{"title":"电位滴定法研究配体与 DNA i-motifs 的相互作用。","authors":"Joseph Boissieras, Anton Granzhan","doi":"10.1016/bs.mie.2023.11.005","DOIUrl":null,"url":null,"abstract":"<p><p>i-Motifs are non-canonical secondary structures of DNA formed by mutual intercalation of hemi-protonated cytosine-cytosine base pairs, most typically in slightly acidic conditions (pH<7.0). These structures are well-studied in vitro and have recently been suggested to exist in cells. Despite nearly a decade of active research, the quest for small-molecule ligands that could selectively bind to and stabilize i-motifs continues, and no reference, bona fide i-motif ligand is currently available. This is, at least in part, due to the lack of robust methods to assess the interaction of ligands with i-motifs, since many techniques well-established for studies of other secondary structures (such as CD-, UV-, and FRET-melting) may generate artifacts when applied to i-motifs. Here, we describe an implementation of automated, potentiometric (pH) titrations as a robust isothermal method to assess the impact of ligands or cosolutes on thermodynamic stability of i-motifs. This approach is validated through the use of a cosolute previously known to stabilize i-motifs (PEG2000) and three small-molecule ligands that are able to stabilize, destabilize, or have no effect on the stability of i-motifs, respectively.</p>","PeriodicalId":18662,"journal":{"name":"Methods in enzymology","volume":"695 ","pages":"233-254"},"PeriodicalIF":0.0000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Potentiometric titrations to study ligand interactions with DNA i-motifs.\",\"authors\":\"Joseph Boissieras, Anton Granzhan\",\"doi\":\"10.1016/bs.mie.2023.11.005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>i-Motifs are non-canonical secondary structures of DNA formed by mutual intercalation of hemi-protonated cytosine-cytosine base pairs, most typically in slightly acidic conditions (pH<7.0). These structures are well-studied in vitro and have recently been suggested to exist in cells. Despite nearly a decade of active research, the quest for small-molecule ligands that could selectively bind to and stabilize i-motifs continues, and no reference, bona fide i-motif ligand is currently available. This is, at least in part, due to the lack of robust methods to assess the interaction of ligands with i-motifs, since many techniques well-established for studies of other secondary structures (such as CD-, UV-, and FRET-melting) may generate artifacts when applied to i-motifs. Here, we describe an implementation of automated, potentiometric (pH) titrations as a robust isothermal method to assess the impact of ligands or cosolutes on thermodynamic stability of i-motifs. This approach is validated through the use of a cosolute previously known to stabilize i-motifs (PEG2000) and three small-molecule ligands that are able to stabilize, destabilize, or have no effect on the stability of i-motifs, respectively.</p>\",\"PeriodicalId\":18662,\"journal\":{\"name\":\"Methods in enzymology\",\"volume\":\"695 \",\"pages\":\"233-254\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Methods in enzymology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1016/bs.mie.2023.11.005\",\"RegionNum\":4,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2023/12/4 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"Biochemistry, Genetics and Molecular Biology\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Methods in enzymology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/bs.mie.2023.11.005","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/12/4 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"Biochemistry, Genetics and Molecular Biology","Score":null,"Total":0}
引用次数: 0
摘要
i-Motifs 是半质子化胞嘧啶-胞嘧啶碱基对相互插层形成的 DNA 非规范二级结构,最典型的情况是在微酸性条件下(pH 值为 1.5)。
Potentiometric titrations to study ligand interactions with DNA i-motifs.
i-Motifs are non-canonical secondary structures of DNA formed by mutual intercalation of hemi-protonated cytosine-cytosine base pairs, most typically in slightly acidic conditions (pH<7.0). These structures are well-studied in vitro and have recently been suggested to exist in cells. Despite nearly a decade of active research, the quest for small-molecule ligands that could selectively bind to and stabilize i-motifs continues, and no reference, bona fide i-motif ligand is currently available. This is, at least in part, due to the lack of robust methods to assess the interaction of ligands with i-motifs, since many techniques well-established for studies of other secondary structures (such as CD-, UV-, and FRET-melting) may generate artifacts when applied to i-motifs. Here, we describe an implementation of automated, potentiometric (pH) titrations as a robust isothermal method to assess the impact of ligands or cosolutes on thermodynamic stability of i-motifs. This approach is validated through the use of a cosolute previously known to stabilize i-motifs (PEG2000) and three small-molecule ligands that are able to stabilize, destabilize, or have no effect on the stability of i-motifs, respectively.
期刊介绍:
The critically acclaimed laboratory standard for almost 50 years, Methods in Enzymology is one of the most highly respected publications in the field of biochemistry. Each volume is eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now with over 500 volumes the series contains much material still relevant today and is truly an essential publication for researchers in all fields of life sciences, including microbiology, biochemistry, cancer research and genetics-just to name a few. Five of the 2013 Nobel Laureates have edited or contributed to volumes of MIE.