30 results on '"Sijun Pan"'
Search Results
2. Mitochondria‐Targeting BODIPY Probes for Imaging of Reactive Oxygen Species
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Yingsong Ye, Jiali Sun, Fang Tang, Ruijie Xie, Hui Wang, Aixiang Ding, Sijun Pan, and Lin Li
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BODIPY ,disease diagnosis ,fluorescence ,mitochondrion ,reactive oxygen species ,Technology (General) ,T1-995 ,Science - Abstract
Abstract Reactive oxygen species (ROSs) are an important class of signaling molecules that play a critical role in regulating physiological processes in the human body. Mitochondria are the primary site of ROSs production, and abnormal concentrations of ROSs can lead to the malignant proliferation of cells, resulting in diseases. Therefore, it is crucial to detect ROSs in mitochondria. Fluorometric methods have gained significant attention from scientists because of their ease of observation, simplicity of operation, and noninvasiveness. Among the fluorescent dyes, boron‐dipyrromethene (BODIPY) stands out for its high quantum yield, large molar extinction coefficient, and excellent chemical stability, making it widely used in fluorescent imaging. The common design principle of fluorescent probe for the detection of ROSs includes photo‐induced electron transfer, intramolecular charge transfer, and fluorescence resonance energy transfer. This paper provides an overview of BODIPY‐based fluorescent probes designed for imaging ROSs in mitochondria, covering the sensing mechanisms, molecular engineering strategies, and recent advancements. Additionally, the review provides insight into the potential clinical applications of mitochondria‐targeting BODIPY probes in disease diagnosis.
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- 2023
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3. Efficacy of intravenous plus intrathecal/intracerebral ventricle injection of polymyxin B for post-neurosurgical intracranial infections due to MDR/XDR Acinectobacter baumannii: a retrospective cohort study
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Sijun Pan, Xiaofang Huang, Yesong Wang, Li Li, Changyun Zhao, Zhongxiang Yao, Wei Cui, and Gensheng Zhang
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Acinetobacter Baumannii ,Polymyxin B ,Intrathecal injection ,Intracerebral ventricle injection ,Multidrug resistance ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Post-neurosurgical intracranial infections caused by multidrug-resistant or extensively drug-resistant Acinetobacter baumannii are difficult to treat and associated with high mortality. In this study, we analyzed the therapeutic efficacy of intravenous combined with intrathecal/intracerebral ventricle injection of polymyxin B for this type of intracranial infection. Methods This retrospective study was conducted from January 2013 to September 2017 at the Second Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou,China) and included 61 cases for which cerebrospinal fluid (CSF) cultures were positive for multidrug-resistant or extensively drug-resistant A. baumannii after a neurosurgical operation. Patients treated with intravenous and intrathecal/intracerebral ventricle injection of polymyxin B were assigned to the intrathecal/intracerebral group, and patients treated with other antibiotics without intrathecal/intracerebral injection were assigned to the intravenous group. Data for general information, treatment history, and the results of routine tests and biochemistry indicators in CSF, clinical efficiency, microbiological clearance rate, and the 28-day mortality were collected and analyzed. Results The rate of multidrug-resistant or extensively drug-resistant A. baumannii infection among patients who experienced an intracranial infection after a neurosurgical operation was 33.64% in our hospital. The isolated A. baumannii were resistant to various antibiotics, and most seriously to carbapenems (100.00% resistance rate to imipenem and meropenem), cephalosporins (resistance rates of 98.38% to cefazolin, 100.00% to ceftazidime, 100.00% to cefatriaxone, and 98.39% to cefepime). However, the isolated A. baumannii were completely sensitive to polymyxin B (sensitivity rate of 100.00%), followed by tigecycline (60.66%) and amikacin (49.18%). No significant differences in basic clinical data were observed between the two groups. Compared with the intravenous group, the intrathecal/intracerebral group had a significantly lower 28-day mortality (55.26% vs. 8.70%, P = 0.01) and higher rates of clinical efficacy and microbiological clearance (95.65% vs. 23.68%, P
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- 2018
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4. Correction to: Efficacy of intravenous plus intrathecal/intracerebral ventricle injection of polymyxin B for post-neurosurgical intracranial infections due to MDR/XDR Acinectobacter baumannii: a retrospective cohort study
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Sijun Pan, Xiaofang Huang, Yesong Wang, Li Li, Changyun Zhao, Zhongxiang Yao, Wei Cui, and Gensheng Zhang
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Infectious and parasitic diseases ,RC109-216 - Abstract
The original article [1] contains an error in the Safety analysis sub-section of the results regarding the reported mean creatinine level.
