Nihar Pradeep Khandave , Ved Prakash Tiwari , Pramodh Vallurupalli
{"title":"使用酰胺15N CEST核磁共振实验研究“可见”蛋白质状态之间的缓慢交换","authors":"Nihar Pradeep Khandave , Ved Prakash Tiwari , Pramodh Vallurupalli","doi":"10.1016/j.jmr.2025.107883","DOIUrl":null,"url":null,"abstract":"<div><div>Slow exchange between ‘visible’ protein states is often studied using the two-dimensional ZZ exchange class of magnetisation transfer experiments. However, the cross-peaks that arise due to magnetisation transfer between different states can lead to additional overlap in the two-dimensional ZZ exchange NMR spectrum. To overcome this overlap problem, here we have explored the utility of the <sup>15</sup>N CEST experiment as an alternative to the <sup>1</sup>H<sup>N</sup>–<sup>15</sup>N ZZ exchange experiment to study exchange between ‘visible’ protein states. In the case of two-state exchange, the <sup>1</sup>H<sup>N</sup>–<sup>15</sup>N correlation map contains two correlations for each exchanging site, one arising from each state. Thus, two <sup>15</sup>N CEST profiles can be recorded for each of these sites using a single <sup>15</sup>N CEST experiment. We find that site-specific exchange parameters can then be obtained by simultaneously analysing both these <sup>15</sup>N CEST profiles recorded at a single ‘high’ <em>B</em><sub><em>1</em></sub> field supplemented with experimentally derived information regarding the initial magnetisation or as in the case of the ZZ exchange experiment, the minor state population. The utility of the <sup>15</sup>N CEST based approach to characterise exchange between visible protein states is demonstrated by studying the interconversion of the ∼18 kDa T34A mutant of T4 lysozyme between its native state and a minor state populated to ∼21 % (exchange rate ∼5 s<sup>−1</sup>) at 40 °C.</div></div>","PeriodicalId":16267,"journal":{"name":"Journal of magnetic resonance","volume":"375 ","pages":"Article 107883"},"PeriodicalIF":1.9000,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Using the amide 15N CEST NMR experiment to study slow exchange between ‘visible’ protein states\",\"authors\":\"Nihar Pradeep Khandave , Ved Prakash Tiwari , Pramodh Vallurupalli\",\"doi\":\"10.1016/j.jmr.2025.107883\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Slow exchange between ‘visible’ protein states is often studied using the two-dimensional ZZ exchange class of magnetisation transfer experiments. However, the cross-peaks that arise due to magnetisation transfer between different states can lead to additional overlap in the two-dimensional ZZ exchange NMR spectrum. To overcome this overlap problem, here we have explored the utility of the <sup>15</sup>N CEST experiment as an alternative to the <sup>1</sup>H<sup>N</sup>–<sup>15</sup>N ZZ exchange experiment to study exchange between ‘visible’ protein states. In the case of two-state exchange, the <sup>1</sup>H<sup>N</sup>–<sup>15</sup>N correlation map contains two correlations for each exchanging site, one arising from each state. Thus, two <sup>15</sup>N CEST profiles can be recorded for each of these sites using a single <sup>15</sup>N CEST experiment. We find that site-specific exchange parameters can then be obtained by simultaneously analysing both these <sup>15</sup>N CEST profiles recorded at a single ‘high’ <em>B</em><sub><em>1</em></sub> field supplemented with experimentally derived information regarding the initial magnetisation or as in the case of the ZZ exchange experiment, the minor state population. The utility of the <sup>15</sup>N CEST based approach to characterise exchange between visible protein states is demonstrated by studying the interconversion of the ∼18 kDa T34A mutant of T4 lysozyme between its native state and a minor state populated to ∼21 % (exchange rate ∼5 s<sup>−1</sup>) at 40 °C.</div></div>\",\"PeriodicalId\":16267,\"journal\":{\"name\":\"Journal of magnetic resonance\",\"volume\":\"375 \",\"pages\":\"Article 107883\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2025-04-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of magnetic resonance\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1090780725000552\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOCHEMICAL RESEARCH METHODS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of magnetic resonance","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1090780725000552","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
Using the amide 15N CEST NMR experiment to study slow exchange between ‘visible’ protein states
Slow exchange between ‘visible’ protein states is often studied using the two-dimensional ZZ exchange class of magnetisation transfer experiments. However, the cross-peaks that arise due to magnetisation transfer between different states can lead to additional overlap in the two-dimensional ZZ exchange NMR spectrum. To overcome this overlap problem, here we have explored the utility of the 15N CEST experiment as an alternative to the 1HN–15N ZZ exchange experiment to study exchange between ‘visible’ protein states. In the case of two-state exchange, the 1HN–15N correlation map contains two correlations for each exchanging site, one arising from each state. Thus, two 15N CEST profiles can be recorded for each of these sites using a single 15N CEST experiment. We find that site-specific exchange parameters can then be obtained by simultaneously analysing both these 15N CEST profiles recorded at a single ‘high’ B1 field supplemented with experimentally derived information regarding the initial magnetisation or as in the case of the ZZ exchange experiment, the minor state population. The utility of the 15N CEST based approach to characterise exchange between visible protein states is demonstrated by studying the interconversion of the ∼18 kDa T34A mutant of T4 lysozyme between its native state and a minor state populated to ∼21 % (exchange rate ∼5 s−1) at 40 °C.
期刊介绍:
The Journal of Magnetic Resonance presents original technical and scientific papers in all aspects of magnetic resonance, including nuclear magnetic resonance spectroscopy (NMR) of solids and liquids, electron spin/paramagnetic resonance (EPR), in vivo magnetic resonance imaging (MRI) and spectroscopy (MRS), nuclear quadrupole resonance (NQR) and magnetic resonance phenomena at nearly zero fields or in combination with optics. The Journal''s main aims include deepening the physical principles underlying all these spectroscopies, publishing significant theoretical and experimental results leading to spectral and spatial progress in these areas, and opening new MR-based applications in chemistry, biology and medicine. The Journal also seeks descriptions of novel apparatuses, new experimental protocols, and new procedures of data analysis and interpretation - including computational and quantum-mechanical methods - capable of advancing MR spectroscopy and imaging.