Pub Date : 2024-06-24DOI: 10.1021/acschembio.4c00221
Elise D Ficaretta, Soumya Jyoti Singha Roy, Lena Voss, Abhishek Chatterjee
Site-specific noncanonical amino acid (ncAA) mutagenesis in living cells has traditionally relied on heterologous, nonsense-suppressing aminoacyl-tRNA synthetase (aaRS)/tRNA pairs that do not cross-react with their endogenous counterparts. Such heterologous pairs often perform suboptimally in a foreign host cell since they were not evolutionarily optimized to function in the foreign environment. This suboptimal performance restricts the number of ncAAs that can be simultaneously incorporated into a protein. Here, we show that the use of an endogenous aaRS/tRNA pair to drive ncAA incorporation can offer a potential solution to this limitation. To this end, we developed an engineered Escherichia coli strain (ATMY-C321), wherein the endogenous tyrosyl-tRNA synthetase (TyrRS)/tRNA pair has been functionally replaced with an archaeal counterpart, and the release factor 1 has been removed to eliminate competing termination at the UAG nonsense codons. The endogenous TyrRS/tRNACUATyr pair exhibits remarkably efficient nonsense suppression in the resulting cell, relative to established orthogonal ncAA-incorporation systems in E. coli, allowing the incorporation of an ncAA at up to 10 contiguous sites in a reporter protein. Our work highlights the limitations of orthogonal translation systems using heterologous aaRS/tRNA pairs and offers a potential alternative involving the use of endogenous pairs.
{"title":"Native Aminoacyl-tRNA Synthetase/tRNA Pair Drives Highly Efficient Noncanonical Amino Acid Incorporation in <i>Escherichia coli</i>.","authors":"Elise D Ficaretta, Soumya Jyoti Singha Roy, Lena Voss, Abhishek Chatterjee","doi":"10.1021/acschembio.4c00221","DOIUrl":"https://doi.org/10.1021/acschembio.4c00221","url":null,"abstract":"<p><p>Site-specific noncanonical amino acid (ncAA) mutagenesis in living cells has traditionally relied on heterologous, nonsense-suppressing aminoacyl-tRNA synthetase (aaRS)/tRNA pairs that do not cross-react with their endogenous counterparts. Such heterologous pairs often perform suboptimally in a foreign host cell since they were not evolutionarily optimized to function in the foreign environment. This suboptimal performance restricts the number of ncAAs that can be simultaneously incorporated into a protein. Here, we show that the use of an endogenous aaRS/tRNA pair to drive ncAA incorporation can offer a potential solution to this limitation. To this end, we developed an engineered <i>Escherichia coli</i> strain (ATMY-C321), wherein the endogenous tyrosyl-tRNA synthetase (TyrRS)/tRNA pair has been functionally replaced with an archaeal counterpart, and the release factor 1 has been removed to eliminate competing termination at the UAG nonsense codons. The endogenous TyrRS/tRNA<sub>CUA</sub><sup>Tyr</sup> pair exhibits remarkably efficient nonsense suppression in the resulting cell, relative to established orthogonal ncAA-incorporation systems in <i>E. coli</i>, allowing the incorporation of an ncAA at up to 10 contiguous sites in a reporter protein. Our work highlights the limitations of orthogonal translation systems using heterologous aaRS/tRNA pairs and offers a potential alternative involving the use of endogenous pairs.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-24DOI: 10.1021/acschembio.4c00196
Mu-Rong Kao, Tzu-Hsuan Ma, Hsiang-Yu Chou, Shu-Chieh Chang, Lin-Chen Cheng, Kuo-Shiang Liao, Jiun-Jie Shie, Philip J Harris, Chi-Huey Wong, Yves S Y Hsieh
Eliminating the core fucose from the N-glycans of the Fc antibody segment by pathway engineering or enzymatic methods has been shown to enhance the potency of therapeutic antibodies, especially in the context of antibody-dependent cytotoxicity (ADCC). However, there is a significant challenge due to the limited defucosylation efficiency of commercially available α-l-fucosidases. In this study, we report a unique α-l-fucosidase (PnfucA) from the bacterium Prevotella nigrescens that has a low sequence identity compared with all other known α-l-fucosidases and is highly reactive toward a core disaccharide substrate with fucose α(1,3)-, α (1,4)-and α(1,6)-linked to GlcNAc, and is less reactive toward the Fuc-α(1,2)-Gal on the terminal trisaccharide of the oligosaccharide Globo H (Bb3). The kinetic properties of the enzyme, such as its Km and kcat, were determined and the optimized expression of PnfucA gave a yield exceeding 30 mg/L. The recombinant enzyme retained its full activity even after being incubated for 6 h at 37 °C. Moreover, it retained 92 and 87% of its activity after freezing and freeze-drying treatments, respectively, for over 28 days. In a representative glycoengineering of adalimumab (Humira), PnfucA showed remarkable hydrolytic efficiency in cleaving the α(1,6)-linked core fucose from FucGlcNAc on the antibody with a quantitative yield. This enabled the seamless incorporation of biantennary sialylglycans by Endo-S2 D184 M in a one-pot fashion to yield adalimumab in a homogeneous afucosylated glycoform with an improved binding affinity toward Fcγ receptor IIIa.