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- 2019
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5. A fluorogenic-inhibitor-based probe for profiling and imaging of monoamine oxidase A in live human glioma cells and clinical tissues
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Haixiao Fang, Panpan Li, Congzhen Shen, Fang Tang, Aixiang Ding, Hua Bai, Bo Peng, Xuekang Yang, Zhengqiu Li, Kai Huang, Sijun Pan, Lin Li, and Wei Huang
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General Chemistry - Published
- 2023
6. A novel pyrimidine-based two-photon fluorogenic probe for rapidly visualizing nitroreductase activity in hypoxic cancer cells and in vivo
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Jia Zhou, Songjie Fang, Duoteng Zhang, Yunwei Qu, Lan Wang, Sijun Pan, Lin Li, Jie Li, Wei Du, and Qiong Wu
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Materials Chemistry ,Metals and Alloys ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Instrumentation ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2023
7. Blood-brain barrier (BBB)-on-a-chip: a promising breakthrough in brain disease research
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Bo Peng, Shiping Hao, Ziqiu Tong, Hua Bai, Sijun Pan, Kah-Leong Lim, Lin Li, Nicolas H. Voelcker, and Wei Huang
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Blood-Brain Barrier ,Brain Neoplasms ,Lab-On-A-Chip Devices ,Biomedical Engineering ,Tumor Microenvironment ,Brain ,Humans ,Bioengineering ,Biological Transport ,General Chemistry ,Biochemistry - Abstract
The blood-brain barrier (BBB) represents a key challenge in developing brain-penetrating therapeutic molecules. BBB dysfunction is also associated with the onset and progression of various brain diseases. The BBB-on-a-chip (μBBB), an organ-on-chip technology, has emerged as a powerful
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- 2022
8. A hydrogel-based mechanical metamaterial for the interferometric profiling of extracellular vesicles in patient samples
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Haitao Zhao, Sijun Pan, Auginia Natalia, Xingjie Wu, Chin-Ann J. Ong, Melissa C. C. Teo, Jimmy B. Y. So, and Huilin Shao
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Biomedical Engineering ,Medicine (miscellaneous) ,Bioengineering ,Computer Science Applications ,Biotechnology - Abstract
The utility of mechanical metamaterials for biomedical applications has seldom been explored. Here we show that a metamaterial that is mechanically responsive to antibody-mediated biorecognition can serve as an optical interferometric mask to molecularly profile extracellular vesicles in ascites fluid from patients with cancer. The metamaterial consists of a hydrogel responsive to temperature and redox activity functionalized with antibodies to surface biomarkers on extracellular vesicles, and is patterned into micrometric squares on a gold-coated glass substrate. Through plasmonic heating, the metamaterial is maintained in a transition state between a relaxed form and a buckled state. Binding of extracellular vesicles from the patient samples to the antibodies on the hydrogel causes it to undergo crosslinking, induced by free radicals generated via the activity of horseradish peroxidase conjugated to the antibodies. Hydrogel crosslinking causes the metamaterial to undergo fast chiral re-organization, inducing amplified changes in its mechanical deformation and diffraction patterns, which are detectable by a smartphone camera. The mechanical metamaterial may find broad utility in the sensitive optical immunodetection of biomolecules.
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- 2020
9. Extracellular vesicle drug occupancy enables real-time monitoring of targeted cancer therapy
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Tze Ping Loh, Auginia Natalia, John Kit Chung Tam, Carine Z. J. Lim, Yan Zhang, Balram Chowbay, Huilin Shao, Sijun Pan, and Nicholas R. Y. Ho
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Drug ,Disease status ,Lung Neoplasms ,media_common.quotation_subject ,Biomedical Engineering ,Cancer therapy ,Bioengineering ,Antineoplastic Agents ,02 engineering and technology ,Computational biology ,Biosensing Techniques ,Signal-To-Noise Ratio ,010402 general chemistry ,01 natural sciences ,Erlotinib Hydrochloride ,Extracellular Vesicles ,Cell Line, Tumor ,medicine ,Biomarkers, Tumor ,Humans ,General Materials Science ,In patient ,Molecular Targeted Therapy ,Electrical and Electronic Engineering ,media_common ,Small volume ,business.industry ,Cancer ,Extracellular vesicle ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,medicine.disease ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,ErbB Receptors ,In situ analysis ,Case-Control Studies ,Feasibility Studies ,0210 nano-technology ,business - Abstract
Current technologies to measure drug–target interactions require complex processing and invasive tissue biopsies, limiting their clinical utility for cancer treatment monitoring. Here we develop an analytical platform that leverages circulating extracellular vesicles (EVs) for activity-based assessment of tumour-specific drug–target interactions in patient blood samples. The technology, termed extracellular vesicle monitoring of small-molecule chemical occupancy and protein expression (ExoSCOPE), utilizes bio-orthogonal probe amplification and spatial patterning of molecular reactions within matched plasmonic nanoring resonators to achieve in situ analysis of EV drug dynamics. It measures changes in drug occupancy and protein composition in molecular subpopulations of EVs. When used to monitor various targeted therapies, the ExoSCOPE revealed EV signatures that closely reflected cellular treatment efficacy. We further applied the technology for clinical cancer diagnostics and treatment monitoring. Using a small volume of blood, the ExoSCOPE accurately classified disease status and rapidly distinguished between targeted treatment outcomes, within 24 h after treatment initiation. In this work, the authors develop a platform that leverages extracellular vesicles to measure drug–target engagement and apply it to monitor the outcomes of targeted treatments in lung cancer patients.
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- 2020
10. A Vinyl Sulfone-Based Fluorogenic Probe Capable of Selective Labeling of PHGDH in Live Mammalian Cells
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Jun-Seok Lee, Jiaqi Fu, Sijun Pan, Si Si Liew, Shao Q. Yao, Danyang Wang, and Se-Young Jang
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Dehydrogenase ,010402 general chemistry ,01 natural sciences ,Fluorescence ,Catalysis ,Live cell imaging ,Chlorocebus aethiops ,Animals ,Humans ,Moiety ,Organic chemistry ,Sulfones ,Phosphoglycerate dehydrogenase ,Phosphoglycerate Dehydrogenase ,Fluorescent Dyes ,COS cells ,Molecular Structure ,Chemistry ,010405 organic chemistry ,fungi ,Hep G2 Cells ,General Chemistry ,General Medicine ,Small molecule ,In vitro ,0104 chemical sciences ,Molecular Docking Simulation ,Spectrometry, Fluorescence ,Biochemistry ,COS Cells ,MCF-7 Cells - Abstract
Chemical probes are powerful tools for interrogating small molecule-target interactions. With additional fluorescence Turn-ON functionality, such probes might enable direct measurements of target engagement in live mammalian cells. DNS-pE (and its terminal alkyne-containing version DNS-pE2) is the first small molecule that can selectively label endogenous 3-phosphoglycerate dehydrogenase (PHGDH) from various mammalian cells. Endowed with an electrophilic vinyl sulfone moiety that possesses fluorescence-quenching properties, DNS-pE/DNS-pE2 became highly fluorescent only upon irreversible covalent modification of PHGDH. With an inhibitory property (in vitro Ki =7.4 μm) comparable to that of known PHGDH inhibitors, our probes thus offer a promising approach to simultaneously image endogenous PHGDH activities and study its target engagement in live-cell settings.
