RSC Chemical Biology最新文献

{"title":"Redox-neutral, metal-free tryptophan labeling of polypeptides in hexafluoroisopropanol (HFIP)†","authors":"Mohammad Nuruzzaman, Brandon M. Colella, Zeinab M. Nizam, Isaac JiHoon Cho, Julia Zagorski and Jun Ohata","doi":"10.1039/D4CB00142G","DOIUrl":"10.1039/D4CB00142G","url":null,"abstract":"<p >Despite the unmet needs for chemical tools to study biological roles of tryptophan in living systems, there has been a lack of chemical modification methods for tryptophan residues that can be used in cellular environments. Driven by a preliminary computational study of our previous research, this work experimentally examined our hypotheses to translate the metal-catalyzed tryptophan modification method in hexafluoroisopropanol (HFIP) into a metal-free process. While one of the hypotheses merely confirmed the superiority of the thiophene–ethanol reagent developed in the previous report, the second hypothesis resulted in the identification of a trifluoroborate salt and an acidic ionic liquid as alternatives for the catalysis. Labeling of lysates of a human cell line was achieved with the acidic ionic liquid catalyst, where negative impacts of the tryptophan labeling and HFIP medium on the cellular samples were apparently insignificant. Because the labeling process does not require any redox mediators and is a formal redox-neutral reaction, the metal-free approach would be of use for tryptophan biology research potentially related to their various redox roles.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11368038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142134131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding the repertoire of GalNAc analogues for cell-specific bioorthogonal tagging of glycoproteins†","authors":"Abdul Zafar, Sandhya Sridhar, Ganka Bineva-Todd, Anna Cioce, Nadia Abdulla, Vincent Chang, Stacy A. Malaker, David S. Hewings and Benjamin Schumann","doi":"10.1039/D4CB00093E","DOIUrl":"10.1039/D4CB00093E","url":null,"abstract":"<p >Glycosylation is a ubiquitous modification of proteins, necessitating approaches for its visualization and characterization. Bioorthogonally tagged monosaccharides have been instrumental to this end, offering a chemical view into the cell biology of glycans. Understanding the use of such monosaccharides by cellular biosynthetic pathways has expanded their applicability in cell biology, for instance through the strategy named Bio-Orthogonal Cell-specific TAgging of Glycoproteins (BOCTAG). Here, we show that the cellular use of two azide-tagged analogues of the monosaccharide <em>N</em>-acetylgalactosamine (GalNAzMe and GalNPrAz) can be promoted through expression of two biosynthetic enzymes. More precisely, cellular expression of the bacterial kinase NahK and the engineered human pyrophosphorylase AGX1<small>^F383A</small> led to biosynthesis of the corresponding activated nucleotide-sugars and subsequent bioorthogonal tagging of the cellular glycoproteome. We explore the use of both sugars for BOCTAG, demonstrating the visualization of cell surface glycosylation tagged with GalNPrAz in a specific cell line in a co-culture system. Our work adds to the toolbox of glycoprotein analysis in biomedicine.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11369666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142141329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A refactored biosynthetic pathway for the production of glycosylated microbial sunscreens†","authors":"Sıla Arsın, Maija Pollari, Endrews Delbaje, Jouni Jokela, Matti Wahlsten, Perttu Permi and David Fewer","doi":"10.1039/D4CB00128A","DOIUrl":"10.1039/D4CB00128A","url":null,"abstract":"<p >Mycosporine-like amino acids (MAAs) are a family of water-soluble and colorless secondary metabolites, with high extinction coefficients, that function as microbial sunscreens. MAAs share a cyclohexinimine chromophore that is diversified through amino acid substitutions and attachment of sugar moieties. The genetic and enzymatic bases for the chemical diversity of MAAs remain largely unexplored. Here we report a series of structurally distinct MAAs and evidence for an unusual branched biosynthetic pathway from a cyanobacterium isolated from lake sediment. We used a combination of high-resolution liquid chromatography-mass spectrometry (HR-LCMS) analysis and nuclear magnetic resonance (NMR) spectroscopy to identify diglycosylated-palythine-Ser (C<small>₂₂</small>H<small>₃₆</small>N<small>₂</small>O<small>₁₅</small>) as the dominant chemical variant in a series of MAAs from <em>Nostoc</em> sp. UHCC 0302 that contained either Ser or Thr. We obtained a complete 9.9 Mb genome sequence to gain insights into the genetic basis for the biosynthesis of these structurally distinct MAAs. We identified MAA biosynthetic genes encoded at two locations on the circular chromosome. Surprisingly, direct pathway