Protein expression and purification最新文献

{"title":"The N-terminal polypeptide of a new shell matrix protein hicraqin accelerates the rate of calcium carbonate deposition","authors":"Chenchen Liang ,&nbsp;Jiali Liu ,&nbsp;Guiling Wang ,&nbsp;Xiaojun Liu","doi":"10.1016/j.pep.2024.106642","DOIUrl":"10.1016/j.pep.2024.106642","url":null,"abstract":"<div><div>Matrix proteins play important roles in shell formation by regulating the assembly of organic matrix and minerals. Here, we obtained a new matrix protein (hicraqin) from <em>Hyriopsis cumingii</em>. The amino acid sequence of hicraqin contains multiple aggregated (Gly)n (n &gt; 2) residues, a feature unique to silk-like matrix proteins. <em>In situ</em> hybridization studies and tissue expression patterns demonstrated that hicraqin may be a prismatic layer matrix protein. In vitro experiments were performed using the peptide N-hicraqin (the N-terminal free sequence of hicraqin). In the <em>in vitro</em> crystallization of calcium carbonate, crystals resembling dumbbell, spindle, and lotus aragonite crystals were observed under scanning electron microscopy and confirmed as calcite by Raman spectroscopy. In the <em>in vitro</em> crystallization system of calcium carbonate with the addition of magnesium ions, aragonite plates were generated with 50 μg/mL of the peptide N-hicraqin. The fluorescent labeling analysis indicated that N-hicraqin was involved in the crystallization process. The crystallization rate experiment showed that the peptide N-hicraqin plays a role in promoting crystallization. Following the silencing of the hicraqin gene by RNA interference, its expression was reduced by about 61 %. There was incomplete formation of the organic framework outside the prismatic layer. Overall, the present study showed that N-hicraqin participates in the crystallization process and acts as a framework protein that influences the formation of the organic framework of the prismatic layer.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106642"},"PeriodicalIF":1.4,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142795062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent trends in production and potential applications of microbial amylases: A comprehensive review","authors":"Zain Ali ,&nbsp;Muhammad Abdullah ,&nbsp;Muhammad Talha Yasin ,&nbsp;Kinza Amanat ,&nbsp;Mohsin Sultan ,&nbsp;Aqdas Rahim ,&nbsp;Fatima Sarwar","doi":"10.1016/j.pep.2024.106640","DOIUrl":"10.1016/j.pep.2024.106640","url":null,"abstract":"<div><div>α-amylases are vital biocatalysts that constitute a billion-dollar industry with a substantial and enduring global demand. Amylases hydrolyze the α-1,4-glycosidic linkages in starch polymers to generate maltose and malto-oligosaccharides subunits. Amylases are key enzymes that have promising applications in various industrial processes ranging from pharmaceutical, pulp and paper, textile food industries to bioremediation and biofuel sectors. Microbial enzymes have been widely used in industrial applications owing to their ease of availability, cost-effectiveness and better stability at extreme temperatures and pH. α-amylases derived from distinct microbial origins exhibit diverse characteristics, which make them suitable for specific applications. The routine application of immobilized enzymes has become a standard practice in the production of numerous industrial products across the pharmaceutical, chemical, and food industries. This review details the structural makeup of microbial α-amylase to understand its thermodynamic characteristics, aiming to identify key areas that could be targeted for improving the thermostability, pH tolerance and catalytic activity of α-amylase through various immobilization techniques or specific enzyme engineering methods. Additionally, the review briefly explores the enzyme production strategies, potential sources of α-amylases, and use of cost-effective and sustainable raw materials for enzyme production to obtain α-amylases with unconventional applications in various industrial sectors. Major hurdles, challenges and future prospects involving microbial α-amylases has been briefly discussed by considering its diverse applications in industrial bioprocessing.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106640"},"PeriodicalIF":1.4,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient development of nanobody-based affinity chromatography for AAV8 purification","authors":"Guanghui Li ,&nbsp;Xiaofei Li ,&nbsp;Min Zhu,&nbsp;Peng Qiao,&nbsp;Weiwei Ji,&nbsp;Yuping Huang,&nbsp;Yicai Zhang,&nbsp;Xuee Li,&nbsp;Yakun Wan","doi":"10.1016/j.pep.2024.106638","DOIUrl":"10.1016/j.pep.2024.106638","url":null,"abstract":"<div><div>Adeno-associated virus serotype 8 (AAV8) is a highly effective vector for gene therapy. However, its purification remains challenging due to its low natural abundance and stringent purity requirements. This study aimed to develop an affinity chromatography resin utilizing nanobodies (Nbs) to enhance AAV8 purification efficiency. An AAV8-specific Nb library was constructed, leading to the identification