通过途径工程或酶法消除 Fc 抗体片段 N-聚糖中的核心岩藻糖已被证明可提高治疗性抗体的效力,尤其是在抗体依赖性细胞毒性(ADCC)方面。然而,由于市售的α-l-岩藻糖苷酶的去核糖效率有限,因此面临着巨大的挑战。在这项研究中,我们报告了一种独特的α-l-岩藻糖苷酶(PnfucA),它来自于黑前真菌(Prevotella nigrescens),与所有其他已知的α-l-岩藻糖苷酶相比,其序列同一性较低,而且对岩藻糖核心二糖底物α(1、3)-、α(1,4)-和α(1,6)-与 GlcNAc 连接的核心二糖底物具有高活性,而对寡糖 Globo H(Bb3)末端三糖上的 Fuc-α(1,2)-Gal 反应性较低。测定了该酶的动力学特性,如 Km 和 kcat,优化表达的 PnfucA 产率超过 30 mg/L。重组酶在 37 °C 下培养 6 小时后仍能保持其全部活性。此外,经过 28 天以上的冷冻和冻干处理后,重组酶的活性分别保持了 92% 和 87%。在具有代表性的阿达木单抗(Humira)糖工程中,PnfucA 在从抗体上的 FucGlcNAc 中裂解 α(1,6)-连接核心岩藻糖方面表现出了显著的水解效率,而且产量可观。这样,Endo-S2 D184 M 就能以一锅煮的方式无缝地加入双烯酰基聚糖,从而得到阿达木单抗的均质afucosylated糖型,并提高了与 Fcγ 受体 IIIa 的结合亲和力。
{"title":"A Robust α-l-Fucosidase from <i>Prevotella nigrescens</i> for Glycoengineering Therapeutic Antibodies.","authors":"Mu-Rong Kao, Tzu-Hsuan Ma, Hsiang-Yu Chou, Shu-Chieh Chang, Lin-Chen Cheng, Kuo-Shiang Liao, Jiun-Jie Shie, Philip J Harris, Chi-Huey Wong, Yves S Y Hsieh","doi":"10.1021/acschembio.4c00196","DOIUrl":"https://doi.org/10.1021/acschembio.4c00196","url":null,"abstract":"<p><p>Eliminating the core fucose from the <i>N</i>-glycans of the Fc antibody segment by pathway engineering or enzymatic methods has been shown to enhance the potency of therapeutic antibodies, especially in the context of antibody-dependent cytotoxicity (ADCC). However, there is a significant challenge due to the limited defucosylation efficiency of commercially available α-l-fucosidases. In this study, we report a unique α-l-fucosidase (<i>Pn</i>fucA) from the bacterium <i>Prevotella nigrescens</i> that has a low sequence identity compared with all other known α-l-fucosidases and is highly reactive toward a core disaccharide substrate with fucose α(1,3)-, α (1,4)-and α(1,6)-linked to GlcNAc, and is less reactive toward the Fuc-α(1,2)-Gal on the terminal trisaccharide of the oligosaccharide Globo H (Bb3). The kinetic properties of the enzyme, such as its <i>K</i><sub>m</sub> and <i>k</i><sub>cat</sub>, were determined and the optimized expression of <i>Pn</i>fucA gave a yield exceeding 30 mg/L. The recombinant enzyme retained its full activity even after being incubated for 6 h at 37 °C. Moreover, it retained 92 and 87% of its activity after freezing and freeze-drying treatments, respectively, for over 28 days. In a representative glycoengineering of adalimumab (Humira), <i>Pn</i>fucA showed remarkable hydrolytic efficiency in cleaving the α(1,6)-linked core fucose from FucGlcNAc on the antibody with a quantitative yield. This enabled the seamless incorporation of biantennary sialylglycans by Endo-S2 D184 M in a one-pot fashion to yield adalimumab in a homogeneous afucosylated glycoform with an improved binding affinity toward Fcγ receptor IIIa.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141441697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-24DOI: 10.1021/acschembio.3c00203
Jan Pascal Kahler, Shanping Ji, Femke Speelman-Rooms, Roeland Vanhoutte, Steven H L Verhelst