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- 2017
11. A Suite of 'Minimalist' Photo-Crosslinkers for Live-Cell Imaging and Chemical Proteomics: Case Study with BRD4 Inhibitors
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Sijun Pan, Se-Young Jang, Si Si Liew, Zhengqiu Li, Shao Q. Yao, Jun-Seok Lee, and Danyang Wang
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Proteomics ,BRD4 ,010405 organic chemistry ,Chemistry ,Nuclear Proteins ,Cell Cycle Proteins ,General Medicine ,General Chemistry ,Photochemical Processes ,010402 general chemistry ,01 natural sciences ,Small molecule ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Cross-Linking Reagents ,Biochemistry ,Live cell imaging ,Stable isotope labeling by amino acids in cell culture ,Diazirine ,Humans ,Bioorthogonal chemistry ,Transcription Factors - Abstract
Affinity-based probes (AfBPs) provide a powerful tool for large-scale chemoproteomic studies of drug-target interactions. The development of high-quality probes capable of recapitulating genuine drug-target engagement, however, could be challenging. "Minimalist" photo-crosslinkers, which contain an alkyl diazirine group and a chemically tractable tag, could alleviate such challenges, but few are currently available. Herein, we have developed new alkyl diazirine-containing photo-crosslinkers with different bioorthogonal tags. They were subsequently used to create a suite of AfBPs based on GW841819X (a small molecule inhibitor of BRD4). Through in vitro and in situ studies under conditions that emulated native drug-target interactions, we have obtained better insights into how a tag might affect the probe's performance. Finally, SILAC-based chemoproteomic studies have led to the discovery of a novel off-target, APEX1. Further studies showed GW841819X binds to APEX1 and caused up-regulation of endogenous DNMT1 expression under normoxia conditions.
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- 2017
12. A chemoselective cleavable fluorescence turn-ON linker for proteomic studies
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Shubo Du, Se-Young Jang, Shao Q. Yao, Si Si Liew, Sijun Pan, Jingyan Ge, and Jun-Seok Lee
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Proteomics ,Proteome ,010402 general chemistry ,Cleavage (embryo) ,01 natural sciences ,Fluorescence ,Catalysis ,Turn (biochemistry) ,Materials Chemistry ,Organic chemistry ,Molecule ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Metals and Alloys ,General Chemistry ,Combinatorial chemistry ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Proteome profiling ,Ceramics and Composites ,Linker - Abstract
We have developed a trifunctional cleavable fluorescence turn-ON linker for chemoproteomic applications. This novel linker, which became highly fluorescent only upon cleavage of the azo bond, was successfully used for in situ proteome profiling/target identification and studies on newly synthesised proteomes.
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- 2017
13. Fluorescent Probes for Single-Step Detection and Proteomic Profiling of Histone Deacetylases
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Quan Hao, Danyang Wang, Shao Q. Yao, Yi Wang, Haipeng Lei, Ganchao Chen, Jingyan Ge, Sijun Pan, Hongyan Sun, Huatang Zhang, Bo Peng, Yusheng Xie, and Lanfang Chen
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Proteomics ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Histone Deacetylases ,Catalysis ,Residue (chemistry) ,Colloid and Surface Chemistry ,Humans ,Moiety ,Fluorescent Dyes ,chemistry.chemical_classification ,Molecular Structure ,biology ,010405 organic chemistry ,Proteomic Profiling ,General Chemistry ,Fluorescence ,0104 chemical sciences ,Enzyme ,Histone ,chemistry ,biology.protein ,Amine gas treating - Abstract
Histone deacetylases (HDACs) play important roles in regulating various physiological and pathological processes. Developing fluorescent probes capable of detecting HDAC activity can help further elucidate the roles of HDACs in biology. In this study, we first developed a set of activity-based fluorescent probes by incorporating the Kac residue and the O-NBD group. Upon enzymatic removal of the acetyl group in the Kac residue, the released free amine reacted intramolecularly with the O-NBD moiety, resulting in turn-on fluorescence. These designed probes are capable of detecting HDAC activity in a continuous fashion, thereby eliminating the extra step of fluorescence development. Remarkably, the amount of turn-on fluorescence can be as high as 50-fold, which is superior to the existing one-step HDAC fluorescent probes. Inhibition experiments further proved that the probes can serve as useful tools for screening HDAC inhibitors. Building on these results, we moved on and designed a dual-purpose fluorescent probe by introducing a diazirine photo-cross-linker into the probe. The resulting probe was not only capable of reporting enzymatic activity but also able to directly identify and capture the protein targets from the complex cellular environment. By combining a fluorometric method and in-gel fluorescence scanning technique, we found that epigenetic readers and erasers can be readily identified and differentiated using a single probe. This is not achievable with traditional photoaffinity probes. In light of the prominent properties and the diverse functions of this newly developed probe, we envision that it can provide a robust tool for functional analysis of HDACs and facilitate future drug discovery in epigenetics.