of Nb9 as the most promising candidate based on its high binding affinity, stability and yield. Nb9 was expressed in <em>Pichia pastoris</em>, resulting in high yield and exceptional purity. Two types of agarose resins, Epoxy activated Bestarose 6B and PabPur SulfoLink Beads 4FF, were employed for Nb9 conjugation. Epoxy activated Bestarose 6B resin exhibited a significantly higher ligand density (9.12 mg/mL). Binding capacity assessments of the LQ01 resin demonstrated optimal performance at pH 7.0, with diminishing efficacy at lower and higher pH levels. Different NaCl concentrations influenced the binding efficiency, providing critical insights for refining purification conditions. Purification trials exhibited high specificity, purity and consistent VP protein ratio, as evidenced by SDS-PAGE analysis, confirming effective AAV8 capture and elution. Furthermore, the resin demonstrated robust performance across repeated cycles, retaining 71.9 % of its initial binding capacity after 20 uses and maintaining stability with only a 6 % reduction after 7 days at 37 °C. These findings highlight LQ01's potential for scalable and cost-effective AAV8 purification, while demonstrating the broader applicability of Nbs in affinity chromatography and biotechnological processes.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106638"},"PeriodicalIF":1.4,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142786777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expression of the Fusarium graminearum galactose oxidase GaoA in Saccharomyces cerevisiae","authors":"Lucas Yudai Nozaki,&nbsp;Nathalia Rodrigues Bulka,&nbsp;Karina Lima dos Reis,&nbsp;Damaris Batistão Martim,&nbsp;Fausto Fernandes de Castro,&nbsp;Ione Parra Barbosa-Tessmann","doi":"10.1016/j.pep.2024.106637","DOIUrl":"10.1016/j.pep.2024.106637","url":null,"abstract":"<div><div>Galactose oxidase, produced by fungi of the genus <em>Fusarium</em>, is an enzyme of great biotechnological importance. The <em>gaoA</em> gene has been recombinantly expressed in several hosts but has yet to be in <em>Saccharomyces cerevisiae</em>. This work aimed to express the <em>Fusarium graminearum</em> GaoA enzyme in <em>S. cerevisiae</em>. The full-length and the truncated <em>F. graminearum gaoA</em> gene were subcloned into a yeast expression vector. The GaoA enzyme expression level in <em>S. cerevisiae</em> was higher when the truncated gene, which codes for the mature form of the enzyme, was used. After purification of the expressed enzyme on a Sepharose® 6B column, the obtained yield of the pure and active enzyme was 16.7 mg/L. The purified protein showed a <em>K</em>_M of 9.8 mM, lower than that of the wild-type enzyme, and a <em>k</em>_cat/<em>K</em>_M of 2.9 × 10⁷ M⁻¹s⁻¹, higher than that of the wild-type enzyme. The expressed recombinant protein used several common substrates for galactose oxidase, such as galactose, raffinose, and 1,3-dihydroxyacetone dimer. In addition, it had increased activity on guar gum, lactose, and Arabic gum compared with the wild-type enzyme. The obtained enzyme's characteristics are compatible with the galactose oxidase biotechnological applications.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106637"},"PeriodicalIF":1.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142771648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The combined effect of the gene copy number and chaperone overexpression on the recombinant bovine chymosin production in Pichia pastoris, with mutant ADH2 promoter","authors":"Fatma Ersöz ,&nbsp;Mehmet İnan","doi":"10.1016/j.pep.2024.106636","DOIUrl":"10.1016/j.pep.2024.106636","url":null,"abstract":"<div><div>Chymosin is an enzyme used to coagulate milk, in the cheese industry. This study aimed to increase recombinant production of the chymosin in <em>Pichia pastoris</em> by determining the optimum copy number and overproduction of a Protein Disulfide Isomerase (<em>PpPDI)</em> chaperon protein. <em>Bos taurus</em> chymosin was expressed under the control of a mutant <em>ADH2</em> promoter. The clones containing 1–4 gene copy numbers of the chymosin were constructed using the <em>in vitro</em> cloning method, and the effect of chaperone protein on chymosin secretion was investigated.</div><div>The enzyme production levels are 4, 6.3, 4.5, and 3 IMCU/mL for 1, 2, 3, and 4-copy clones. The secreted chymosin levels increased up to two copies, and increasing the number of copies decreased the secretion level. Therefore, <em>PpPDI</em> was over-expressed in the clones regulated with the <em>ADH2</em> promoter. The over-expression of <em>PDI</em> gene increased chymosin secretion in clones compared to the counterpart host. However, the highest chymosin level was obtained with C2 (2-copy chymosin containing clone; 6.3 IMCU/mL) and C2P2 (2-copy chymosin/2-copy PDI containing clone; 8.2 IMCU/mL).</div><div>The maximum production was 39 IMCU/mL with the clone C2P2 in the fermenter scale production. The enzyme activity increased approximately 2-fold by adding two copies of the chaperone protein. The combined effect of gene copy number and chaperone overexpression on chymosin production was investigated. Two copies of the chymosin and <em>PpPDI</em> genes were the optimum among the tested clones.