Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-03-08DOI: 10.1016/bs.mie.2025.01.003
Reilly Q Mach, Shannon M Miller
{"title":"Bacterial directed evolution of CRISPR base editors.","authors":"Reilly Q Mach, Shannon M Miller","doi":"10.1016/bs.mie.2025.01.003","DOIUrl":"10.1016/bs.mie.2025.01.003","url":null,"abstract":"<p><p>Base editing and other precision editing agents have transformed the utility and therapeutic potential of CRISPR-based genome editing. While some native enzymes edit efficiently with their nature-derived function, many enzymes require rational engineering or directed evolution to enhance the compatibility with mammalian cell genome editing. While many methods of engineering and directed evolution exist, plate-based discrete evolution offers an ideal balance between ease of use and engineering power. Here, we describe a detailed method for the bacterial directed evolution of CRISPR base editors that compounds technical ease with flexibility of application.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"712 ","pages":"317-350"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692751","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-01-02DOI: 10.1016/bs.mie.2024.11.033
Emma Lamb, Dyuti Pant, Boyoon Yang, Heather A Hundley
{"title":"A probe-based capture enrichment method for detection of A-to-I editing in low abundance transcripts.","authors":"Emma Lamb, Dyuti Pant, Boyoon Yang, Heather A Hundley","doi":"10.1016/bs.mie.2024.11.033","DOIUrl":"10.1016/bs.mie.2024.11.033","url":null,"abstract":"<p><p>Exactly two decades ago, the ability to use high-throughput RNA sequencing technology to identify sites of editing by ADARs was employed for the first time. Since that time, RNA sequencing has become a standard tool for researchers studying RNA biology and led to the discovery of RNA editing sites present in a multitude of organisms, across tissue types, and in disease. However, transcriptome-wide sequencing is not without limitations. Most notably, RNA sequencing depth of a given transcript is correlated with expression, and sequencing depth impacts the ability to robustly detect RNA editing events. This chapter focuses on a method for enrichment of low-abundance transcripts that can facilitate more efficient sequencing and detection of RNA editing events. An important note is that while we describe aspects of the protocol important for capturing intron-containing transcripts, this probe-based enrichment method could be easily modified to assess editing within any low-abundance transcript. We also provide some perspectives on the current limitations as well as important future directions for expanding this technology to gain more insights into how RNA editing can impact transcript diversity.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"710 ","pages":"55-75"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143052974","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-01-02DOI: 10.1016/bs.mie.2024.11.032
Alla Fishman, Ayelet T Lamm
{"title":"Obstacles in quantifying A-to-I RNA editing by Sanger sequencing.","authors":"Alla Fishman, Ayelet T Lamm","doi":"10.1016/bs.mie.2024.11.032","DOIUrl":"10.1016/bs.mie.2024.11.032","url":null,"abstract":"<p><p>Adenosine-to-Inosine (A-to-I) RNA editing is the most prevalent type of RNA editing, in which adenosine within a completely or largely double-stranded RNA (dsRNA) is converted to inosine by deamination. RNA editing was shown to be involved in many neurological diseases and cancer; therefore, detection of A-to-I RNA editing and quantitation of editing levels are necessary for both basic and clinical biomedical research. While high-throughput sequencing (HTS) is widely used for global detection of editing events, Sanger sequencing is the method of choice for precise characterization of editing site clusters (hyper-editing) and for comparing levels of editing at a particular site under different environmental conditions, developmental stages, genetic backgrounds, or disease states. To detect A-to-I editing events and quantify them using Sanger sequencing, RNA samples are reverse transcribed, cDNA is amplified using gene-specific primers, and then sequenced. The chromatogram outputs are then compared to the genomic DNA sequence. As editing occurs in the context of dsRNA, the reverse transcription step is performed at a temperature as high as 65 °C, using thermostable reverse transcriptase to open double-stranded structures. However, this measure alone is insufficient for transcripts possessing long stems comprised of hundreds of nucleotide pairs. Consequently, the editing levels detected by Sanger sequencing are significantly lower than those obtained by HTS, and the amplification yield is low. We suggest that the reverse transcription is biased towards unedited transcripts, and the severity of the bias is dependent on the transcript's secondary structure. Here, we show how this bias can be significantly reduced to allow reliable detection of editing levels and sufficient product yield.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"710 ","pages":"285-302"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143052991","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-03-06DOI: 10.1016/bs.mie.2025.01.033
