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Semi-synthesis of disulfide-linked branched tri-ubiquitin mimics

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Science China Chemistry 2018年第4期61卷 412-417页

作者： Yanyan Si Lujun Liang Shan Tang Yunkun Qi Yong Huang Lei Liu Key laboratory of chemical genomics School of Chemical Biology and BiotechnologyPeking UniversityShenzhen Graduate School Department of Chemistry Tsinghua University

Ubiquitin(Ub) chain isopeptide bond mimics are useful molecules for biochemical and biophysical studies. Herein, we report the semi-synthesis of the disulfide-linked K11/K48-branched tri-Ub(Ub_3^(11/48)(S-S)), the first example of an isopeptide mimic for the branched Ub chains,which have recently emerged as an interesting category of Ub modifications. Our strategy comprised the El-dependent synthesis of the Ub conjugate of aminoethanethiol, followed by disulfide formation with Ub(K11 C, K48 C). The structure of the synthetic isopeptide bond mimics was verified by the crystal structure of Ub_3^(11/48)(S-S). Deubiquitination and pulldown assays indicated that the synthetic Ub_3^(11/48)(S-S) could be hydrolyzed by linkage-specific deubiquitinases(K11-specific Cezanne and K48-specific OTUB1), and recognized by proteasomal ubiquitin receptor S5 a.

关键词： ubiquitin chain isopeptide bond mimics disulfide-directed strategy branched Ub chains crystal structure

Applications of genetic code expansion technology in eukaryotes

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Protein & Cell 2024年第5期15卷 331-363页

作者： Qiao-ru Guo Yu J.Cao State Key laboratory of chemical Oncogenomic Guangdong Provincial Key Laboratory of Chemical GenomicsPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China

Unnatural amino acids(UAAs)have gained significant attention in protein engineering and drug development owing to their ability to introduce new chemical functionalities to *** eukaryotes,genetic code expansion(GCE)enables the incorporation of UAAs and facilitates posttranscriptional modification(PTM),which is not feasible in prokaryotic *** is also a powerful tool for cell or animal imaging,the monitoring of protein interactions in target cells,drug development,and switch ***,there is keen interest in utilizing GCE in eukaryotic *** review provides an overview of the application of GCE in eukaryotic systems and discusses current challenges that need to be addressed.

关键词： genetic code expansion unnatural amino acid eukaryotes basic research therapeutic applications

Catalytic enantioselective domino alkenylation-alkynylation of alkenes: stereoselective synthesis of 5–7 membered azacycles and carbocycles

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Science China Chemistry 2023年第6期66卷 1701-1706页

作者： Zhaoming Ma Lantian Sun Jianrong Steve Zhou State Key laboratory of chemical Oncogenomics Guangdong Provincial Key Laboratory of Chemical GenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China Department of Chemistry Hong Kong Baptist UniversityHong KongChina

Enantioselective domino alkenylation-alkynylation of olefins is achieved for the first time,using terminal alkynes directly as *** new reaction enables facile construction of azacycles carrying quaternary stereocenters,including 5–7 membered pyrrolidines,piperidines and ***,alkynyl groups in azacyclic products provide a useful handle for derivatization that formed both fused and bridged azabicycles.

关键词： membered cycles synthesis

Structural Insight into the Binding of Hypoxanthine with Purine Nucleoside Phosphorylase from Streptococcus mutants

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Chinese Journal of Structural Chemistry 2011年第1期30卷 43-50页

作者：侯巧明杨娜刘祥王宏飞李兰芬苏晓东 laboratory of chemical genomics School of Chemical Biology and BiotechnologyShenzhen Graduate School of Peking University National laboratory of Protein Engineering and Plant Genetic Engineering College of Life SciencesPeking University

Purine nucleoside phosphorylase is a key enzyme in the purine-salvage pathway and an attractive target for drug design. The crystal structure of Streptococcus mutants purine nucleoside phosphorylase（Smu PNP） has been solved by molecular replacement at 1.80  resolution and refined to R factors of 19.9%/23.7%（Rcryst/Rfree） . Sequence alignment and structural comparison show that Smu PNP has more similarity with PNPs isolated from human and malarial sources than the bacterial PNPs. The structure complexed with hypoxanthine（HPA） and sulfate ion was solved at 2.24A resolution and refined to R factors of 21.6%/24.1%（Rcryst/Rfree） . It is interesting to note that the resulting electron density indicated the product,HPA,presents in the active site although inosine was included in the crystallization mixture with Smu PNP. Asn233 and Glu191 are the important residues for ligand binding and recognition. Comparison with PNPs from different species gives detailed information about binding of small molecules on the active site,which is important for the studies of enzymatic mechanism and rational design of specific inhibitors for PNPs.