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- 2016
14. Expanding the 'minimalist' small molecule tagging approach to different bioactive compounds
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Shikun Nie, Chaonan Yuan, Qing Zhu, Wenjie Lang, Jie Luo, Jian Liu, Biwei Zhu, Jun-Seok Lee, Sijun Pan, and Jingyan Ge
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Proteomics ,Chemistry ,Cellular imaging ,Organic Chemistry ,Optical Imaging ,Computational biology ,Hep G2 Cells ,Biochemistry ,Small molecule ,Recombinant Proteins ,Neoplasm Proteins ,Protein profiling ,Small Molecule Libraries ,Humans ,Camptothecin ,Physical and Theoretical Chemistry - Abstract
"Minimalist" small molecule tagging (MSMT) is a promising approach that easily converts bioactive compounds into affinity-based probes (AfBPs) for proteomic studies. In this work, seven bioactive compounds targeting diversified protein classes were installed with "minimalist" linkers through common reactions to generate the corresponding AfBPs. These probes were evaluated for cell-based protein profiling and target validation. Among them, the entinostat-derived probe EN and the camptothecin-derived probe CA were further utilized in cellular imaging and SILAC-based large-scale target identification. Our extensive studies suggest that the "minimalist" small molecule tagging approach could be expanded to different classes of bioactive compounds for modification into AfBPs as a dual functional tool for both proteomics and cellular imaging.
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- 2019
15. Live-cell imaging and profiling of c-Jun N-terminal kinases using covalent inhibitor-derived probes
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Jingyan Ge, Linghui Qian, Lin Li, Sijun Pan, Shao Q. Yao, and Jun-Seok Lee
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Cellular functions ,Catalysis ,Small Molecule Libraries ,Optical imaging ,Live cell imaging ,Materials Chemistry ,Humans ,Protein Kinase Inhibitors ,Fluorescent Dyes ,biology ,Molecular Structure ,Chemistry ,Kinase ,Optical Imaging ,Metals and Alloys ,JNK Mitogen-Activated Protein Kinases ,General Chemistry ,Fluorescence ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biochemistry ,c-Jun N-terminal kinases ,Covalent bond ,Ceramics and Composites ,biology.protein ,HeLa Cells - Abstract
c-Jun N-terminal kinases (JNKs) are involved in critical cellular functions. Herein, small-molecule JNK-targeting probes are reported based on a covalent inhibitor. Together with newly developed two-photon fluorescence Turn-ON reporters and chemoproteomic studies, we showed that some probes may be suitable for live-cell imaging and profiling of JNKs.
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- 2019
16. Puromycin Analogues Capable of Multiplexed Imaging and Profiling of Protein Synthesis and Dynamics in Live Cells and Neurons
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Shao Q. Yao, Thorsten Wohland, Chengwu Zhang, Sijun Pan, Xue Wen Ng, Bo Peng, Lin Li, Kah-Leong Lim, Shubo Du, Danyang Wang, and Jingyan Ge
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Neurons ,0301 basic medicine ,Cellular process ,Protein dynamics ,Direct imaging ,Fluorescence correlation spectroscopy ,General Chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,03 medical and health sciences ,030104 developmental biology ,Biochemistry ,chemistry ,Puromycin ,Protein Biosynthesis ,Proteome ,Protein biosynthesis ,Humans ,Bioorthogonal chemistry ,HeLa Cells - Abstract
Newly synthesized proteins constitute an important subset of the proteome involved in every cellular process, yet existing chemical tools used to study them have major shortcomings. Herein we report a suite of cell-permeable puromycin analogues capable of being metabolically incorporated into newly synthesized proteins in different mammalian cells, including neuronal cells. Subsequent labeling with suitable bioorthogonal reporters, in both fixed and live cells, enabled direct imaging and enrichment of these proteins. By taking advantage of the mutually orthogonal reactivity of these analogues, we showed multiplexed labeling of different protein populations, as well as quantitative measurements of protein dynamics by fluorescence correlation spectroscopy, could be achieved in live-cell environments.
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- 2016
17. Target identification of natural products and bioactive compounds using affinity-based probes
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Chenyu Wang, Hailong Zhang, Sijun Pan, Samantha C. L. Yao, and Shao Q. Yao
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Proteomics ,Biological Products ,Natural product ,Molecular Structure ,010405 organic chemistry ,Organic Chemistry ,Computational biology ,Biology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Bioactive compound ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Drug Design ,Drug Discovery ,Humans - Abstract
Covering: 2010 to 2014.Advances in isolation, synthesis and screening strategies have made many bioactive substances available. However, in most cases their putative biological targets remain unknown. Herein, we highlight recent advances in target identification of natural products and bioactive compounds by using affinity-based probes. Aided by photoaffinity labelling, this strategy can capture potential cellular targets (on and off) of a natural product or bioactive compound in live cells directly, even when the compound-target interaction is reversible with moderate affinity. The knowledge of these targets may help uncover molecular pathways and new therapeutics for currently untreatable diseases. In this highlight, we will introduce the development of various photoactivatable groups, their synthesis and applications in target identification of natural products and bioactive compounds, with a focus on work done in recent years and from our laboratory. We will further discuss the strengths and weaknesses of each group and the outlooks for this novel proteome-wide profiling strategy.