Zi-Xian Liu, Jun-Jie Gogo Liu
{"title":"Hydrolytic endonucleolytic ribozyme (HYER): Systematic identification, characterization and potential application in nucleic acid manipulation.","authors":"Zi-Xian Liu, Jun-Jie Gogo Liu","doi":"10.1016/bs.mie.2025.01.033","DOIUrl":"10.1016/bs.mie.2025.01.033","url":null,"abstract":"<p><p>Group II introns are transposable elements that can propagate in host genomes through the \"copy and paste\" mechanism. They usually comprise RNA and protein components for effective propagation. Recently, we found that some bacterial GII-C introns without protein components had multiple copies in their resident genomes, implicating their potential transposition activity. We demonstrated that some of these systems are active for hydrolytic DNA cleavage and proved their DNA manipulation capability in bacterial or mammalian cells. These introns are therefore named HYdrolytic Endonucleolytic Ribozymes (HYERs). Here, we provide a detailed protocol for the systematic identification and characterization of HYERs and present our perspectives on its potential application in nucleic acid manipulation.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"712 ","pages":"197-223"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692803","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-02-25DOI: 10.1016/bs.mie.2025.01.080
Dirk Tischler, Giovanni Davide Barone, Jose Munoz-Munoz, John M Woodley
{"title":"Biocatalysis: Important considerations for testing and evaluation of biocatalysts.","authors":"Dirk Tischler, Giovanni Davide Barone, Jose Munoz-Munoz, John M Woodley","doi":"10.1016/bs.mie.2025.01.080","DOIUrl":"10.1016/bs.mie.2025.01.080","url":null,"abstract":"<p><p>Selecting the appropriate mode of biocatalysis application is crucial for optimizing efficiency and sustainability. This chapter provides a comprehensive guide on key metrics to describe biocatalyst performance, including kinetic parameters such as reaction rates, cofactor requirements, dissociation constants (K<sub>D</sub>), maximum velocities (V<sub>max</sub>), turnover numbers (k<sub>cat</sub>), and Michaelis constants (K<sub>M</sub>). Additionally, it discusses biocatalysis metrics like turnover frequency (TOF), environmental factors (E-Factor), atom economy, productivities, and Life Cycle Assessment (LCA). The chapter also explores application types, focusing on whole-cell and cell-free enzyme applications, and offers a practical guide on selecting the most suitable mode of application based on specific project requirements. By integrating these considerations, researchers can effectively harness biocatalysis for innovative and sustainable solutions in various industrial processes.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"714 ","pages":"1-17"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144032987","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-02-06DOI: 10.1016/bs.mie.2025.01.065
Kamyar Zahedi, Sharon Barone, Manoocher Soleimani
{"title":"Evaluation of platinum drug toxicity resulting from polyamine catabolism.","authors":"Kamyar Zahedi, Sharon Barone, Manoocher Soleimani","doi":"10.1016/bs.mie.2025.01.065","DOIUrl":"https://doi.org/10.1016/bs.mie.2025.01.065","url":null,"abstract":"<p><p>Polyamines, spermidine (Spd) and Spermine (Spm), are polycations that serve a number of important biological functions. The tissue contents of polyamines are tightly regulated through their cellular import and export, as well as their metabolism (anabolism and catabolism). Polyamine catabolism in mediated via the spermidine/spermine N1-acetyltransferase (SAT1)/acetylpolyamine oxidase (APOX) cascade and oxidation of Spm by spermine oxidase (SMOX). The expression of SAT1 and SMOX increases in injured organs in response to trauma, ischemia/reperfusion, sepsis, and exposure to toxic compounds. Cisplatin is a highly effective chemotherapeutic agent that is used for the treatment of a variety of solid tumors. Its anti-tumor activity is mediated via its ability to form stable DNA adducts that inhibit the growth of actively proliferating cells. However, cisplatin also