Quenched activity-based probes (qABP) are invaluable tools to visualize aberrant protease activity. Unfortunately, most studies so far have only focused on cysteine proteases, and only a few studies describe the synthesis and use of serine protease qABPs. We recently used phosphinate ester electrophiles as a novel type of reactive group to construct ABPs for serine proteases. Here, we report on the construction of qABPs based on the phosphinate warhead, exemplified by probes for the neutrophil serine proteases. The most successful probes show sub-stoichiometric reaction with human neutrophil elastase, efficient fluorescence quenching, and rapid unquenching of fluorescence upon reaction with target proteases.
{"title":"Phosphinate Esters as Novel Warheads for Quenched Activity-Based Probes Targeting Serine Proteases.","authors":"Jan Pascal Kahler, Shanping Ji, Femke Speelman-Rooms, Roeland Vanhoutte, Steven H L Verhelst","doi":"10.1021/acschembio.3c00203","DOIUrl":"10.1021/acschembio.3c00203","url":null,"abstract":"<p><p>Quenched activity-based probes (qABP) are invaluable tools to visualize aberrant protease activity. Unfortunately, most studies so far have only focused on cysteine proteases, and only a few studies describe the synthesis and use of serine protease qABPs. We recently used phosphinate ester electrophiles as a novel type of reactive group to construct ABPs for serine proteases. Here, we report on the construction of qABPs based on the phosphinate warhead, exemplified by probes for the neutrophil serine proteases. The most successful probes show sub-stoichiometric reaction with human neutrophil elastase, efficient fluorescence quenching, and rapid unquenching of fluorescence upon reaction with target proteases.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-24DOI: 10.1021/acschembio.4c00204
Ruoxi Wu, Susmita Khamrui, Tetyana Dodatko, João Leandro, Amanda Sabovic, Sara Violante, Justin R Cross, Eric Marsan, Kunal Kumar, Robert J DeVita, Michael B Lazarus, Sander M Houten
Glutaric Aciduria Type 1 (GA1) is a serious inborn error of metabolism with no pharmacological treatments. A novel strategy to treat this disease is to divert the toxic biochemical intermediates to less toxic or nontoxic metabolites. Here, we report a putative novel target, succinyl-CoA:glutarate-CoA transferase (SUGCT), which we hypothesize suppresses the GA1 metabolic phenotype through decreasing glutaryl-CoA and the derived 3-hydroxyglutaric acid. SUGCT is a type III CoA transferase that uses succinyl-CoA and glutaric acid as substrates. We report the structure of SUGCT, develop enzyme- and cell-based assays, and identify valsartan and losartan carboxylic acid as inhibitors of the enzyme in a high-throughput screen of FDA-approved compounds. The cocrystal structure of SUGCT with losartan carboxylic acid revealed a novel pocket in the active site and further validated the high-throughput screening approach. These results may form the basis for the future development of new pharmacological intervention to treat GA1.