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- 2016
18. [Impact of permissive underfeeding versus standard enteral feeding on outcomes in critical patients requiring mechanical ventilation: a prospective randomized controlled study]
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Nianbin, Ma, Mingfu, Shen, Zhen, Wan, Sijun, Pan, Xian, Liu, and Zhongxiang, Yao
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Calcitonin ,Intensive Care Units ,Enteral Nutrition ,Critical Illness ,Humans ,Prospective Studies ,Length of Stay ,Respiration, Artificial - Abstract
To compare the impact of permissive underfeeding versus standard enteral feeding on outcomes in critical patients requiring mechanical ventilation (MV).A prospective randomized controlled study was conducted. Eighty-two patients requiring MV admitted to intensive care unit (ICU) of Anji People's Hospital from January 2015 to March 2017 were enrolled, and they were randomly divided into the permissive underfeeding group (n = 40, non-protein heat was 52.3-62.8 kJ×kgCompared with before treatment, the levels of serum PA (mg/L) and ALB (g/L) were significantly increased, the levels of PCT (ng/L) and hs-CRP (mg/L) were significantly decreased at 7 days after treatment in both groups [permissive underfeeding group: PA was 127.42±65.83 vs. 80.92±60.14, ALB was 30.16±4.32 vs. 25.36±6.21, PCT was 375.8±227.2 vs. 762.3±314.5, hs-CRP was 32.19±7.53 vs. 120.48±60.24; standard enteral feeding group: PA was 132.56±61.32 vs. 86.78±47.06, ALB was 31.25±4.63 vs. 26.71±5.48, PCT was 412.1±323.4 vs. 821.7±408.6, hs-CRP was 35.86±5.69 vs. 116.38±72.16, all P0.05], but there was no significant difference in PA, ALB, PCT or hs-CRP at 7 days after treatment between two groups (all P0.05). There was no significant difference in the duration of MV, length of ICU stay, 28-day mortality or ICU-associated infection between two groups [duration of MV (hours): 162.35±20.37 vs. 153.48±18.65, length of ICU stay (days): 7.52±1.61 vs. 6.34±1.87, 28-day mortality: 17.5% vs. 19.0%, ICU-associated infection: 45.0% vs. 47.6%, all P0.05]. Compared with standard enteral feeding, insulin demand was significantly decreased (U/d: 13.68±10.36 vs. 26.24±18.53), and gastrointestinal intolerance was less frequent (32.5% vs. 54.8%) in the permissive underfeeding group (both P0.05). Kaplan-Meier survival curve analysis showed that there was no significant difference between the two groups (χThe curative effect and prognosis of MV severe patients receiving permissive underfeeding are similar to those of standard enteral feeding, but it can reduce the dosage of insulin with better gastrointestinal tolerance.
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- 2018
19. Efficacy of intravenous plus intrathecal/intracerebral ventricle injection of polymyxin B for post-neurosurgical intracranial infections due to MDR/XDR Acinectobacter baumannii: a retrospective cohort study
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Zhongxiang Yao, Sijun Pan, Yesong Wang, Li Li, Gensheng Zhang, Wei Cui, Xiaofang Huang, and Changyun Zhao
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Adult ,Male ,0301 basic medicine ,Microbiology (medical) ,China ,Imipenem ,Cefepime ,030106 microbiology ,Cefazolin ,Microbial Sensitivity Tests ,Tigecycline ,Multidrug resistance ,Meropenem ,lcsh:Infectious and parasitic diseases ,03 medical and health sciences ,0302 clinical medicine ,Drug Resistance, Multiple, Bacterial ,Humans ,Medicine ,Pharmacology (medical) ,lcsh:RC109-216 ,030212 general & internal medicine ,Injections, Spinal ,Aged ,Cerebrospinal Fluid ,Retrospective Studies ,Polymyxin B ,biology ,business.industry ,Research ,Public Health, Environmental and Occupational Health ,Intrathecal injection ,Middle Aged ,biology.organism_classification ,Anti-Bacterial Agents ,Acinetobacter baumannii ,Infusions, Intraventricular ,Treatment Outcome ,Infectious Diseases ,Intracerebral ventricle injection ,Anesthesia ,Injections, Intravenous ,Ceftriaxone ,Female ,business ,Acinetobacter Baumannii ,Acinetobacter Infections ,medicine.drug - Abstract
Background Post-neurosurgical intracranial infections caused by multidrug-resistant or extensively drug-resistant Acinetobacter baumannii are difficult to treat and associated with high mortality. In this study, we analyzed the therapeutic efficacy of intravenous combined with intrathecal/intracerebral ventricle injection of polymyxin B for this type of intracranial infection. Methods This retrospective study was conducted from January 2013 to September 2017 at the Second Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou,China) and included 61 cases for which cerebrospinal fluid (CSF) cultures were positive for multidrug-resistant or extensively drug-resistant A. baumannii after a neurosurgical operation. Patients treated with intravenous and intrathecal/intracerebral ventricle injection of polymyxin B were assigned to the intrathecal/intracerebral group, and patients treated with other antibiotics without intrathecal/intracerebral injection were assigned to the intravenous group. Data for general information, treatment history, and the results of routine tests and biochemistry indicators in CSF, clinical efficiency, microbiological clearance rate, and the 28-day mortality were collected and analyzed. Results The rate of multidrug-resistant or extensively drug-resistant A. baumannii infection among patients who experienced an intracranial infection after a neurosurgical operation was 33.64% in our hospital. The isolated A. baumannii were resistant to various antibiotics, and most seriously to carbapenems (100.00% resistance rate to imipenem and meropenem), cephalosporins (resistance rates of 98.38% to cefazolin, 100.00% to ceftazidime, 100.00% to cefatriaxone, and 98.39% to cefepime). However, the isolated A. baumannii were completely sensitive to polymyxin B (sensitivity rate of 100.00%), followed by tigecycline (60.66%) and amikacin (49.18%). No significant differences in basic clinical data were observed between the two groups. Compared with the intravenous group, the intrathecal/intracerebral group had a significantly lower 28-day mortality (55.26% vs. 8.70%, P = 0.01) and higher rates of clinical efficacy and microbiological clearance (95.65% vs. 23.68%, P
- Published
- 2018
20. 'Minimalist' Cyclopropene-Containing Photo-Cross-Linkers Suitable for Live-Cell Imaging and Affinity-Based Protein Labeling
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Chelsea Y. J. Tan, Lin Li, Zhenkun Na, Danyang Wang, Sijun Pan, Zhengqiu Li, and Shao Q. Yao
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Cyclopropanes ,Cells ,Affinity label ,Biocompatible Materials ,Photoaffinity Labels ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Live cell imaging ,Cell Line, Tumor ,Humans ,Moiety ,biology ,Chemistry ,Drug discovery ,Nuclear Proteins ,Proteins ,Affinity Labels ,General Chemistry ,Cross-Linking Reagents ,Combinatorial chemistry ,Diazirine ,biology.protein ,Bioorthogonal chemistry ,Protein Binding - Abstract