can lead to severe off-target deleterious effects (e.g., nephrotoxicity and ototoxicity), and because of such adverse effects the use of cisplatin has to be discontinued in many patients. Understanding and decoupling the therapeutic and toxic effects of cisplatin will lead to more effective use of this and other platinum-derived compounds in the treatment of cancer patients. Acute and chronic exposure to cisplatin in mice leads to severe renal tubular injuries and an increase in the expression of SAT1 and SMOX while the ablation of their genes in mice reduces the severity of nephrotoxic injuries caused by cisplatin. Furthermore, neutralization of the toxic by-products of polyamine degradation reduce the severity if cisplatin nephrotoxicity. These observations suggest that interventions targeting the adverse effects of enhanced polyamine catabolism may provide effective therapies by reducing the toxic effects of cisplatin without affecting its anti-neoplastic activity.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"715 ","pages":"93-116"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094196","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":"Preface.","authors":"Robert A Casero, Tracy Murray Stewart","doi":"10.1016/S0076-6879(25)00204-6","DOIUrl":"https://doi.org/10.1016/S0076-6879(25)00204-6","url":null,"abstract":"","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"715 ","pages":"xxix-xxx"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144094325","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-02-16DOI: 10.1016/bs.mie.2025.01.055
Timothy D H Bugg, Mark Ahmad, Charles R Taylor, Marina Konstantopoulou, Goran M M Rashid
{"title":"Assay methods and colorimetric screens for lignin-degrading microbes and lignin-oxidising enzymes.","authors":"Timothy D H Bugg, Mark Ahmad, Charles R Taylor, Marina Konstantopoulou, Goran M M Rashid","doi":"10.1016/bs.mie.2025.01.055","DOIUrl":"https://doi.org/10.1016/bs.mie.2025.01.055","url":null,"abstract":"<p><p>Assaying enzymes and microbes for activity for degradation of polymeric lignin is inherently challenging to do. This article describes several methods that our research group has developed for assay of lignin-oxidising enzymes and lignin-degrading microbes. The assay methods involve (1) colorimetric assays involving chemically nitrated lignin; (2) changes in molecular weight using gel filtration chromatography; (3) delignification of lignocellulose using Klason assay; (4) colorimetric assays for release of low molecular weight phenols and carbonyl compounds.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"716 ","pages":"105-123"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294053","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}
Methods in enzymologyPub Date : 2025-01-01Epub Date: 2025-03-18DOI: 10.1016/bs.mie.2025.01.044
Lucas F Ribeiro, Gilvan P Furtado, Marcos R Lourenzoni, Richard J Ward
{"title":"Design, construction and characterization of laccase-xylanase chimeras by insertional fusion.","authors":"Lucas F Ribeiro, Gilvan P Furtado, Marcos R Lourenzoni, Richard J Ward","doi":"10.1016/bs.mie.2025.01.044","DOIUrl":"https://doi.org/10.1016/bs.mie.2025.01.044","url":null,"abstract":"<p><p>The broad substrate specificity of laccases makes these enzymes suitable for a wide range of applications. The use of protein engineering strategies to modulate the catalytic properties of these enzymes is a promising strategy to expand their use in the sustainable economy. Here we describe the construction of laccase-xylanase bifunctional enzyme by insertional fusion using a procedure based on the rational design starting with the analysis of the 3D-structure of laccase to select positions for the insertion of the xylanase domain, followed by the creation of the fusion construct by ligation of overlapping fragments generated by PCR. Finally, the heterologous expression and biochemical characterization of the laccase and xylanase activities of the fusion protein is described and demonstrate significant increase in the laccase activity. These protocols can be applied to the fusion of any pair of proteins.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"716 ","pages":"217-238"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294056","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":"Preface.","authors":"Timothy Bugg, Juan Carro","doi":"10.1016/S0076-6879(25)00251-4","DOIUrl":"https://doi.org/10.1016/S0076-6879(25)00251-4","url":null,"abstract":"","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"716 ","pages":"xix-xx"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294091","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}