关键词： Streptococcus mutants purine nucleoside phosphorylase crystal structure

Optimized Target-AID system efficiently induces single base changes in zebrafish

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Journal of Genetics and genomics 2018年第4期45卷 215-217页

作者： Xiaochan Lu Yunxing Liu Guanrong Yan Song Li Wei Qin Shuo Lin State Key laboratory of chemical Oncogenomics Key Laboratory of Chemical Genomics Peking University Shenzhen Graduate School Department of Molecular Cell and Development Biology University of CaliforniaLos Angeles

CRISPR-Cas system has been widely adapted as a platform for genome editing in various eukaryotic organisms, including zebrafish（Cong et al., 2013; Hwang et al., 2013）. One of the important applications of CRISPR-Cas... 详细信息

关键词： AID Optimized Target-AID system efficiently induces single base changes in zebrafish Target

chemical synthesis of histone H2A with methylation at Gln104

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Science China Chemistry 2017年第5期60卷 621-627页

作者： Qiaoqiao He Jiabin Li Yunkun Qi Zhipeng Wang Yong Huang Lei Liu Key laboratory of chemical genomics School of Chemical Biology and Biotechnology Peking University Shenzhen Graduate School School of Life Sciences University of Science and Technology of China Department of Chemistry Tsinghua University

Histone H2A methylation at Glnl04 （H2AQ104Me） is a new type of histone post-translational modification （PTM） discovered recently. This modification has been found to have significant influence on gene transcription. However, the structural and fimctional consequence of glutamine methylation on nucleosome remains to be further elucidated. Obtaining of histones with site-specific methylation at glutamine residues might facilitate the studies towards a better understanding of this new PTM. In the present work, total chemical synthesis of H2AQ 104Me was carried out through use of the hydrazide-based native chemical ligation. Synthetic histone H2AQ104Me could be successfully incorporated into nucleosomes in vitro and showed a negative influence on the nucleosome stability.

关键词： protein chemical synthesis glutamine methylation histone H2A thermal stability

Theoretical prediction on the reactivity of the Co-mediated intramolecular Pauson-Khand reaction for constructing bicyclo-skeletons in natural products

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Chinese chemical Letters 2019年第4期30卷 889-894页

作者： Lei Zhu Zheyuan Wang Song Liu Tao Zhang Zhen Yang Ruopeng Bai Yu Lan School of Chemistry and chemical Engineering Chongqing Key Laboratory of Theoretical and Computational Chemistry Chongqing University laboratory of chemical genomics School of Chemical Biology and Biotechnology Peking University Shenzhen Graduate School College of Chemistry and Molecular Engineering Zhengzhou University

The Co_2(CO)_8-mediated intramolecular Pauson-Khand reaction is an efficient approach for constructing polycyclic skeletons. Recently, some of us reported a series of this type reactions involving stericallyhindered enynes for synthesizing natural products with reasonable reaction rates and yields. However,the reason for the high reactivity of the reaction remains unclear. We employed density functional theory calculations to clarify the mechanism and reactivity for this reaction. In contrast with chain olefin reactants, CO insertion is considered to be the rate-determining step for the overall Pauson-Khand reaction of cyclooctene derivatives. The reduced activation free energy for the alkene insertion step is attributed to: i) the electron-withdrawing group in close proximity to the C—C triple bond enhancing the reactivity of the alkyne moiety; ii) lower steric hindrance during alkene insertion when using the cyclooctene derivative. The effect of the substituent on the Co_2(CO)_8-mediated intramolecular PausonKhand reaction was then investigated. Internal alkenes exhibit lower reactivity than terminal alkenes because of the steric hindrance introduced by the substituted group. The cis internal alkene exhibits higher reactivity than the trans internal alkene. An ester group in close proximity to the C—C triple bond significantly enhances the reactivity.

关键词： Pauson-Khand reaction Bicyclo-skeletons DFT calculations Mechanism Reactivity

Oxidative lactonization of C(sp^(3))–H bond in methyl aromatic alcohols enabled by proton-coupled electron transfer

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Science China Chemistry 2022年第8期65卷 1526-1531页

作者： Shanyi Chen Qihong Lai Chao Liu Hui Liu Mingqiang Huang Shunyou Cai Fujian Provincial Key laboratory of Modern Analytical Science and Separation Technology School of ChemistryChemical Engineering and EnvironmentMinnan Normal UniversityZhangzhou 363000China Guangdong Provincial Key laboratory of chemical genomics School of Chemical Biology and BiotechnologyShenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Direct functionalization of inert C(sp^(3))–H bonds in pharmaceutically significant compounds is very important in modern synthetic organic *** this article,we disclose a practical and efficient method for the oxidative lactonization of benzylic C(sp^(3))–H bonds enabled by the synergistic interactions of organic dye-type rose bengal,n-Bu_(4)N∙Br,O_(2) and Na_(2)HPO_(4) under visible light *** reaction does not require transition metal catalysts or strong oxidants.A range of structurally diverse phthalides has been synthesized with excellent selectivity and high functional group *** late-stage application of this reaction to the preparation of structurally complex phthalides demonstrates its synthetic utility.

关键词： photoredox catalyst metal free singlet oxygen bromine radical dehydrogenated lactonization

Synthesis and structure determination of pyrazine-containing macrocyclic polyazomethines

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Chinese chemical Letters 2010年第10期21卷 1263-1266页

作者： Liang Chun Wu Long Qing Liu Hai Shan Jin Ming Liang Ma Xiao Li Zhao Ke Wen Division of Supramolecular Chemistry and Medicinal Chemistry Key Laboratory of Brain Functional Genomics MOE and Shanghai Key Laboratory of Brain Functional Genomics East China Normal University Shanghai 200062 China Shanghai Key laboratory of Green Chemistry and chemical Processes and Department of Chemistry East China Normal University Shanghai 200062 China

Two pyrazine-containing macrocyclic polyazomethines 2 and 3 were synthesized by direct [2 ＋ 2] and [3 ＋ 3] condensation reactions between 2,21-[pyrazine-2,3-diylbis（oxy）]dibenzaldehyde （1） and hydrazine. Both 2 ... 详细信息

关键词： Azomethine Macrocycles Schiff base Pyrazine