Computational design

  • 文章类型: Journal Article
    体外选择变构核酶有许多挑战,例如复杂而耗时的实验程序,不确定的结果,和富集序列的不想要的功能。使用RNA二级结构折叠原理可以实现变构核酶的精确计算设计。变构核酶的计算设计基于实验验证的EA,随机搜索算法,和RNA折叠的分配函数。在硅设计达到了超过90%的精度。具有不同逻辑门的各种算法已经通过能够快速创建许多变构序列的计算机程序自动化。这可以消除体外选择变构核酶的需要,从而大大减少了所需的时间和成本。
    In vitro selection of allosteric ribozymes has many challenges, such as complex and time-consuming experimental procedures, uncertain results, and the unwanted functionality of the enriched sequences. The precise computational design of allosteric ribozymes is achievable using RNA secondary structure folding principles. The computational design of allosteric ribozymes is based on experimentally validated EAs, random search algorithms, and a partition function for RNA folding. The in silico design achieves an accuracy exceeding 90%. Various algorithms with different logic gates have been automated via computer programs that can quickly create many allosteric sequences. This can eliminate the need for in vitro selection of allosteric ribozymes, thus vastly reducing the time and cost required.
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  • 文章类型: Journal Article
    在过去的二十年里,治疗性抗体已成为生物制剂领域中快速扩展的结构域。可以简化抗体发现和优化过程的计算机仿真工具对于支持每年越来越多和越来越复杂的管道至关重要。高质量的结构信息对于抗体优化过程仍然至关重要,但是抗体-抗原复合物结构通常无法获得,并且计算机抗体对接方法仍然不可靠。在这项研究中,DeepAb,直接从序列预测抗体Fv结构的深度学习模型,与单点实验深度突变扫描(DMS)富集数据结合使用,以设计抗鸡蛋溶菌酶(HEL)抗体的200种潜在优化变体。我们试图确定含有来自DMS的有益突变的组合的DeepAb设计的变体是否表现出增强的热稳定性,以及这种优化是否影响它们的可显影性概况。通过强大的高通量方法生产了200种变体,并测试了热和胶体稳定性(Tonset,Tm,Tagg),相对于亲本抗体的亲和力(KD),和发育性参数(非特异性结合,聚集倾向,自我关联)。在设计的克隆中,91%和94%表现出增加的热和胶体稳定性和亲和力,分别。其中,10%显示对HEL的亲和力显着增加(增加5至21倍)和热稳定性(Tm1增加>2.5C),大多数克隆保留了亲代抗体的有利发展概况。另外的计算机模拟测试表明,即使没有首先收集实验性DMS测量,这些方法也将富集结合亲和力。这些数据打开了计算机抗体优化的可能性,而无需预测抗体-抗原界面,在没有晶体结构的情况下,这是众所周知的困难。
    Over the past two decades, therapeutic antibodies have emerged as a rapidly expanding domain within the field of biologics. In silico tools that can streamline the process of antibody discovery and optimization are critical to support a pipeline that is growing more numerous and complex every year. High-quality structural information remains critical for the antibody optimization process, but antibody-antigen complex structures are often unavailable and in silico antibody docking methods are still unreliable. In this study, DeepAb, a deep learning model for predicting antibody Fv structure directly from sequence, was used in conjunction with single-point experimental deep mutational scanning (DMS) enrichment data to design 200 potentially optimized variants of an anti-hen egg lysozyme (HEL) antibody. We sought to determine whether DeepAb-designed variants containing combinations of beneficial mutations from the DMS exhibit enhanced thermostability and whether this optimization affected their developability profile. The 200 variants were produced through a robust high-throughput method and tested for thermal and colloidal stability (Tonset, Tm, Tagg), affinity (KD) relative to the parental antibody, and for developability parameters (nonspecific binding, aggregation propensity, self-association). Of the designed clones, 91% and 94% exhibited increased thermal and colloidal stability and affinity, respectively. Of these, 10% showed a significantly increased affinity for HEL (5- to 21-fold increase) and thermostability (>2.5C increase in Tm1), with most clones retaining the favorable developability profile of the parental antibody. Additional in silico tests suggest that these methods would enrich for binding affinity even without first collecting experimental DMS measurements. These data open the possibility of in silico antibody optimization without the need to predict the antibody-antigen interface, which is notoriously difficult in the absence of crystal structures.