cloning and heterologous expression of the complete <em>mysABCJ</em><small>_<em>1</em></small><em>D</em><small>_<em>1</em></small><em>G</em><small>_<em>1</em></small><em>H</em> biosynthetic gene cluster in <em>Escherichia coli</em> (<em>E. coli</em>) led to the production of 450 Da monoglycosylated-palythine-Thr (C<small>₁₈</small>H<small>₃₀</small>N<small>₂</small>O<small>₁₁</small>). We reconstructed combinations of the two distant biosynthetic gene clusters in refactored synthetic pathways and expressed them in the heterologous host. These results demonstrated that the MysD<small>₁</small> and MysD<small>₂</small> enzymes displayed a preference for Thr and Ser, respectively. Furthermore, one of the four glycosyltransferases identified, MysG<small>₁</small>, was active in <em>E. coli</em> and catalysed the attachment of a hexose moiety to the palythine-Thr intermediate. Together these results provide the first insights into the enzymatic basis for glycosylation of MAAs and demonstrates how paralogous copies of the MysD enzymes allow the simultaneous biosynthesis of specific chemical variants to increase the structural variation in this family of microbial sunscreens.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11378024/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142156233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biosynthesis of the corallorazines, a widespread class of antibiotic cyclic lipodipeptides†","authors":"Teresa M. Dreckmann, Lisa Fritz, Christian F. Kaiser, Sarah M. Bouhired, Daniel A. Wirtz, Marvin Rausch, Anna Müller, Tanja Schneider, Gabriele M. König and Max Crüsemann","doi":"10.1039/D4CB00157E","DOIUrl":"10.1039/D4CB00157E","url":null,"abstract":"<p >Corallorazines are cyclic lipodipeptide natural products produced by the myxobacterium <em>Corallococcus coralloides</em> B035. To decipher the basis of corallorazine biosynthesis, the corallorazine nonribosomal peptide synthetase (NRPS) biosynthetic gene cluster <em>crz</em> was identified and analyzed in detail. Here, we present a model of corallorazine biosynthesis, supported by bioinformatic analyses and <em>in vitro</em> investigations on the bimodular NRPS synthesizing the corallorazine core. Corallorazine biosynthesis shows several distinct features, such as the presence of a dehydrating condensation domain, and a unique split adenylation domain on two open reading frames. Using an alternative fatty acyl starter unit, the first steps of corallorazine biosynthesis were characterized <em>in vitro</em>, supporting our biosynthetic model. The dehydrating condensation domain was bioinformatically analyzed in detail and compared to other modifying C domains, revealing unreported specific sequence motives for this domain subfamily. Using global bioinformatics analyses, we show that the <em>crz</em> gene cluster family is widespread among bacteria and encodes notable chemical diversity. Corallorazine A displays moderate antimicrobial activity against selected Gram-positive and Gram-negative bacteria. Mode of action studies comprising whole cell analysis and <em>in vitro</em> test systems revealed that corallorazine A inhibits bacterial transcription by targeting the DNA-dependent RNA polymerase.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11342130/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142056870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altering glycopeptide antibiotic biosynthesis through mutasynthesis allows incorporation of fluorinated phenylglycine residues†","authors":"Irina Voitsekhovskaia, Y. T. Candace Ho, Christoph Klatt, Anna Müller, Daniel L. Machell, Yi Jiun Tan, Maxine Triesman, Mara Bingel, Ralf B. Schittenhelm, Julien Tailhades, Andreas Kulik, Martin E. Maier, Gottfried Otting, Wolfgang Wohlleben, Tanja Schneider, Max Cryle and Evi Stegmann","doi":"10.1039/D4CB00140K","DOIUrl":"10.1039/D4CB00140K","url":null,"abstract":"<p >Glycopeptide antibiotics (GPAs) are peptide natural products used as last resort treatments for antibiotic resistant bacterial infections. They are produced by the sequential activities of a linear nonribosomal peptide synthetase (NRPS), which assembles the heptapeptide core of GPAs, and cytochrome P450 (Oxy) enzymes, which perform a cascade of cyclisation reactions. The GPAs contain proteinogenic and nonproteinogenic amino acids, including phenylglycine residues such as 4-hydroxyphenylglycine (Hpg). The ability to incorporate non-proteinogenic amino acids in such peptides is a distinctive feature of the modular architecture of NRPSs, with each module selecting and incorporating a desired amino acid. Here, we have exploited this ability to produce and characterise GPA derivatives containing fluorinated phenylglycine (F-Phg) residues through a combination of mutasynthesis, biochemical, structural and bioactivity assays. Our data indicate that the incorporation of F-Phg residues is limited by poor acceptance by the NRPS machinery, and that the phenol moiety normally present on Hpg residues is essential to ensure both acceptance by the NRPS and the sequential cyclisation activity of Oxy enzymes. The principles learnt here may prove useful for the future production of GPA derivatives with more favourable properties through mixed feeding mutasynthesis approaches.