戊二酸尿症 1 型(GA1)是一种严重的先天性代谢错误,目前尚无药物治疗方法。治疗这种疾病的新策略是将有毒的生化中间产物转化为毒性较低或无毒的代谢物。在这里,我们报告了一个假定的新靶点--琥珀酰-CoA:戊二酸-CoA 转移酶(SUGCT),我们假设它能通过减少戊二酸-CoA 和衍生的 3-羟基戊二酸来抑制 GA1 代谢表型。SUGCT 是一种 III 型 CoA 转移酶,以琥珀酰-CoA 和戊二酸为底物。我们报告了 SUGCT 的结构,开发了基于酶和细胞的检测方法,并在 FDA 批准化合物的高通量筛选中确定缬沙坦和洛沙坦羧酸为该酶的抑制剂。SUGCT 与洛沙坦羧酸的共晶体结构揭示了活性位点中的一个新口袋,进一步验证了高通量筛选方法。这些结果可能为今后开发治疗 GA1 的新药理干预措施奠定基础。
{"title":"Characterization, Structure, and Inhibition of the Human Succinyl-CoA:glutarate-CoA Transferase, a Putative Genetic Modifier of Glutaric Aciduria Type 1.","authors":"Ruoxi Wu, Susmita Khamrui, Tetyana Dodatko, João Leandro, Amanda Sabovic, Sara Violante, Justin R Cross, Eric Marsan, Kunal Kumar, Robert J DeVita, Michael B Lazarus, Sander M Houten","doi":"10.1021/acschembio.4c00204","DOIUrl":"10.1021/acschembio.4c00204","url":null,"abstract":"<p><p>Glutaric Aciduria Type 1 (GA1) is a serious inborn error of metabolism with no pharmacological treatments. A novel strategy to treat this disease is to divert the toxic biochemical intermediates to less toxic or nontoxic metabolites. Here, we report a putative novel target, succinyl-CoA:glutarate-CoA transferase (SUGCT), which we hypothesize suppresses the GA1 metabolic phenotype through decreasing glutaryl-CoA and the derived 3-hydroxyglutaric acid. SUGCT is a type III CoA transferase that uses succinyl-CoA and glutaric acid as substrates. We report the structure of SUGCT, develop enzyme- and cell-based assays, and identify valsartan and losartan carboxylic acid as inhibitors of the enzyme in a high-throughput screen of FDA-approved compounds. The cocrystal structure of SUGCT with losartan carboxylic acid revealed a novel pocket in the active site and further validated the high-throughput screening approach. These results may form the basis for the future development of new pharmacological intervention to treat GA1.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-24DOI: 10.1021/acschembio.4c00278
Marcus Foo, Luke R Frietze, Behnam Enghiad, Yujie Yuan, Christopher D Katanski, Huimin Zhao, Tao Pan
tRNA modifications help maintain tRNA structure and facilitate translation and stress response. Found in all three kingdoms of life, m1A tRNA modification occurs in the T loop of many tRNAs, stabilizes tertiary tRNA structure, and impacts translation. M1A in the T loop is reversible by three mammalian demethylase enzymes, which bypasses the need of turning over the tRNA molecule to adjust its m1A levels in cells. However, no prokaryotic tRNA demethylase enzyme has been identified that acts on endogenous RNA modifications. Using Streptomyces venezuelae as a model organism, we confirmed the presence and quantitative m1A tRNA signatures using mass spectrometry and high-throughput tRNA sequencing. We identified two RNA demethylases that can remove m1A in tRNA and validated the activity of a previously annotated tRNA m1A writer. Using single-gene knockouts of these erasers and the m1A writer, we found dynamic changes of m1A levels in many tRNAs under stress conditions. Phenotypic characterization highlighted changes in their growth and altered antibiotic production. Our identification of the first prokaryotic tRNA demethylase enzyme paves the way for investigating new mechanisms of translational regulation in bacteria.