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  • 文章类型: Journal Article
    将二氧化碳转化为增值化学品仍然是一个巨大的挑战。琥珀酸长期以来一直被认为是顶级的积木化学品之一。这项研究报道了通过电化学和工程大肠杆菌之间的结合将CO2有效地向上循环到琥珀酸中。在这个过程中,合成了Cu-有机骨架催化剂,用于高法拉第效率的电催化CO2转化为乙醇(FE,84.7%)和相对纯度(RP,95wt%)。随后,通过结合计算设计和代谢工程,构建了一种能有效吸收CO2衍生乙醇生产琥珀酸的工程大肠杆菌,琥珀酸滴度达到53.8mM,产量为0.41mol/mol,这是82%的理论产率。这项研究努力将电催化CO2和从CO2衍生乙醇生产琥珀酸的两种有效乙醇合成过程联系起来,通过将二氧化碳转化为乙醇,为生产琥珀酸和其他增值化学品铺平了道路。
    Converting CO2 into value-added chemicals still remains a grand challenge. Succinic acid has long been considered as one of the top building block chemicals. This study reported efficiently upcycling CO2 into succinic acid by combining between electrochemical and engineered Escherichia coli. In this process, the Cu-organic framework catalyst was synthesized for electrocatalytic CO2-to-ethanol conversion with high Faradaic efficiency (FE, 84.7 %) and relative purity (RP, 95 wt%). Subsequently, an engineered E. coli with efficiently assimilating CO2-derived ethanol to produce succinic acid was constructed by combining computational design and metabolic engineering, and the succinic acid titer reached 53.8 mM with the yield of 0.41 mol/mol, which is 82 % of the theoretical yield. This study effort to link the two processes of efficient ethanol synthesis by electrocatalytic CO2 and succinic acid production from CO2-derived ethanol, paving a way for the production of succinic acid and other value-added chemicals by converting CO2 into ethanol.
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  • 文章类型: Journal Article
    本研究提出了一种设计基于MIP的电化学传感器的新方法,该传感器可以提高异丙托溴铵(IPR)的选择性和灵敏度。以甲基丙烯酸2-羟乙酯(HEMA)为基本单体,2-羟基-2-甲基苯丙酮作为引发剂,乙二醇二甲基丙烯酸酯(EGDMA)作为交联剂,和N-甲基丙烯酰基-L-天冬氨酸(MAAsp)作为功能单体。MAAsp的存在导致印迹结合位点中的官能团,而聚乙烯醇(PVA)的存在允许产生多孔材料,不仅用于灵敏的传感,而且还用于避免电子传输限制。使用循环伏安法(CV)和电化学阻抗谱(EIS)确认了MIP制备过程每个阶段变化的电化学表征。此外,使用扫描电子显微镜(SEM)对开发的传感器进行形态学表征,衰减全反射-傅里叶变换红外光谱(ATR-FTIR),和接触角测量。还进行了理论计算以更好地解释/确认实验结果。发现使用DFT方法的计算结果与实验数据一致。使用光聚合方法开发了MAAsp-IPR@MIP/GCE传感器,并且通过暴露于365nm的UV灯辐射获得传感器表面。改进的基于MIP的电化学传感器证明了在优化条件下在1.0×10-12-1.0×10-11M的线性工作范围内测量标准溶液的IPR的能力。对于标准溶液,检测限(LOD)和定量限(LOQ)分别为2.78×10-13和9.27×10-13M,分别。吸入型的IPR回收率分别为101.70%和100.34%,两种情况下的平均相对标准偏差(RSD)均小于0.76%。此外,所提出的改良传感器对快速评估吸入形式的IPR表现出显著的灵敏度和选择性。即使在存在IPR杂质的情况下,其成功的性能也证明了传感器的独特选择性。
    This study presented a new method to design a MIP-based electrochemical sensor that could improve the selective and sensitive detection of ipratropium bromide (IPR). The polymeric film was designed using 2-hydroxyethyl methacrylate (HEMA) as the basic monomer, 2-hydroxy-2-methylpropiophenone as the initiator, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, and N-methacryloyl-L-aspartic acid (MAAsp) as the functional monomer. The presence of MAAsp results in the functional groups in imprinting binding sites, while the presence of poly(vinyl alcohol) (PVA) allows the generation of porous materials not only for sensitive sensing but also for avoiding electron transport limitations. Electrochemical characterizations of the changes at each stage of the MIP preparation process were confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In addition, morphological characterizations of the developed sensor were performed using scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and contact angle measurements. Theoretical calculations were also performed to explain/confirm the experimental results better. It was found that the results of the calculations using the DFT approach agreed with the experimental data. The MAAsp-IPR@MIP/GCE sensor was developed using the photopolymerization method, and the sensor surface was obtained by exposure to UV lamp radiation at 365 nm. The improved MIP-based electrochemical sensor demonstrated the ability to measure IPR for standard solutions in the linear operating range of 1.0 × 10-12-1.0 × 10-11 M under optimized conditions. For standard solutions, the limit of detection (LOD) and limit of quantification (LOQ) were obtained as 2.78 × 10-13 and 9.27 × 10-13 M, respectively. The IPR recovery values for the inhalation form were calculated as 101.70 % and 100.34 %, and the mean relative standard deviations (RSD) were less than 0.76 % in both cases. In addition, the proposed modified sensor demonstrated remarkable sensitivity and selectivity for rapid assessment of IPR in inhalation forms. The sensor\'s unique selectivity is demonstrated by its successful performance even in the presence of IPR impurities.
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  • 文章类型: Journal Article
    在这项研究中,提出了第一种基于纳米材料支持的分子印迹聚合物(MIP)的电化学方法,以成功检测头孢地尼(CFD)。这里,使用对氨基苯甲酸(p-ABA)作为单体,并选择光聚合方法在玻碳电极(GCE)上形成MIP。将ZnO纳米颗粒(ZnONPs)添加到MIP传感器中以增加灵敏度并产生高孔隙率。通过使用循环伏安法(CV)和电化学阻抗谱(EIS),表征调查证实了MIP生产过程每个阶段的变化。电化学(循环伏安法(CV)和电化学阻抗谱(EIS))和扫描电子显微镜(SEM)方法用于研究基于MIP的纳米复合传感器的表征研究。MIP参数的测量,比如添加纳米粒子,拆卸程序,重新绑定期,单体比例,等。,使用差分脉冲伏安法(DPV)完成。研究结果表明,当添加ZnONPs时,该信号是单独使用MIP时的3倍.在优化条件下,CFD/4-ABA@ZnONPs/MIP/GCE在7.5pM至100pM的浓度范围内显示出线性响应,LOD和LOQ值为2.06pM和6.86pM,分别。阴离子,阳离子,和物质包括尿酸,抗坏血酸,扑热息痛,和多巴胺都用于选择性测试。此外,印迹因子(IF)研究使用头孢呋辛等化合物进行,头孢唑啉,头孢克肟,头孢他啶,和头孢曲松,与CFD结构相似,以及诸如噻唑基乙酰基甘氨酸肟(IMP-A)之类的杂质,噻唑基乙酰基甘氨酸肟缩醛(IMP-B),和头孢地尼内酯(IMP-E)。结果表明,所提出的传感器具有选择性的CFD,这些杂质的相对IF值证明了这一点。CFD的回收率研究成功地应用于片剂剂型样品,所开发的传感器对片剂剂型中CFD的快速检测具有显著的灵敏度和选择性。
    In this study, the first nanomaterial-supported molecularly imprinted polymer (MIP)-based electrochemical approach was proposed to achieve the successful detection of cefdinir (CFD). Here, p-amino benzoic acid (p-ABA) was used as the monomer and the photopolymerization method was chosen to form MIP on a glassy carbon electrode (GCE). ZnO nanoparticles (ZnO NPs) were added to the MIP sensor to increase sensitivity and create high porosity. Through the use of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), characterization investigations confirmed the alterations at each stage of the MIP production process. Electrochemical (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)) and scanning electron microscopy (SEM) methods were used for study the characterization studies of the MIP-based nanocomposite sensor. The measurement of MIP parameters, such as the