Target identification of bioactive compounds within the native cellular environment is important in biomedical research and drug discovery, but it has traditionally been carried out in vitro. Information about how such molecules interact with their endogenous targets (on and off) is currently highly limited. An ideal strategy would be one that recapitulates protein-small molecule interactions in situ (e.g., in living cells) and at the same time enables enrichment of these complexes for subsequent proteome-wide target identification. Similarly, small molecule-based imaging approaches are becoming increasingly available for in situ monitoring of a variety of proteins including enzymes. Chemical proteomic strategies for simultaneous bioimaging and target identification of noncovalent bioactive compounds in live mammalian cells, however, are currently not available. This is due to a lack of photoaffinity labels that are minimally modified from their parental compounds, yet chemically tractable using copper-free bioorthogonal chemistry. We have herein developed novel minimalist linkers containing both an alkyl diazirine and a cyclopropene. We have shown chemical probes (e.g., BD-2) made from such linkers could be used for simultaneous in situ imaging and covalent labeling of endogenous BRD-4 (an important epigenetic protein) via a rapid, copper-free, tetrazine-cyclopropene ligation reaction (k2 > 5 M(-1) s(-1)). The key features of our cyclopropenes, with their unique C-1 linkage to BRD-4-targeting moiety, are their tunable reactivity and solubility, relative stability, and synthetic accessibility. BD-2, which is a linker-modified analogue of (+)-JQ1 (a recently discovered nanomolar protein-protein-interaction inhibitor of BRD-4), was subsequently used in a cell-based proteome profiling experiment for large-scale identification of potential off-targets of (+)-JQ1. Several newly identified targets were subsequently confirmed by preliminary validation experiments.
- Published
- 2014
21. Discovery of Cell-Permeable Inhibitors That Target the BRCT Domain of BRCA1 Protein by Using a Small-Molecule Microarray
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Zhenkun Na, Mahesh Uttamchandani, Shao Q. Yao, and Sijun Pan
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DNA repair ,DNA damage ,Cell ,Catalysis ,Olaparib ,chemistry.chemical_compound ,medicine ,Humans ,skin and connective tissue diseases ,Polymerase ,biology ,BRCA1 Protein ,Topoisomerase ,General Chemistry ,General Medicine ,Cell cycle ,Molecular biology ,DNA-Binding Proteins ,BRCT domain ,medicine.anatomical_structure ,chemistry ,Tissue Array Analysis ,biology.protein ,Cancer research ,Carrier Proteins ,Protein Binding - Abstract
BRCTs are phosphoserine-binding domains found in proteins involved in DNA repair, DNA damage response and cell cycle regulation. BRCA1 is a BRCT domain-containing, tumor-suppressing protein expressed in the cells of breast and other human tissues. Mutations in BRCA1 have been found in ca. 50% of hereditary breast cancers. Cell-permeable, small-molecule BRCA1 inhibitors are promising anticancer agents, but are not available currently. Herein, with the assist of microarray-based platforms, we have discovered the first cell-permeable protein-protein interaction (PPI) inhibitors against BRCA1. By targeting the (BRCT)2 domain, we showed compound 15 a and its prodrug 15 b inhibited BRCA1 activities in tumor cells, sensitized these cells to ionizing radiation-induced apoptosis, and showed synergistic inhibitory effect when used in combination with Olaparib (a small-molecule inhibitor of poly-ADP-ribose polymerase) and Etoposide (a small-molecule inhibitor of topoisomerase II). Unlike previously reported peptide-based PPI inhibitors of BRCA1, our compounds are small-molecule-like and could be directly administered to tumor cells, thus making them useful for future studies of BRCA1/PARP-related pathways in DNA damage and repair response, and in cancer therapy.
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- 2014
22. Protein-Protein Interaction Inhibitors of BRCA1 Discovered Using Small Molecule Microarrays
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Zhenkun, Na, Sijun, Pan, Mahesh, Uttamchandani, and Shao Q, Yao
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Staining and Labeling ,BRCA1 Protein ,Caspase 3 ,Apoptosis ,Fluorescence Polarization ,Calorimetry ,Crystallography, X-Ray ,Microarray Analysis ,Small Molecule Libraries ,Humans ,Homologous Recombination ,Peptides ,Cell Proliferation ,HeLa Cells ,Protein Binding - Abstract
Microarray screening technology has transformed the life sciences arena over the last decade. The platform is widely used in the area of mapping interaction networks, to molecular fingerprinting and small molecular inhibitor discovery. The technique has significantly impacted both basic and applied research. The microarray platform can likewise enable high-throughput screening and discovery of protein-protein interaction (PPI) inhibitors. Herein we demonstrate the application of microarray-guided PPI inhibitor discovery, using human BRCA1 as an example. Mutations in BRCA1 have been implicated in ~50 % of hereditary breast cancers. By targeting the (BRCT)
- Published
- 2016
23. Protein–Protein Interaction Inhibitors of BRCA1 Discovered Using Small Molecule Microarrays
- Author
-
Shao Q. Yao, Zhenkun Na, Sijun Pan, and Mahesh Uttamchandani
- Subjects
0301 basic medicine ,Microarray ,Microarray analysis techniques ,DNA damage ,Chemistry ,Small Molecule Libraries ,Computational biology ,010402 general chemistry ,01 natural sciences ,Small molecule ,0104 chemical sciences ,Protein–protein interaction ,03 medical and health sciences ,030104 developmental biology ,DNA microarray ,Homologous recombination - Abstract
Microarray screening technology has transformed the life sciences arena over the last decade. The platform is widely used in the area of mapping interaction networks, to molecular fingerprinting and small molecular inhibitor discovery. The technique has significantly impacted both basic and applied research. The microarray platform can likewise enable high-throughput screening and discovery of protein-protein interaction (PPI) inhibitors. Herein we demonstrate the application of microarray-guided PPI inhibitor discovery, using human BRCA1 as an example. Mutations in BRCA1 have been implicated in ~50 % of hereditary breast cancers. By targeting the (BRCT)2 domain, we showed compound 15a and its prodrug 15b inhibited BRCA1 activities in tumor cells. Unlike previously reported peptide-based PPI inhibitors of BRCA1, the compounds identified could be directly administered to tumor cells, thus making them useful in targeting BRCA1/PARP-related pathways involved in DNA damage and repair response, for cancer therapy.