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106636"},"PeriodicalIF":1.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142771663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient purification and excitation energy transfer characterization of phycoerythrin 545 from Rhodomonas sp.","authors":"Yang Pu ,&nbsp;Shuo Dong ,&nbsp;Jiayu Wang ,&nbsp;Min Li ,&nbsp;Kai Dong ,&nbsp;Wenjun Li ,&nbsp;Zhihong Tang","doi":"10.1016/j.pep.2024.106634","DOIUrl":"10.1016/j.pep.2024.106634","url":null,"abstract":"<div><div>Cryptomonad phycoerythrin 545 (PE545) is an important type of phycobiliprotein in basic research and technological innovations. Herein, we report a minimalistic hydrophobic chromatography method for its purification. High purity was achieved, with a purity ratio (<em>A</em>₅₄₅/<em>A</em>₂₈₀) of 13.66 and a recovery ratio of 78.63 %. Following SDS-PAGE, Coomassie Brilliant Blue staining revealed three bands at 9 kDa, 10 kDa, and 20 kDa, corresponding to α₁, α₂ and β subunits. Multiple spectral characteristics were analyzed to ensure that optical activity was consistent with that of the natural protein. Absorption and fluorescence spectroscopies of purified PE545 displayed a strong absorption peak at 545 nm, a shoulder peak at 564 nm, and a fluorescence emission peak at 587 nm, which confirmed unchanged energy transfer properties. Furthermore, the structural and functional integrity, especially the existence of strongly coupled central chromophore pairs with excitation delocalization, was verified by circular dichroism and ultrafast absorption spectroscopy. From the studies of ultrafast absorption spectroscopy of excitation energy transfer (EET) of PE545, four decay components with lifetimes at 0.5 ps, 2.2 ps, 63 ps, and 3000 ps were obtained. In addition, the dynamics of these components confirmed the EET pathways from the central PEB chromophore pairs to the peripheral pigments and localized in the lowest state. Our work will be of considerable value for both fundamental research and applications of PE545.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106634"},"PeriodicalIF":1.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and crystallization of copper resistance protein B (CopB) from Acinetobacter baumannii","authors":"Niloofar Nayeri ,&nbsp;Kamil Górecki ,&nbsp;Karin Lindkvist-Petersson ,&nbsp;Pontus Gourdon ,&nbsp;Ping Li","doi":"10.1016/j.pep.2024.106635","DOIUrl":"10.1016/j.pep.2024.106635","url":null,"abstract":"<div><div><em>Acinetobacter baumannii</em> (<em>A. baumannii</em>) is an opportunistic, Gram-negative human pathogen, which is predominantly found in hospital patients. Its antimicrobial resistance is escalating, leading to less efficient treatments, and an increasing interest in identifying new therapeutic drugs. Metals as antimicrobials are vital in healthcare and agriculture, and copper-containing surfaces are known to reduce microbial counts, also in clinical settings. Indeed, copper (Cu) is an essential element required for survival in all organisms from bacteria to humans, but nevertheless elevated levels are highly toxic for cells. Through different regulatory mechanisms, cells maintain Cu homeostasis, and ion channels and transporters are critical in this process. Precise understanding of such ion transport requires insight into the protein structures of the involved proteins, which will also provide information important for applied sciences. Considering the medical significance of <em>A. baumannii</em> and the possibility to exploit Cu to handle such infections, channels and transporters represent appealing targets. Here we approached the putative outer membrane CopB (Copper resistance protein B) from <em>A. baumannii</em> that is postulated to conduct Cu, with characterization of its structure and function as well as to enable rational drug-design. To this end, we demonstrate in this work procedures to produce purified sample and to recover diffracting protein crystals of CopB. The protein was overproduced in <em>E. coli</em> and membrane extracted in a range of detergents. The solubilized protein was subjected to crystallization, which yielded hits that scatter X-rays to low resolution. Our findings have the potential to pave the way for subsequent drug discovery.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106635"},"PeriodicalIF":1.