addition of nanoparticles, the removal procedure, the rebinding period, the monomer ratio, etc., was done using the differential pulse voltammetry (DPV). The findings showed that when ZnO NPs were added, the signal was three times higher than when MIPs were used alone. Under the optimized conditions, CFD/4-ABA@ZnONPs/MIP/GCE showed a linear response in the concentration range between 7.5 pM and 100 pM with LOD and LOQ values of 2.06 pM and 6.86 pM, respectively. Anions, cations, and substances including uric acid, ascorbic acid, paracetamol, and dopamine were all used in the selectivity test. In addition, the imprinting factor (IF) study was carried out using compounds such as cefuroxime, cefazolin, cefixime, ceftazidime, and ceftriaxone, which have structural similarities with CFD, as well as impurities such as thiazolylacetyl glycine oxime (IMP-A), thiazolylacetyl glycine oxime acetal (IMP-B), and cefdinir lactone (IMP-E). The results showed that the proposed sensor was selective for CFD, as evidenced by the relative IF values of these impurities. The recovery studies of CFD were successfully applied to tablet dosage form samples, and the developed sensor demonstrated significant sensitivity and selectivity for rapid detection of CFD in tablet dosage form.
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  • 文章类型: Journal Article
    目前胰腺癌靶向治疗的有限成功强调了对新治疗方式的迫切需求。减轻这种恶性肿瘤的挑战可以归因于消化器官扩张因子(DEF)。胰腺肿瘤发生中一个关键但未被开发的因子。这项研究使用了体外和体内方法的混合,在理论分析的补充下,提出DEF作为一个有希望的抗肿瘤靶点。临床样品的分析揭示了DEF的高表达与胰腺癌患者的存活率降低相关。至关重要的是,DEF的消耗显著阻碍肿瘤生长。该研究进一步发现DEF与p65结合,使其免受癌细胞中泛素-蛋白酶体途径介导的降解。基于这些发现和计算方法,这项研究制定了一种模拟DEF的肽,肽-031,旨在破坏DEF-p65相互作用。已经在体外和体内证明了肽-031抑制肿瘤增殖的有效性。这项研究揭示了DEF的致癌作用,同时强调了其在胰腺癌中的预后价值和治疗潜力。此外,肽-031是具有有效抗肿瘤作用的有前途的治疗剂。
    The limited success of current targeted therapies for pancreatic cancer underscores an urgent demand for novel treatment modalities. The challenge in mitigating this malignancy can be attributed to the digestive organ expansion factor (DEF), a pivotal yet underexplored factor in pancreatic tumorigenesis. The study uses a blend of in vitro and in vivo approaches, complemented by the theoretical analyses, to propose DEF as a promising anti-tumor target. Analysis of clinical samples reveals that high expression of DEF is correlated with diminished survival in pancreatic cancer patients. Crucially, the depletion of DEF significantly impedes tumor growth. The study further discovers that DEF binds to p65, shielding it from degradation mediated by the ubiquitin-proteasome pathway in cancer cells. Based on these findings and computational approaches, the study formulates a DEF-mimicking peptide, peptide-031, designed to disrupt the DEF-p65 interaction. The effectiveness of peptide-031 in inhibiting tumor proliferation has been demonstrated both in vitro and in vivo. This study unveils the oncogenic role of DEF while highlighting its prognostic value and therapeutic potential in pancreatic cancer. In addition, peptide-031 is a promising therapeutic agent with potent anti-tumor effects.