- Published
- 2016
24. In Situ Proteome Profiling and Bioimaging Applications of Small-Molecule Affinity-Based Probes Derived From DOT1L Inhibitors
- Author
-
Hailong Zhang, Biwei Zhu, Chenyu Wang, Shao Q. Yao, Sijun Pan, Jingyan Ge, and Jun-Seok Lee
- Subjects
0301 basic medicine ,Proteomics ,Thermal shift assay ,Methyltransferase ,Proteome ,010402 general chemistry ,01 natural sciences ,Catalysis ,Cell Line ,Histones ,Small Molecule Libraries ,03 medical and health sciences ,Histone H3 ,Humans ,Enzyme Inhibitors ,Chemistry ,Organic Chemistry ,Activity-based proteomics ,General Chemistry ,DOT1L ,Histone-Lysine N-Methyltransferase ,Methyltransferases ,Molecular biology ,Small molecule ,0104 chemical sciences ,Blot ,Molecular Docking Simulation ,030104 developmental biology ,Biochemistry ,Drug Design ,Molecular Probes - Abstract
DOT1L is the sole protein methyltransferase that methylates histone H3 on lysine 79 (H3K79), and is a promising drug target against cancers. Small-molecule inhibitors of DOT1L such as FED1 are potential anti-cancer agents and useful tools to investigate the biological roles of DOT1L in human diseases. FED1 showed excellent in vitro inhibitory activity against DOT1L, but its cellular effect was relatively poor. In this study, we designed and synthesized photo-reactive and "clickable" affinity-based probes (AfBPs), P1 and P2, which were cell-permeable and structural mimics of FED1. The binding and inhibitory effects of these two probes against DOT1L protein were extensively investigated in vitro and in live mammalian cells (in situ). The cellular uptake and sub-cellular localization properties of the probes were subsequently studied in live-cell imaging experiments, and our results revealed that, whereas both P1 and P2 readily entered mammalian cells, most of them were not able to reach the cell nucleus where functional DOT1L resides. This offers a plausible explanation for the poor cellular activity of FED1. Finally with P1/P2, large-scale cell-based proteome profiling, followed by quantitative LC-MS/MS, was carried out to identify potential cellular off-targets of FED1. Amongst the more than 100 candidate off-targets identified, NOP2 (a putative ribosomal RNA methyltransferase) was further confirmed to be likely a genuine off-target of FED1 by preliminary validation experiments including pull-down/Western blotting (PD/WB) and cellular thermal shift assay (CETSA).
- Published
- 2016
25. A small-molecule protein-protein interaction inhibitor of PARP1 that targets its BRCT domain
- Author
-
Han-Ming Shen, Shao Q. Yao, Jun-Seok Lee, Shukie Ng, Bo Peng, Sijun Pan, and Zhenkun Na
- Subjects
chemistry.chemical_classification ,Natural product ,DNA repair ,Gossypol ,Protein Array Analysis ,Stereoisomerism ,General Medicine ,General Chemistry ,Poly(ADP-ribose) Polymerase Inhibitors ,Small molecule ,Catalysis ,Protein–protein interaction ,chemistry.chemical_compound ,Enzyme ,BRCT domain ,PARP1 ,Biochemistry ,chemistry ,Catalytic Domain ,Cancer cell ,Humans ,Protein Interaction Domains and Motifs ,Poly(ADP-ribose) Polymerases ,HeLa Cells ,Protein Binding - Abstract
Poly(ADP-ribose)polymerase-1 (PARP1) is a BRCT-containing enzyme (BRCT = BRCA1 C-terminus) mainly involved in DNA repair and damage response and a validated target for cancer treatment. Small-molecule inhibitors that target the PARP1 catalytic domain have been actively pursued as anticancer drugs, but are potentially problematic owing to a lack of selectivity. Compounds that are capable of disrupting protein-protein interactions of PARP1 provide an alternative by inhibiting its activities with improved selectivity profiles. Herein, by establishing a high-throughput microplate-based assay suitable for screening potential PPI inhibitors of the PARP1 BRCT domain, we have discovered that (±)-gossypol, a natural product with a number of known biological activities, possesses novel PARP1 inhibitory activity both in vitro and in cancer cells and presumably acts through disruption of protein-protein interactions. As the first known cell-permeable small-molecule PPI inhibitor of PAPR1, we further established that (-)-gossypol was likely the causative agent of PARP1 inhibition by promoting the formation of a 1:2 compound/PARP1 complex by reversible formation of a covalent imine linkage.