{"title":"Prokaryotic RNA N1-Methyladenosine Erasers Maintain tRNA m1A Modification Levels in <i>Streptomyces venezuelae</i>.","authors":"Marcus Foo, Luke R Frietze, Behnam Enghiad, Yujie Yuan, Christopher D Katanski, Huimin Zhao, Tao Pan","doi":"10.1021/acschembio.4c00278","DOIUrl":"https://doi.org/10.1021/acschembio.4c00278","url":null,"abstract":"<p><p>tRNA modifications help maintain tRNA structure and facilitate translation and stress response. Found in all three kingdoms of life, m<sup>1</sup>A tRNA modification occurs in the T loop of many tRNAs, stabilizes tertiary tRNA structure, and impacts translation. M<sup>1</sup>A in the T loop is reversible by three mammalian demethylase enzymes, which bypasses the need of turning over the tRNA molecule to adjust its m<sup>1</sup>A levels in cells. However, no prokaryotic tRNA demethylase enzyme has been identified that acts on endogenous RNA modifications. Using <i>Streptomyces venezuelae</i> as a model organism, we confirmed the presence and quantitative m<sup>1</sup>A tRNA signatures using mass spectrometry and high-throughput tRNA sequencing. We identified two RNA demethylases that can remove m<sup>1</sup>A in tRNA and validated the activity of a previously annotated tRNA m<sup>1</sup>A writer. Using single-gene knockouts of these erasers and the m<sup>1</sup>A writer, we found dynamic changes of m<sup>1</sup>A levels in many tRNAs under stress conditions. Phenotypic characterization highlighted changes in their growth and altered antibiotic production. Our identification of the first prokaryotic tRNA demethylase enzyme paves the way for investigating new mechanisms of translational regulation in bacteria.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141441698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-23DOI: 10.1021/acschembio.4c00169
Matthew G Miyada, Yuran Choi, Ramunas Stepanauskas, Tanja Woyke, James J La Clair, Michael D Burkart
Carrier proteins (CPs) play a fundamental role in the biosynthesis of fatty acids, polyketides, and non-ribosomal peptides, encompassing many medicinally and pharmacologically relevant compounds. Current approaches to analyze novel carrier-protein-dependent synthetic pathways are hampered by a lack of activity-based assays for natural product biosynthesis. To fill this gap, we turned to 3-methoxychromones, highly solvatochromic fluorescent molecules whose emission intensity and wavelength are heavily dependent on their immediate molecular environment. We have developed a solvatochromic carrier-protein-targeting probe which is able to selectively fluoresce when bound to a target carrier protein. Additionally, the probe displays distinct responses upon CP binding in carrier-protein-dependent synthases. This discerning approach demonstrates the design of solvatochromic fluorophores with the ability to identify biosynthetically active CP-enzyme interactions.
{"title":"Fluorometric Analysis of Carrier-Protein-Dependent Biosynthesis through a Conformationally Sensitive Solvatochromic Pantetheinamide Probe.","authors":"Matthew G Miyada, Yuran Choi, Ramunas Stepanauskas, Tanja Woyke, James J La Clair, Michael D Burkart","doi":"10.1021/acschembio.4c00169","DOIUrl":"https://doi.org/10.1021/acschembio.4c00169","url":null,"abstract":"<p><p>Carrier proteins (CPs) play a fundamental role in the biosynthesis of fatty acids, polyketides, and non-ribosomal peptides, encompassing many medicinally and pharmacologically relevant compounds. Current approaches to analyze novel carrier-protein-dependent synthetic pathways are hampered by a lack of activity-based assays for natural product biosynthesis. To fill this gap, we turned to 3-methoxychromones, highly solvatochromic fluorescent molecules whose emission intensity and wavelength are heavily dependent on their immediate molecular environment. We have developed a solvatochromic carrier-protein-targeting probe which is able to selectively fluoresce when bound to a target carrier protein. Additionally, the probe displays distinct responses upon CP binding in carrier-protein-dependent synthases. This discerning approach demonstrates the design of solvatochromic fluorophores with the ability to identify biosynthetically active CP-enzyme interactions.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141439878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.1021/acschembio.4c00052
Carmel L Howe, David Icka-Araki, Alexander E G Viray, Sarahi Garza, James A Frank
Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel that is important for nociception and inflammatory pain and is activated by a variety of nociceptive stimuli─including lipids such as capsaicin (CAP) and endocannabinoids. TRPV1's role in physiological systems is often studied by activating it with externally perfused ligands; however, this approach is plagued by poor spatiotemporal resolution. Lipid agonists are insoluble in physiological buffers and can permeate membranes to accumulate nonselectively inside cells, where they can have off-target effects. To increase the spatiotemporal precision with which we can activate lipids on cells and tissues, we previously developed optically cleavable targeted (OCT) ligands, which use protein tags (SNAP-tags) to localize a photocaged ligand on a target cellular membrane. After enrichment, the active ligand is released on a flash of light to activate nearby receptors. In our previous work, we developed an OCT-ligand to control a cannabinoid-sensitive GPCR. Here, we expand the scope of OCT-ligand technology to target TRPV1 ion channels. We synthesize a probe, OCT-CAP, that tethers to membrane-bound SNAP-tags and releases a TRPV1 agonist when triggered by UV-A irradiation. Using Ca2+ imaging and electrophysiology in HEK293T cells expressing TRPV1, we demonstrate that OCT-CAP uncaging activates TRPV1 with superior spatiotemporal precision when compared to standard diffusible ligands or photocages. This study is the first example of an OCT-ligand designed to manipulate an ion-channel target. We anticipate that these tools will find many applications in controlling lipid signaling pathways in various cells and tissues.