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11376024/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142156234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superoxide-responsive quinone methide precursors (QMP-SOs) to study superoxide biology by proximity labeling and chemoproteomics†","authors":"Hinyuk Lai and Clive Yik-Sham Chung","doi":"10.1039/D4CB00111G","DOIUrl":"10.1039/D4CB00111G","url":null,"abstract":"<p >Superoxide is a reactive oxygen species (ROS) with complex roles in biological systems. It can contribute to the development of serious diseases, from aging to cancers and neurodegenerative disorders. However, it can also serve as a signaling molecule for important life processes. Monitoring superoxide levels and identifying proteins regulated by superoxide are crucial to enhancing our understanding of this growing field of redox biology and signaling. Given the high reactivity and very short lifetime of superoxide compared to other ROS in biological systems, proteins redox-modified by superoxide should be in close proximity to where superoxide is generated endogenously, <em>i.e.</em> superoxide hotspots. This inspires us to develop superoxide-specific quinone methide-based precursors, QMP-SOs, for proximity labeling of proteins within/near superoxide hotspots to image superoxide and profile proteins associated with superoxide biology by chemoproteomics. QMP-SOs specifically react with superoxide to generate an electrophilic quinone methide intermediate, which subsequently reacts with nucleophilic amino acids to induce a covalent tag on proteins, as revealed by liquid chromatography-mass spectrometry (LC-MS) and shotgun MS experiments. The alkyne handle on the covalent tag enables installation of fluorophores onto the tagged proteins for fluorescence imaging of superoxide in cells under oxidative stress. By establishing a chemoproteomics platform, QMP-SO-TMT, we identify DJ-1 and DLDH as proteins associated with superoxide biology in liver cancer cells treated with menadione. This work should provide insights into the crosstalk between essential cellular events and superoxide redox biology, as well as the design principles of quinone methide-based probes to study redox biology through proximity labeling and chemoproteomics.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cb/d4cb00111g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early-stage biosynthesis of phenalinolactone diterpenoids involves sequential prenylation, epoxidation, and cyclization†","authors":"Tyler A. Alsup, Zining Li, Caitlin A. McCadden, Annika Jagels, Diana P. Łomowska-Keehner, Erin M. Marshall, Liao-Bin Dong, Sandra Loesgen and Jeffrey D. Rudolf","doi":"10.1039/D4CB00138A","DOIUrl":"10.1039/D4CB00138A","url":null,"abstract":"<p >The chemical logic associated with assembly of many bacterial terpenoids remains poorly understood. We focused our efforts on the early-stage biosynthesis of the phenalinolactone diterpenoids, demonstrating that the <em>anti/anti/syn</em>-perhydrophenanthrene core is constructed by sequential prenylation, epoxidation, and cyclization. The functions and timing of PlaT1–PlaT3 were assigned by comprehensive heterologous reconstitution. We illustrated that the UbiA prenyltransferase PlaT3 acts on geranylgeranyl diphosphate (GGPP) in the first step of phenalinolactone biosynthesis, prior to epoxidation by the flavin-dependent monooxygenase PlaT1 and cyclization by the type II terpene cyclase PlaT2. Finally, we isolated eight new-to-nature terpenoids, expanding the scope of the bacterial terpenome. The biosynthetic strategy employed in the assembly of the phenalinolactone core, with cyclization occurring after prenylation, is rare in bacteria and resembles fungal meroterpenoid biosynthesis. The findings presented here set the stage for future discovery, engineering, and enzymology efforts in bacterial meroterpenoids.