- Published
- 2014
26. Simultaneous Imaging of Endogenous Survivin mRNA and On-Demand Drug Release in Live Cells by Using a Mesoporous Silica Nanoquencher
- Author
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Jiaqi Fu, Kok Chan Chong, Peiyan Yuan, Changmin Yu, Shao Q. Yao, Shuizhu Wu, Sijun Pan, and Xin Mao
- Subjects
Drug ,Materials science ,010405 organic chemistry ,media_common.quotation_subject ,Cell ,General Chemistry ,Mesoporous silica ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Biomaterials ,medicine.anatomical_structure ,Biochemistry ,Drug delivery ,Survivin ,medicine ,Biophysics ,Dark quencher ,General Materials Science ,Bioorthogonal chemistry ,Cytotoxicity ,Biotechnology ,media_common - Abstract
The design of multifunctional drug delivery systems capable of simultaneous target detection, imaging, and therapeutics in live mammalian cells is critical for biomedical research. In this study, by using mesoporous silica nanoparticles (MSNs) chemically modified with a small-molecule dark quencher, followed by sequential drug encapsulation, MSN capping with a dye-labeled antisense oligonucleotide, and bioorthogonal surface modification with cell-penetrating poly(disulfide)s, the authors have successfully developed the first mesoporous silica nanoquencher (qMSN), characterized by high drug-loading and endocytosis-independent cell uptake, which is able to quantitatively image endogenous survivin mRNA and release the loaded drug in a manner that depends on the survivin expression level in tumor cells. The authors further show that this novel drug delivery system may be used to minimize potential cytotoxicity encountered by many existing small-molecule drugs in cancer therapy.
- Published
- 2017
27. Multiplex imaging and cellular target identification of kinase inhibitors via an affinity-based proteome profiling approach
- Author
-
Piliang Hao, Sijun Pan, Shao Q. Yao, Ying Su, Lin Li, Siu Kwan Sze, Zhengqiu Li, Xiaoyuan Wu, and School of Biological Sciences
- Subjects
Proteomics ,Cyclin-dependent kinase 1 ,Multidisciplinary ,Proteome ,Kinase ,Computational biology ,Biology ,Molecular biology ,Small molecule ,Chromatography, Affinity ,Article ,Science::Biological sciences [DRNTU] ,Molecular Imaging ,Tandem Mass Spectrometry ,Molecular Probes ,Humans ,Multiplex ,Aurora Kinase A ,Molecular Targeted Therapy ,Bioorthogonal chemistry ,Protein Kinase Inhibitors ,Chromatography, Liquid ,HeLa Cells - Abstract
MLN8237 is a highly potent and presumably selective inhibitor of Aurora kinase A (AKA) and has shown promising antitumor activities. Like other kinase inhibitors which target the ATP-binding site of kinases, MLN8237 might be expected to have potential cellular off-targets. Herein, we report the first photoaffinity-based, small molecule AKA probe capable of both live-cell imaging of AKA activities and in situ proteome profiling of potential off-targets of MLN8237 (including AKA-associating proteins). By using two mutually compatible, bioorthogonal reactions (copper-catalyzed azide-alkyne cycloaddition chemistry and TCO-tetrazine ligation), we demostrate small molecule-based multiplex bioimaging for simultaneous in situ monitoring of two important cell-cycle regulating kinases (AKA and CDK1). A broad range of proteins, as potential off-targets of MLN8237 and AKA's-interacting partners, is subsequently identified by affinity-based proteome profiling coupled with large-scale LC-MS/MS analysis. From these studies, we discover novel AKA interactions which were further validated by cell-based immunoprecipitation (IP) experiments.
- Published
- 2014
28. Fluorescent Probes for Single-Step Detection and Proteomic Profiling of Histone Deacetylases.
- Author
-
Yusheng Xie, Jingyan Ge, Haipeng Lei, Bo Peng, Huatang Zhang, Danyang Wang, Sijun Pan, Ganchao Chen, Lanfang Chen, Yi Wang, Quan Hao, Yao, Shao Q., and Hongyan Sun
- Published
- 2016
- Full Text
- View/download PDF
29. In Situ Proteome Profiling and Bioimaging Applications of Small-Molecule Affinity-Based Probes Derived From DOT1L Inhibitors.
- Author
-
Biwei Zhu, Hailong Zhang, Sijun Pan, Chenyu Wang, Jingyan Ge, Jun-Seok Lee, and Shao Q. Yao
- Subjects
PROTEOMICS ,SMALL molecules ,CHEMICAL affinity ,MOLECULAR probes ,METHYLTRANSFERASES ,HISTONES - Abstract
DOT1L is the sole protein methyltransferase that methylates histone H3 on lysine 79 (H3K79), and is a promising drug target against cancers. Small-molecule inhibitors of DOT1L such as FED1 are potential anti-cancer agents and useful tools to investigate the biological roles of DOT1L in human diseases. FED1 showed excellent in vitro inhibitory activity against DOT1L, but its cellular effect was relatively poor. In this study, we designed and synthesized photo-reactive and "clickable" affinity-based probes (AfBPs), P1 and P2, which were cell-permeable and structural mimics of FED1. The binding and inhibitory effects of these two probes against DOT1L protein were extensively investigated in vitro and in live mammalian cells (in situ). The cellular uptake and sub-cellular localization properties of the probes were subsequently studied in live-cell imaging experiments, and our results revealed that, whereas both P1 and P2 readily entered mammalian cells, most of them were not able to reach the cell nucleus where functional DOT1L resides. This offers a plausible explanation for the poor cellular activity of FED1. Finally with P1/P2, large-scale cell-based proteome profiling, followed by quantitative LC-MS/MS, was carried out to identify potential cellular off-targets of FED1. Amongst the more than 100 candidate off-targets identified, NOP2 (a putative ribosomal RNA methyltransferase) was further confirmed to be likely a genuine off-target of FED1 by preliminary validation experiments including pull-down/Western blotting (PD/WB) and cellular thermal shift assay (CETSA). [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
30. "Minimalist" Cyclopropene-Containing Photo-Cross-Linkers Suitable for Live-Cell Imaging and Affinity-Based Protein Labeling.
- Author
-
Zhengqiu Li, Danyang Wang, Lin Li, Sijun Pan, Zhenkun Na, Tan, Chelsea Y. J., and Shao Q. Yao
- Published
- 2014
- Full Text
- View/download PDF
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