瞬时受体电位类香草素 1(TRPV1)是一种非选择性阳离子通道,对痛觉和炎症性疼痛非常重要,可被多种痛觉刺激物激活--包括脂质,如辣椒素(CAP)和内源性大麻素。研究 TRPV1 在生理系统中的作用时,通常使用外部灌注的配体激活 TRPV1;然而,这种方法存在时空分辨率低的问题。脂质激动剂不溶于生理缓冲液,可穿透细胞膜在细胞内非选择性聚集,产生脱靶效应。为了提高激活细胞和组织上脂质的时空精确度,我们之前开发了光学可裂解靶向(OCT)配体,这种配体使用蛋白质标签(SNAP-标签)将光笼配体定位在目标细胞膜上。富集后,活性配体在闪光时释放出来,激活附近的受体。在我们之前的工作中,我们开发了一种 OCT 配体来控制大麻素敏感的 GPCR。在这里,我们将 OCT 配体技术的范围扩大到针对 TRPV1 离子通道。我们合成了一种探针 OCT-CAP,它能与膜结合的 SNAP 标签相连,并在 UV-A 照射触发时释放 TRPV1 激动剂。通过在表达 TRPV1 的 HEK293T 细胞中进行 Ca2+ 成像和电生理学研究,我们证明了与标准扩散配体或光电笼相比,OCT-CAP 能以更高的时空精度激活 TRPV1。这项研究是首个利用 OCT 配体操纵离子通道靶点的实例。我们预计,这些工具将在控制各种细胞和组织的脂质信号通路中得到广泛应用。
{"title":"Optical Control of TRPV1 Channels <i>In Vitro</i> with Tethered Photopharmacology.","authors":"Carmel L Howe, David Icka-Araki, Alexander E G Viray, Sarahi Garza, James A Frank","doi":"10.1021/acschembio.4c00052","DOIUrl":"https://doi.org/10.1021/acschembio.4c00052","url":null,"abstract":"<p><p>Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel that is important for nociception and inflammatory pain and is activated by a variety of nociceptive stimuli─including lipids such as capsaicin (CAP) and endocannabinoids. TRPV1's role in physiological systems is often studied by activating it with externally perfused ligands; however, this approach is plagued by poor spatiotemporal resolution. Lipid agonists are insoluble in physiological buffers and can permeate membranes to accumulate nonselectively inside cells, where they can have off-target effects. To increase the spatiotemporal precision with which we can activate lipids on cells and tissues, we previously developed optically cleavable targeted (OCT) ligands, which use protein tags (SNAP-tags) to localize a photocaged ligand on a target cellular membrane. After enrichment, the active ligand is released on a flash of light to activate nearby receptors. In our previous work, we developed an OCT-ligand to control a cannabinoid-sensitive GPCR. Here, we expand the scope of OCT-ligand technology to target TRPV1 ion channels. We synthesize a probe, OCT-CAP, that tethers to membrane-bound SNAP-tags and releases a TRPV1 agonist when triggered by UV-A irradiation. Using Ca<sup>2+</sup> imaging and electrophysiology in HEK293T cells expressing TRPV1, we demonstrate that OCT-CAP uncaging activates TRPV1 with superior spatiotemporal precision when compared to standard diffusible ligands or photocages. This study is the first example of an OCT-ligand designed to manipulate an ion-channel target. We anticipate that these tools will find many applications in controlling lipid signaling pathways in various cells and tissues.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.1021/acschembio.4c00174
Sudipta Panja, Rooban B Nahomi, Johanna Rankenberg, Cole R Michel, Ram H Nagaraj
Lysine acetylation (AcK) is a prominent post-translational modification in eye lens crystallins. We have observed that AcK formation is preferred in some lysine residues over others in crystallins. In this study, we have investigated the role of thiols in such AcK formation. Upon incubation with acetyl-CoA (AcCoA), αA-Crystallin, which contains two cysteine residues, showed significantly higher levels of AcK than αB-Crystallin, which lacks cysteine residues. Incubation with thiol-rich γS-Crystallin resulted in higher AcK formation in αB-Crystallin from AcCoA. External free thiol (glutathione and N-acetyl cysteine) increased the AcK content in AcCoA-incubated αB-Crystallin. Reductive alkylation of cysteine residues significantly decreased (p < 0.001) the AcCoA-mediated AcK formation in αA-Crystallin. Introduction of cysteine residues within ∼5 Å of lysine residues (K92C, E99C, and V169C) in αB-Crystallin followed by incubation with AcCoA resulted in a 3.5-, 1.3- and 1.3-fold increase in the AcK levels when compared to wild-type αB-Crystallin, respectively. Together, these results suggested that AcK formation in α-Crystallin is promoted by the proximal cysteine residues and protein-free thiols through an S → N acetyl transfer mechanism.