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  • 文章类型: Journal Article
    二硫化碳(CS2)是一种环境污染物,这对长期或急性暴露的工人来说是致命的危险。然而,CS2的毒性机制尚不清楚,由于生物相容性供体的稀缺性,它可以在细胞中释放CS2。在这里,我们基于中离子1,3-噻唑5-硫醇盐(TAT)和应变环辛炔外切BCN-OH之间的“点击和释放”反应,开发了第一个生物正交CS2递送系统。我们成功地实现了细胞内CS2的释放,并研究了CS2诱导的肝毒性的原因,包括氧化应激,蛋白毒性应激和铜依赖性细胞死亡。发现CS2与细胞质中的亲核试剂反应后,可以成为绕过铜转运蛋白的铜载体,和额外的铜补充将加剧细胞内稳态的丧失和最终细胞死亡。这些发现启发我们通过在我们的CS2递送系统中引入铜螯合基团来探索CS2与铜结合的抗癌活性。
    Carbon disulfide (CS2) is an environmental contaminant, which is deadly hazardous to the workers under chronic or acute exposure. However, the toxicity mechanisms of CS2 are still unclear due to the scarcity of biocompatible donors, which can release CS2 in cells. Here we developed the first bioorthogonal CS2 delivery system based on the \"click-and-release\" reactions between mesoionic 1,3-thiazolium-5-thiolates (TATs) and strained cyclooctyne exo-BCN-OH. We successfully realized intracellular CS2 release and investigated the causes of CS2-induced hepatotoxicity, including oxidative stress, proteotoxic stress and copper-dependent cell death. It is found that CS2 can be copper vehicles bypassing copper transporters after reacting with nucleophiles in cytoplasm, and extra copper supplementation will exacerbate the loss of homeostasis of cells and ultimately cell death. These findings inspired us to explore the anticancer activity of CS2 in combination with copper by introducing a copper chelating group in our CS2 delivery system.
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  • 文章类型: Journal Article
    随着严重急性呼吸系统综合症冠状病毒2(SARS-CoV-2)继续在全球传播,仍需要探索新的治疗和诊断策略.病毒通过刺突蛋白结合血管紧张素转换酶2(ACE2)受体进入宿主细胞。这里,我们开发了一个工程,小,稳定,和无催化活性的ACE2,称为微型ACE2(mACE2),旨在以高亲和力结合刺突蛋白。采用基于磁性纳米粒子的检测方法,我们利用mACE2的强结合亲和力来开发用于检测或中和SARS-CoV-2的敏感和特异性平台。我们的发现强调了工程化mACE2作为对抗SARS-CoV-2的有价值工具的潜力。基于分段分子设计开发这种小试剂的成功作为快速部署这种试剂以诊断和对抗其他病毒性疾病的概念验证方法。
    As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues its global spread, the exploration of novel therapeutic and diagnostic strategies is still needed. The virus enters host cells by binding the angiotensin-converting enzyme 2 (ACE2) receptor through the spike protein. Here, we develop an engineered, small, stable, and catalytically inactive version of ACE2, termed miniature ACE2 (mACE2), designed to bind the spike protein with high affinity. Employing a magnetic nanoparticle-based assay, we harnessed the strong binding affinity of mACE2 to develop a sensitive and specific platform for the detection or neutralization of SARS-CoV-2. Our findings highlight the potential of engineered mACE2 as a valuable tool in the fight against SARS-CoV-2. The success of developing such a small reagent based on a piecewise molecular design serves as a proof-of-concept approach for the rapid deployment of such agents to diagnose and fight other viral diseases.
