Recently, a research group led by Prof. LI Guohui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. CHEN Jianfeng's group from Shanghai Institute of Biochemistry and Cell Biology of CAS, revealed the regulation mechanism of integrin α4β7 mediated human immunodeficiency virus 1 (HIV-1) infection.
　　This study was published in Signal Transduction and Targeted Therapy on July 16.
　　Experiment setup for measuring FRET efficiency between integrin α4β7 βI domain and the plasma membrane (top left); Adhesion of integrin α4β7 T cells to the immobilized gp120 with different chemokine stimulations (top right); Molecular details underlying the conformational rearrangements integrin α4β7 headpiece, which direct correlations with integrin activation and gp120 binding (bottom) (Image by ZHANG Yuebin and LI Guohui)
　　Integrin α4β7, an important cell surface adhesion molecule, is responsible for mediating lymphocytes from blood circulation into the intestine and central nervous system. The abnormality of its function is closely related to human autoimmune diseases.
　　Previous studies have shown that intestinal homing CD4+ T cells expressing integrin α4β7 are the early targets of HIV-1 virus infection, which plays an important role in the pathogenesis of HIV-1 infection.
　　The binding between the envelope protein gp120 located on the surface of the HIV-1 virus and the receptors on the surface of CD4+ T cells is a key step for HIV-1 to infect T cells.
　　In this study, the researchers investigated the interaction between integrin α4β7 and gp120. They found that specific intestinal chemokines could stimulate integrin α4β7 in a relatively stretched condition, leading to a highly activated conformation state, and it enabled integrin α4β7 to bind the HIV-1 envelope protein gp120. While, the inactive integrin α4β7 exhibited no binding ability with HIV-1 envelope protein gp120.
　　Moreover, they indicated that the interactions between the metal ion-dependent adhesion site (MIDAS) in the integrin β7 subunit and the highly conserved tripeptide LDI in the HIV-1 envelope protein gp120 were the key site for integrin α4β7 mediated HIV-1 infection.
　　In addition, they also found that the interactions between integrin α4β7 and HIV-1 envelope protein gp120 might activate multiple intracellular signaling pathways, which further regulated HIV-1 virus replication and T cell function.
　　"This study would provide new strategies and ideas for the prevention and treatment of HIV-1 infection and the screening of related drugs," said Prof. LI.
　　The research was supported by the National Natural Science Foundation of China. (Text by ZHANG Yuebin and LI Guohui)

　　A research group led by Prof. PIAO Hailong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) identified hepatocellular carcinoma (HCC) subtypes with distinctive metabolic phenotypes through bioinformatics and machine learning methods, and elucidated the potential mechanisms based on a metabolite-protein interaction network and multi-omics data.
　　The study, published in Advanced Science on July 11, provides insights guiding precise personalized HCC medicine.
　　Metabolic reprogramming, which can promote rapid cell proliferation by regulating energy and nutrient metabolism, is considered to be one hallmark of cancer. It can impact other biological processes through complex metabolite-protein interactions.
　　The researchers utilized complex network and machine learning methods to analyze multi-omics data and the metabolite-protein interaction network to identify hepatocellular carcinoma subtypes with significant differences in prognosis.
　　Identification and characterization of robust hepatocellular carcinoma prognostic subtypes based on an integrative metabolite-protein interaction network (Image by CHEN Di)
　　They identified a metabolic HCC subtype with poor prognosis, which is strongly correlated with hypoxia, hypermethylation of metabolic enzymes, down-regulation of various metabolic pathways, and accumulation of multiple fatty acids. In addition, many immune-related pathways were significantly up-regulated in this poor prognosis subtype.
　　Based on further analyses of metabolite-protein interactions, the researchers predicted multiple interactions between unsaturated fatty acid and immunoregulatory proteins, suggesting that unsaturated fatty acid accumulation may be one potential cause of immune pathway up-regulation. (Text by CHEN DI)

Pichia pastoris (syn. Komagataella phaffii), a model methylotrophic yeast, can easily achieve high density fermentation, and thus is considered as a promising chassis cell for efficient methanol biotransformation. However, inefficient gene editing and lack of synthetic biology tools hinder its metabolic engineering toward industrial application.Recently, a research group led by Prof. ZHOU Yongjin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences established an efficient genetic engineering platform in Pichia pastoris.This study was published in Nucleic Acids Research on July 1.The researchers developed novel genetic tools for precise genome editing in Pichia pastoris by enhancing homologous recombination (HR) rates and engineering the multiple intrusion-induced rearrangement (MIR) processes. The key gene RAD52, which played crucial role in HR repair in Pichia pastoris, was overexpressed for improving the efficiency of single gene editing to 90%.Furthermore, they increased the efficiency of multi-fragment recombination at one site by 13.5 times, and identified and characterized 46 neutral sites and 18 promoters for genome integration and gene expression.Finally, they developed a two-factorial regulation system for regulating fatty alcohol biosynthesis in Pichia pastoris from different carbon source.Establishing an efficient genetic engineering platform for metabolic engineering of Methylotrophic yeast Pichia pastoris (Image by CAI Peng)"This advanced gene editing systems can theoretically realize stable loading of more than 100 exogenous genes and precise regulation of gene expression in Pichia pastoris , which will provide convenience for the synthetic biology research of Pichia pastoris. It also provides insights for metabolic engineering of other unconventional yeast." said Prof. ZHOU.This study was supported by National Natural Science Foundation of China and Dalian Science and Technology Innovation Funding. (Text by CAI Peng)