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expression and purification of the intact bacterial ergothioneine transporter EgtU","authors":"Katherine A. Edmonds,&nbsp;Karla Diaz-Rodriguez,&nbsp;David P. Giedroc","doi":"10.1016/j.pep.2024.106633","DOIUrl":"10.1016/j.pep.2024.106633","url":null,"abstract":"<div><div>The bacterial ATP-binding cassette (ABC) transporter EgtU is responsible for uptake of the cellular antioxidant ergothioneine in <em>Streptococcus pneumoniae</em>, and it has homologs in a surprisingly diverse range of microbial pathogens. Crystal structures have been reported for the solute binding domain of EgtU, but many details of the structure and function of the intact heterotetrameric transporter remain to be elucidated. In this study, we have expressed <em>S. pneumoniae</em> EgtU and purified it from <em>E. coli</em> BL21 (DE3) with high purity and homogeneity. Our preliminary data establish ergothioneine binding and ATP hydrolysis by the full-length transporter solubilized in DDM micelles. Our workflow allows for isolation of suitable quantities of EgtU for ongoing structural studies and detailed biophysical characterization.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106633"},"PeriodicalIF":1.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142693469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recombinant human FOXJ1 protein binds DNA, forms higher-order oligomers, has gel-shifting domains and contains intrinsically disordered regions","authors":"Shashank Arora,&nbsp;Pawan Nagarkar,&nbsp;Jacinta S. D'Souza","doi":"10.1016/j.pep.2024.106622","DOIUrl":"10.1016/j.pep.2024.106622","url":null,"abstract":"<div><div>Forkhead box protein J1 (FOXJ1) is the key transcriptional regulator during the conversion of mammalian primary cilium with a 9 + 0 architecture to the motile (9 + 2) one. The nucleotide sequences of the full-length and DNA-binding domain (DBD) of the open reading frame (ORF) were isolated and expressed into <em>E. coli</em> as 6xHis-tagged proteins. Upon induction, the DBD formed inclusion bodies that solubilized with 8 M urea. No induction of 6xHis-FOXJ1 protein was seen despite sub-cloning into several expression vectors and <em>E. coli</em> host strains. To improve induction and solubility, the 6xHis tag was substituted with Glutathione S-transferase (GST), and weak induction was seen in <em>E. coli</em> BL21(DE3). The GST-FOXJ1 showed anomalous migration on denaturing gel electrophoresis (AM-DRE), migrating at approximately 83 kDa instead of its calculated molecular weight (<em>Mr</em>) of 72.4 kDa. It was also unstable and led to degradation products. The 6xHis tag was substituted with Glutathione S-transferase (GST) to improve induction and solubility. Codon-optimization improved the induction, but the protein still showed AM-DRE and instability. It seemed that the recombinant protein was either toxic or posed a metabolic burden to the <em>E. coli</em> cells or, once produced was prone to degradation due mainly to the lack of post-translational modification (PTM). This process is required for some eukaryotic proteins after they are manufactured in the ribosomal factory. Both the purified recombinant proteins exhibited cysteine-induced oligomerization <em>via</em> the formation of disulphide bridges since this was reduced using dithiothreitol (DTT). Both were equally functional as these individually bound to an oligonucleotide, a consensus DNA-binding sequence for FOX proteins. Further, the recombinant polypeptides corresponding to the C-terminus and N-terminus show anomalies indicating that the highly acidic residues (known as polyacidic gel-shifting domains) in these polypeptides contribute to the AM-DRE. We demonstrate for the first time that the recombinant HsFOXJ1 and its DBD bind to DNA, its polyacidic gel-shifting domains are the reason for the AM-DRE, is unstable leading to degradation products, exhibits cysteine-induced oligomerization and harbours intrinsically disordered regions.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106622"},"PeriodicalIF":1.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142644500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermostable phenylacetic acid degradation protein TtPaaI from Thermus thermophilus as a scaffold for tetravalent display of proteins","authors":"Aleksandra Chorążewska,&nbsp;Darragh Regan,&nbsp;Marta Kalka,&nbsp;Krzysztof Ciura,&nbsp;Natalia Porębska,&nbsp;Łukasz Opaliński","doi":"10.1016/j.pep.2024.106623","DOIUrl":"10.1016/j.pep.2024.106623","url":null,"abstract":"<div><div>Numerous proteins in nature strictly require oligomerization for their full activity. Moreover, the function of natural and artificial proteins can me adjusted by altering their oligomeric state, leading to development of biotechnologically-relevant biomacromolecules. Oligomerization scaffolds from natural sources and designed <em>de novo</em> enable shuffling the oligomeric state and valency of biomacromolecules. In this report we probed the scaffolding potential of the thermostable phenylacetic acid degradation protein acyl-CoA from <em>Thermus thermophilus</em> (<em>Tt</em>PaaI). We designed and successfully produced the fusion protein between <em>Tt</em>PaaI (scaffold) and galectin-7, a multifunctional lectin implicated in human diseases (ligand) and demonstrated that <em>Tt</em>PaaI can serve as a framework for functional multivalent display of ligands.</div></div>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":"227 ","pages":"Article 106623"},"PeriodicalIF":1.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142626845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}