of Novel Irreversible Inhibitors of UDP-N-Acetylglucosamine Enolpyruvyl Transferase (MurA) from Haemophilus influenzae

  • Han, Seong-Gu;Lee, Won-Kyu;Jin, Bong-Suk;Lee, Ki-In;Lee, Hyeong Ho;Yu, Yeon Gyu
    • Journal of Microbiology and Biotechnology
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    • 제23권3호
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    • pp.329-334
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    • 2013
  • Uridinediphospho-N-acetylglucosamine enolpyruvyl transferase (MurA, E.C. 2.5.1.7) is an essential bacterial enzyme that catalyzes the first step of the cell wall biosynthetic pathway, which involves the transfer of an enolpyruvyl group from phosphoenolpyruvate to uridinediphospho-Nacetylglucosamine. In this study, novel inhibitors of Haemophilus influenzae MurA (Hi MurA) were identified using high-throughput screening of a chemical library from the Korea Chemical Bank. The identified compounds contain a quinoline moiety and have much lower effective inhibitory concentrations ($IC_{50}$) than fosfomycin, a wellknown inhibitor of MurA. These inhibitors appear to covalently modify the sulfhydryl group of the active site cysteine (C117), since the C117D mutant Hi MurA was not inhibited by these compounds and excess dithiothreitol abolished their inhibitory activities. The increased mass value of Hi MurA after treatment with the identified inhibitor further confirmed that the active-site cysteine residue of Hi MurA is covalently modified by the inhibitor.