　　Ultra-deep removal of H2S is important in petroleum refining, natural gas purification and coal chemical industry. However, the industrial catalysts for continuous H2S selective oxidation show poor activity and stability, especially on feed gas containing steam and impurity gas.
　　Recently, Assoc. Prof. LIU Yuefeng's group from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) fabricated monolithic nanocarbon composites for continuous removal of high concentration of H2S, presenting superior product selectivity and stability under high concentration of O2, CO2 and steam.
　　This work was published in ACS Catalysis on June 30.
　　The monolithic nanocarbon catalyst presents superior catalytic performance for H2S selective oxidation with improved sulfur selectivity and impurity tolerance (Image by XU Chi) 
　　Nanocarbon materials possess unique surface chemical properties and excellent catalytic performance, However, the overactive sites and the exothermic characteristics of the reaction can cause overoxidation of product into SOX.
　　The researchers achieved high selectivity of sulfur for the selective oxidation of H2S without losing conversion by phosphate-modified N-doped 3D mesoporous monolithic carbocatalysts (N-C/CNT), leading to a high sulfur formation rate.
　　The P-modified N-C/CNT monolith exhibited high stability even under severe reaction environments with CO2, O2, steam and SO2, indicating the promising potential for the practical application.
　　Combining advanced characterization methods (XPS, TPD), kinetic analysis and theoretical calculation, the researchers found that the interaction between the P group and pyridine site, which was the active center, could moderate the adsorption and activity of O2 on the active site, thus avoiding the occurrence of over oxidation and improving the selectivity of the product.
　　This work was supported by the National Natural Science Foundation of China, Liaoning Revitalization Talents Program, CAS Youth Innovation Promotion Association, and Talents Innovation Project of Dalian City. (Text by XU Chi)

　　Cesium lead halide perovskite CsPbX3 (X: Cl, Br, I) nanocrystals (NCs) with narrow photoluminescence (PL) emission band have been widely applied for light-emitting devices. However, their toxicity and poor stability triggered the development of lead-free metal halide perovskite NCs.
　　It is highly desirable to obtain tunable red/green/blue emission in display application. However, lead-free perovskite NCs generally exhibit broadband emission with poor color purity.
　　Recently, a research group led by Prof. HAN Keli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a phase transition strategy to design cesium manganese bromides NCs with a tunable red/green/blue emission and high color purity.
　　This study was published in Angewandte Chemie International Edition on June 20.
　　A unique phase transition strategy to engineer the emission color of lead-free cesium manganese bromides nanocrystals, which achieves a tunable red/green/blue emission with high color purity (Image by YANG Bin and KONG Qingkun) 
　　The researcher selectively synthesized of one dimensional (1D) CsMnBr3 NCs (red-color emission) and zero dimensional (0D) Cs3MnBr5 NCs (green-color emission) with pure phase. Such phase transition could be triggered by isopropanol: from 1D CsMnBr3 NCs to 0D Cs3MnBr5 NCs.
　　Furthermore, in a humid environment both 1D CsMnBr3 NCs and 0D Cs3MnBr5 NCs could be transformed into 0D Cs2MnBr4·2H2O NCs (blue-color emission). Cs2MnBr4·2H2O NCs could inversely transform into the mixture of CsMnBr3 and Cs3MnBr5 phase during the thermal annealing dehydration step.
　　This work highlights the tunable optical properties in single component NCs via phase engineering and provides a new avenue for future endeavors in light-emitting devices.
　　"Moreover, this proposed strategy is important in obtaining the stability of NCs against destruction by air and water and provides a unique approach for the application of this material in anti-counterfeiting," said Prof. HAN.
　　This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Scientific Instrument Developing Project of CAS, Liaoning Revitalization Talents Program, and the Dalian City Foundation for Science and Technology Innovation. (Text by YANG Bin and KONG Qingkun)

　　Metal-free halide perovskites are novel candidates for ferroelectrics and X-ray detection. However, the molecular self-assembly of these perovskites and its influence remain unexplored.
　　Recently, a research group led by Prof. LIU Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) fabricated halide-modulated self-assembly of metal-free perovskite single crystals for bio-friendly X-ray detection.
　　This study was published in Matter on June 14.
　　Metal-free perovskite series, DABCO-NH4X3 (X = Cl, Br, I), exhibit a remarkable variety of perovskite-type structures through halide modulation, therefore their single crystals grown at the same condition show different crystal morphology (Image by DUAN Lianjie)
　　Molecular self-assembly plays a critical role in crystal engineering for the design and fabrication of novel metal-free perovskite compounds.
　　After preparing DABCO-NH4X3 (X = Cl, Br, I) single crystals, the researcher investigated halide-modulated molecular assembly via hydrogen bonding in metal-free perovskites and its influence on their crystal packing, band nature, mechanical and electrical properties, as well as final optoelectronic performance.
　　They found that the crystal DABCO-NH4I3 with superior in-plane charge transport and lower charge effective mass exhibited higher carrier mobility. Therefore, it presented better X-ray detection sensitivity, reaching 567 μC Gyair-1 cm–2. Meanwhile, they demonstrated the feasibility of X-ray imaging had a well-defined 'heart' image.
　　A variety of non-metallic and organic groups readily were available for the A, B and X in crystal DABCO-NH4I3, resulting in fine-tuned properties and free of associated toxicity.
　　"This work benefited the understanding of molecular self-assembly behavior and was intended to inspire activities to study an assortment of novel ABX3 perovskite materials for potential biological and therapeutic applications," said Prof. LIU.
　　This work was supported by the National Key Research and Development Program of China, the Key Program project of the National Natural Science Foundation of China, the National Natural Science Foundation of China, the 111 Project. (Text by DUAN Lianjie)