{"title":"Thiol-Mediated Enhancement of N<sup>ε</sup>-Acetyllysine Formation in Lens Proteins.","authors":"Sudipta Panja, Rooban B Nahomi, Johanna Rankenberg, Cole R Michel, Ram H Nagaraj","doi":"10.1021/acschembio.4c00174","DOIUrl":"https://doi.org/10.1021/acschembio.4c00174","url":null,"abstract":"<p><p>Lysine acetylation (AcK) is a prominent post-translational modification in eye lens crystallins. We have observed that AcK formation is preferred in some lysine residues over others in crystallins. In this study, we have investigated the role of thiols in such AcK formation. Upon incubation with acetyl-CoA (AcCoA), αA-Crystallin, which contains two cysteine residues, showed significantly higher levels of AcK than αB-Crystallin, which lacks cysteine residues. Incubation with thiol-rich γS-Crystallin resulted in higher AcK formation in αB-Crystallin from AcCoA. External free thiol (glutathione and N-acetyl cysteine) increased the AcK content in AcCoA-incubated αB-Crystallin. Reductive alkylation of cysteine residues significantly decreased (<i>p</i> < 0.001) the AcCoA-mediated AcK formation in αA-Crystallin. Introduction of cysteine residues within ∼5 Å of lysine residues (K92C, E99C, and V169C) in αB-Crystallin followed by incubation with AcCoA resulted in a 3.5-, 1.3- and 1.3-fold increase in the AcK levels when compared to wild-type αB-Crystallin, respectively. Together, these results suggested that AcK formation in α-Crystallin is promoted by the proximal cysteine residues and protein-free thiols through an S → N acetyl transfer mechanism.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The precise spatial and temporal orchestration of gene expression is crucial for the ontogeny of an organism and is mainly governed by transcription factors (TFs). The mechanism of recognition of cognate sites amid millions of base pairs in the genome by TFs is still incompletely understood. In this study, we focus on DNA sequence composition, shape, and flexibility preferences of 28 quintessential TFs from Drosophila melanogaster that are critical to development and body patterning mechanisms. Our study finds that TFs exhibit distinct predilections for DNA shape, flexibility, and sequence compositions in the proximity of transcription factor binding sites (TFBSs). Notably, certain zinc finger proteins prefer GC-rich areas with less negative propeller twist, while homeodomains mainly seek AT-rich regions with a more negative propeller twist at their sites. Intriguingly, while numerous cofactors share similar binding site preferences and bind closer to each other in the genome, some cofactors that have different preferences bind farther apart. These findings shed light on TF DNA recognition and provide novel insights into possible cofactor binding and transcriptional regulation mechanisms.