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cb/d4cb00138a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adrenodoxin allosterically alters human cytochrome P450 11B enzymes to accelerate substrate binding and decelerate release†","authors":"Cara L. Loomis, Sang-Choul Im and Emily E. Scott","doi":"10.1039/D4CB00015C","DOIUrl":"10.1039/D4CB00015C","url":null,"abstract":"<p >Two human mitochondrial membrane CYP11B enzymes play a pivotal role in steroidogenesis. CYP11B1 generates the major glucocorticoid cortisol, while CYP11B2 catalysis yields the primary mineralocorticoid aldosterone. Catalysis by both requires electron delivery by a soluble iron–sulfur adrenodoxin redox partner. However recent studies have shown that adrenodoxin/CYP11B interaction alone allosterically increases substrate and inhibitor affinity as exhibited by decreased dissociation constant (<em>K</em><small>_d</small>) values. The current study moves beyond such equilibrium studies, by defining adrenodoxin effects on the rates of P450 ligand binding and release separately. Stopped-flow data clearly demonstrate that adrenodoxin interaction with the P450 proximal surfaces increases ligand binding in both P450 CYP11B active sites by increasing the on rate constant and decreasing the off rate constant. As substrate entry and exit from the sequestered P450 active site requires conformational changes on the distal side of the P450 enzyme, a likely explanation is that adrenodoxin binding allosterically modulates CYP11B conformational changes. The 93% identical CYP11B enzymes can bind and hydroxylate each other's native substrates differing only by a hydroxyl. However, CYP11B1 exhibits monophasic substrate binding and CYP11B2 biphasic substrate binding, even when the substrates are swapped. This indicates that small differences in amino acid sequence between human CYP11B1 and CYP11B2 enzymes are more functionally important in ligand binding and could suggest avenues for more selective inhibition of these drug targets. Both protein/protein interactions and protein/substrate interactions are most likely to act by modulating CYP11B conformational dynamics.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cb/d4cb00015c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel strategy for activating gene expression through triplex DNA formation targeting epigenetically suppressed genes†","authors":"Ryotaro Notomi, Shigeki Sasaki and Yosuke Taniguchi","doi":"10.1039/D4CB00134F","DOIUrl":"10.1039/D4CB00134F","url":null,"abstract":"<p >Triplex DNA formation is a useful genomic targeting tool that is expected to have a wide range of applications, including the antigene method; however, there are fundamental limitations in its forming sequence. We recently extended the triplex DNA-forming sequence to methylated DNA sequences containing <small>^5m</small>CG base pairs by developing guanidino-dN, which is capable of recognizing a <small>^5m</small>CG base pair with high affinity. We herein investigated the effect of triplex DNA formation using TFOs with guanidino-dN on methylated DNA sequences at the promoter of the RASSF1A gene, whose expression is epigenetically suppressed by DNA methylation in MCF-7 cells, on gene expression. Interestingly, triplex DNA formation increased the expression of the RASSF1A gene at the transcript and protein levels. Furthermore, RASSF1A-activated MCF-7 cells exhibited cell growth suppressing activity. Changes in the expression of various genes associated with the promotion of apoptosis and breast cancer survival accompanied the activation of RASSF1A in cells exhibited antiproliferative activity. These results suggest the potential of increases in gene expression through triplex DNA formation as a new genomic targeting tool.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cb/d4cb00134f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peptide dendrimers transfecting CRISPR/Cas9 plasmid DNA: optimization and mechanism†","authors":"Susanna Zamolo, Elena Zakharova, Lise Boursinhac, Florian Hollfelder, Tamis Darbre and Jean-Louis Reymond","doi":"10.1039/D4CB00116H","DOIUrl":"10.1039/D4CB00116H","url":null,"abstract":"<p >Gene editing by CRISPR/Cas9 offers great therapeutic opportunities but requires delivering large plasmid DNA (pDNA) into cells, a task for which transfection reagents are better suited than viral vectors. Here we performed a structure–activity relationship study of <strong>Z22</strong>, a <small>D</small>-enantiomeric, arginine containing, lipidated peptide dendrimer developed for pDNA transfection of a CRISPR/Cas9 plasmid co-expressing GFP. While all dendrimer analogs tested bound pDNA strongly and internalized their cargo into cells, <small>D</small>-chirality proved essential for transfection by avoiding proteolysis of the dendrimer structure required for endosome escape and possibly crossing of the nuclear envelope. Furthermore, a cysteine residue at the core of <strong>Z22</strong> proved non-essential and was removed to yield the more active analog <strong>Z34</strong>. This dendrimer shows &gt;83% GFP transfection efficiency in HEK cells with no detrimental effect on cell viability and promotes functional CRISPR/Cas9 mediated gene editing. It is accessible by solid-phase peptide synthesis and therefore attractive for further development.</p>","PeriodicalId":40691,"journal":{"name":"RSC Chemical Biology","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cb/d4cb00116h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}