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  • 文章类型: Journal Article
    稳定蛋白质而不妨碍其功能是蛋白质工程和设计中的中心任务。PYR1是一种植物激素受体,已被设计为结合不同的小分子配体。我们寻找了一组广义突变,其将提供稳定性而不影响具有不同配体结合能力的PYR1变体的功能性。为此,我们使用了全局多突变分析(GMMA)方法,它可以识别具有稳定作用且不会降低功能的替代。GMMA具有发现在不同序列环境中稳定的取代的额外益处,并且我们假设将GMMA应用于具有不同功能的PYR1将鉴定这组广义突变。的确,对具有两种不同功能的PYR1变体的文库进行FACS和深度测序,并应用GMMA分析鉴定出5个取代,当插入到四个PYR1变体中时,每个变体都结合一个独特的配体,提供了2°C-6°C的热失活温度的增加和功能没有降低。
    Stabilizing proteins without otherwise hampering their function is a central task in protein engineering and design. PYR1 is a plant hormone receptor that has been engineered to bind diverse small molecule ligands. We sought a set of generalized mutations that would provide stability without affecting functionality for PYR1 variants with diverse ligand-binding capabilities. To do this we used a global multi-mutant analysis (GMMA) approach, which can identify substitutions that have stabilizing effects and do not lower function. GMMA has the added benefit of finding substitutions that are stabilizing in different sequence contexts and we hypothesized that applying GMMA to PYR1 with different functionalities would identify this set of generalized mutations. Indeed, conducting FACS and deep sequencing of libraries for PYR1 variants with two different functionalities and applying a GMMA analysis identified 5 substitutions that, when inserted into four PYR1 variants that each bind a unique ligand, provided an increase of 2-6 °C in thermal inactivation temperature and no decrease in functionality.
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  • 文章类型: Journal Article
    烟酰胺腺嘌呤二核苷酸磷酸(NADPH),作为一个众所周知的辅因子,广泛用于大多数酶促氧化还原反应,在工业催化中发挥着重要作用。然而,缺乏有效的NADP与NADPH辅因子再生的可比方法从根本上损害了有效的绿色化学合成。酒精脱氢酶(ADH)酶,允许氧化还原辅因子NADPH的原位再生,具有高比活性和易于副产物分离过程,具有巨大的工业应用潜力和研究关注。因此,本文选择了来自贝氏梭菌的NADP特异性ADH进行工程改造以进行辅因子回收,使用名为蛋白质修复一站式服务(PROSS)的自动算法。突变体CbADH-6M(S24P/G182A/G196A/H222D/S250E/S254R)表现出良好的可溶性和高活性表达,活性为46.3U/mL,比野生型(2.9U/mL)高16倍,和更稳定的蛋白质构象,具有增强的热稳定性:ΔT1/260分钟=3.6°C(孵育60分钟后50%失活的温度)。此外,通过重组大肠杆菌的高细胞密度发酵策略,将CbADH-6M的活性上调至2401.8U/mL,展示其工业潜力。最后,在一些精细的手性芳族醇与另一种从开菲尔乳杆菌(LkADH)中的ADH偶联的合成中,证明了突变酶的NADPH再生的出色效率。
    Nicotinamide adenine dinucleotide phosphate (NADPH), as a well-known cofactor, is widely used in the most of enzymatic redox reactions, playing an important role in industrial catalysis. However, the absence of a comparable method for efficient NADP+ to NADPH cofactor regeneration radically impairs efficient green chemical synthesis. Alcohol dehydrogenase (ADH) enzymes, allowing the in situ regeneration of the redox cofactor NADPH with high specific activity and easy by-product separation process, are provided with great industrial application potential and research attention. Accordingly, herein a NADP+-specific ADH from Clostridium beijerinckii was selected to be engineered for cofactor recycle, using an automated algorithm named Protein Repair One-stop Shop (PROSS). The mutant CbADH-6M (S24P/G182A/G196A/H222D/S250E/S254R) exhibited a favorable soluble and highly active expression with an activity of 46.3 U/mL, which was 16 times higher than the wild type (2.9 U/mL), and a more stable protein conformation with an enhanced thermal stability: Δ T 1 / 2 60 min =  + 3.6 °C (temperature of 50% inactivation after incubation for 60 min). Furthermore, the activity of CbADH-6M was up-graded to 2401.8 U/mL by high cell density fermentation strategy using recombinant Escherichia coli, demonstrating its industrial potential. Finally, the superb efficiency for NADPH regeneration of the mutant enzyme was testified in the synthesis of some fine chiral aromatic alcohols coupling with another ADH from Lactobacillus kefir (LkADH).
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