基因表达在空间和时间上的精确协调对生物体的本体发育至关重要,主要由转录因子(TFs)控制。转录因子识别基因组中数百万个碱基对中的同源位点的机制尚未完全明了。在这项研究中,我们重点研究了黑腹果蝇中对发育和身体模式化机制至关重要的 28 种典型 TFs 的 DNA 序列组成、形状和灵活性偏好。我们的研究发现,在转录因子结合位点(TFBS)附近,转录因子对 DNA 的形状、灵活性和序列组成表现出不同的偏好。值得注意的是,某些锌指蛋白偏好负螺旋桨扭转较小的富含 GC 的区域,而同源结构域主要寻找富含 AT 的区域,其结合位点的负螺旋桨扭转较大。耐人寻味的是,虽然许多辅助因子具有相似的结合位点偏好,并且在基因组中彼此结合得较近,但一些具有不同偏好的辅助因子却结合得较远。这些发现揭示了 TF DNA 的识别,并为可能的辅助因子结合和转录调控机制提供了新的见解。
{"title":"Discerning the Role of DNA Sequence, Shape, and Flexibility in Recognition by <i>Drosophila</i> Transcription Factors.","authors":"Smrithi Murthy, Upalabdha Dey, Kaushika Olymon, Eshan Abbas, Venkata Rajesh Yella, Aditya Kumar","doi":"10.1021/acschembio.4c00202","DOIUrl":"https://doi.org/10.1021/acschembio.4c00202","url":null,"abstract":"<p><p>The precise spatial and temporal orchestration of gene expression is crucial for the ontogeny of an organism and is mainly governed by transcription factors (TFs). The mechanism of recognition of cognate sites amid millions of base pairs in the genome by TFs is still incompletely understood. In this study, we focus on DNA sequence composition, shape, and flexibility preferences of 28 quintessential TFs from <i>Drosophila melanogaster</i> that are critical to development and body patterning mechanisms. Our study finds that TFs exhibit distinct predilections for DNA shape, flexibility, and sequence compositions in the proximity of transcription factor binding sites (TFBSs). Notably, certain zinc finger proteins prefer GC-rich areas with less negative propeller twist, while homeodomains mainly seek AT-rich regions with a more negative propeller twist at their sites. Intriguingly, while numerous cofactors share similar binding site preferences and bind closer to each other in the genome, some cofactors that have different preferences bind farther apart. These findings shed light on TF DNA recognition and provide novel insights into possible cofactor binding and transcriptional regulation mechanisms.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peptide-bile acid hybrids offer promising drug candidates due to enhanced pharmacological properties, such as improved protease resistance and oral bioavailability. However, it remains unknown whether bile acids can be incorporated into peptide chains by the ribosome to produce a peptide-bile acid hybrid macrocyclic peptide library for target-based de novo screening. In this study, we achieved the ribosomal incorporation of lithocholic acid (LCA)-d-tyrosine into peptide chains. This led to the construction of a peptide-LCA hybrid macrocyclic peptide library, which enabled the identification of peptides TP-2C-4L3 (targeting Trop2) and EP-2C-4L5 (targeting EphA2) with strong binding affinities. Notably, LCA was found to directly participate in binding to EphA2 and confer on the peptides improved stability and resistance to proteases. Cell staining experiments confirmed the high specificity of the peptides for targeting Trop2 and EphA2. This study highlights the benefits of LCA in peptides and paves the way for de novo discovery of stable peptide-LCA hybrid drugs.
{"title":"Ribosomal Incorporation of Lithocholic Acid into Peptides for the <i>De Novo</i> Discovery Of Peptide-Lithocholic Acid Hybrid Macrocyclic Peptides.","authors":"Lulu Song, Hongtan Liu, Maolin Li, Yawen Yang, Huilei Dong, Jinjing Li, Jiaqi Shao, Lixu Zhi, Hao Sun, Zhifeng Li, Haiyan Sui, Youming Zhang, Chuanliu Wu, Yizhen Yin","doi":"10.1021/acschembio.4c00298","DOIUrl":"https://doi.org/10.1021/acschembio.4c00298","url":null,"abstract":"<p><p>Peptide-bile acid hybrids offer promising drug candidates due to enhanced pharmacological properties, such as improved protease resistance and oral bioavailability. However, it remains unknown whether bile acids can be incorporated into peptide chains by the ribosome to produce a peptide-bile acid hybrid macrocyclic peptide library for target-based <i>de novo</i> screening. In this study, we achieved the ribosomal incorporation of lithocholic acid (LCA)-d-tyrosine into peptide chains. This led to the construction of a peptide-LCA hybrid macrocyclic peptide library, which enabled the identification of peptides TP-2C-4L3 (targeting Trop2) and EP-2C-4L5 (targeting EphA2) with strong binding affinities. Notably, LCA was found to directly participate in binding to EphA2 and confer on the peptides improved stability and resistance to proteases. Cell staining experiments confirmed the high specificity of the peptides for targeting Trop2 and EphA2. This study highlights the benefits of LCA in peptides and paves the way for <i>de novo</i> discovery of stable peptide-LCA hybrid drugs.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}