{"title":"Assessing the applicability of 19F labeled tryptophan residues to quantify protein dynamics","authors":"Christina Krempl, Remco Sprangers","doi":"10.1007/s10858-022-00411-2","DOIUrl":"10.1007/s10858-022-00411-2","url":null,"abstract":"<div><p>Nuclear magnetic resonance (NMR) spectroscopy is uniquely suited to study the dynamics of biomolecules in solution. Most NMR studies exploit the spins of proton, carbon and nitrogen isotopes, as these atoms are highly abundant in proteins and nucleic acids. As an alternative and complementary approach, fluorine atoms can be introduced into biomolecules at specific sites of interest. These labels can then be used as sensitive probes for biomolecular structure, dynamics or interactions. Here, we address if the replacement of tryptophan with 5-fluorotryptophan residues has an effect on the overall dynamics of proteins and if the introduced fluorine probe is able to accurately report on global exchange processes. For the four different model proteins (KIX, Dcp1, Dcp2 and DcpS) that we examined, we established that <sup>15</sup>N CPMG relaxation dispersion or EXSY profiles are not affected by the 5-fluorotryptophan, indicating that this replacement of a proton with a fluorine has no effect on the protein motions. However, we found that the motions that the 5-fluorotryptophan reports on can be significantly faster than the backbone motions. This implies that care needs to be taken when interpreting fluorine relaxation data in terms of global protein motions. In summary, our results underscore the great potential of fluorine NMR methods, but also highlight potential pitfalls that need to be considered.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00411-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4572563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephan B. Azatian, Marella D. Canny, Michael P. Latham
{"title":"Three segment ligation of a 104 kDa multi-domain protein by SrtA and OaAEP1","authors":"Stephan B. Azatian, Marella D. Canny, Michael P. Latham","doi":"10.1007/s10858-022-00409-w","DOIUrl":"10.1007/s10858-022-00409-w","url":null,"abstract":"<div><p>NMR spectroscopy is an excellent tool for studying protein structure and dynamics which provides a deeper understanding of biological function. As the size of the biomolecule of interest increases, it can become advantageous to dilute the number of observed signals in the NMR spectrum to decrease spectral overlap and increase resolution. One way to limit the number of resonances in the NMR data is by selectively labeling a smaller domain within the larger macromolecule, a process called segmental isotopic labeling. Many examples of segmental isotopic labeling have been described where two segments of a protein are ligated together by chemical or enzymatic means, but there are far fewer descriptions of a three or more segment ligation reaction. Herein, we describe an enzymatic segmental labeling scheme that combines the widely used Sortase A and more recently described OaAEP1 for a two site ligation strategy. In preparation to study proposed long-range allostery in the 104 kDa DNA damage repair protein Rad50, we ligated side-chain methyl group labeled Zn Hook domain between two long segments of otherwise unlabeled <i>P.furiosus</i> Rad50. Enzymatic activity data demonstrated that the scars resulting from the ligation reactions did not affect Rad50 function within the Mre11-Rad50 DNA double strand break repair complex. Finally, methyl-based NMR spectroscopy confirmed the formation of the full-length ligated protein. Our strategy highlights the strengths of OaAEP1 for segmental labeling, namely faster reaction times and a smaller recognition sequence, and provides a straightforward template for using these two enzymes in multisite segmental labeling reactions.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00409-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4814291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Water irradiation devoid pulses enhance the sensitivity of 1H,1H nuclear Overhauser effects","authors":"V. S. Manu, Cristina Olivieri, Gianluigi Veglia","doi":"10.1007/s10858-022-00407-y","DOIUrl":"10.1007/s10858-022-00407-y","url":null,"abstract":"<div><p>The nuclear Overhauser effect (NOE) is one of NMR spectroscopy's most important and versatile parameters. NOE is routinely utilized to determine the structures of medium-to-large size biomolecules and characterize protein–protein, protein–RNA, protein–DNA, and protein–ligand interactions in aqueous solutions. Typical [<sup>1</sup>H,<sup>1</sup>H] NOESY pulse sequences incorporate water suppression schemes to reduce the water signal that dominates <sup>1</sup>H-detected spectra and minimize NOE intensity losses due to unwanted polarization exchange between water and labile protons. However, at high- and ultra-high magnetic fields, the excitation of the water signal during the execution of the NOESY pulse sequences may cause significant attenuation of NOE cross-peak intensities. Using an evolutionary algorithm coupled with artificial intelligence, we recently designed high-fidelity pulses [<i>W</i>ater irr<i>A</i>diation <i>DE</i>void (WADE) pulses] that elude water excitation and irradiate broader bandwidths relative to commonly used pulses. Here, we demonstrate that WADE pulses, implemented into the 2D [<sup>1</sup>H,<sup>1</sup>H] NOESY experiments, increase the intensity of the NOE cross-peaks for labile and, to a lesser extent, non-exchangeable protons. We applied the new 2D [<sup>1</sup>H,<sup>1</sup>H] WADE-NOESY pulse sequence to two well-folded, medium-size proteins, i.e., the K48C mutant of ubiquitin and the Raf kinase inhibitor protein. We observed a net increase of the NOE intensities varying from 30 to 170% compared to the commonly used NOESY experiments. The new WADE pulses can be easily engineered into 2D and 3D homo- and hetero-nuclear NOESY pulse sequences to boost their sensitivity.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4745842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chen Peng, Andrew T. Namanja, Eva Munoz, Haihong Wu, Thomas E. Frederick, Mitcheell Maestre-Martinez, Isaac Iglesias Fernandez, Qi Sun, Carlos Cobas, Chaohong Sun, Andrew M. Petros
{"title":"Efficiently driving protein-based fragment screening and lead discovery using two-dimensional NMR","authors":"Chen Peng, Andrew T. Namanja, Eva Munoz, Haihong Wu, Thomas E. Frederick, Mitcheell Maestre-Martinez, Isaac Iglesias Fernandez, Qi Sun, Carlos Cobas, Chaohong Sun, Andrew M. Petros","doi":"10.1007/s10858-022-00410-3","DOIUrl":"10.1007/s10858-022-00410-3","url":null,"abstract":"<div><p>Fragment-based drug discovery (FBDD) and validation of small molecule binders using NMR spectroscopy is an established and widely used method in the early stages of drug discovery. Starting from a library of small compounds, ligand- or protein-observed NMR methods are employed to detect binders, typically weak, that become the starting points for structure–activity relationships (SAR) by NMR. Unlike the more frequently used ligand-observed 1D NMR techniques, protein-observed 2D <sup>1</sup>H-<sup>15</sup>N or <sup>1</sup>H-<sup>13</sup>C heteronuclear correlation (HSQC or HMQC) methods offer insights that include the mechanism of ligand engagement on the target and direct binding affinity measurements in addition to routine screening. We hereby present the development of a set of software tools within the MestReNova (Mnova) package for analyzing 2D NMR for FBDD and hit validation purposes. The package covers three main tasks: (1) unsupervised profiling of raw data to identify outlier data points to exclude in subsequent analyses; (2) batch processing of single-point spectra to identify and rank binders based on chemical shift perturbations or spectral peak intensity changes; and (3) batch processing of multiple titration series to derive binding affinities (<i>K</i><sub>D</sub>) by tracing the changes in peak locations or measuring global spectral changes. Toward this end, we implemented and evaluated a set of algorithms for automated peak tracing, spectral binning, and variance analysis by PCA, and a new tool for spectral data intensity comparison using ECHOS. The accuracy and speed of the tools are demonstrated on 2D NMR binding data collected on ligands used in the development of potential inhibitors of the anti-apoptotic MCL-1 protein.</p><h3>Graphical abstract</h3>\u0000 <figure><div><div><div><picture><source><img></source></picture></div></div></div></figure>\u0000 </div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00410-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4526950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vladislav V. Motov, Erik F. Kot, Alexandra V. Shabalkina, Sergey A. Goncharuk, Alexander S. Arseniev, Marina V. Goncharuk, Konstantin S. Mineev
{"title":"Investigation of lipid/protein interactions in trifluoroethanol-water mixtures proposes the strategy for the refolding of helical transmembrane domains","authors":"Vladislav V. Motov, Erik F. Kot, Alexandra V. Shabalkina, Sergey A. Goncharuk, Alexander S. Arseniev, Marina V. Goncharuk, Konstantin S. Mineev","doi":"10.1007/s10858-022-00408-x","DOIUrl":"10.1007/s10858-022-00408-x","url":null,"abstract":"<div><p>Membrane proteins are one of the keystone objects in molecular biology, but their structural studies often require an extensive search for an appropriate membrane-like environment and an efficient refolding protocol for a recombinant protein. Isotropic bicelles are a convenient membrane mimetic used in structural studies of membrane proteins. Helical membrane domains are often transferred into bicelles from trifluoroethanol–water mixtures. However, the protocols for such a refolding are empirical and the process itself is still not understood in detail. In search of the optimal refolding approaches for helical membrane proteins, we studied here how membrane proteins, lipids, and detergents interact with each other at various trifluoroethanol–water ratios. Using high-resolution NMR spectroscopy and dynamic light scattering, we determined the key states of the listed compounds in the trifluoroethanol/water mixture, found the factors that could be critical for the efficiency of refolding, and proposed several most optimal protocols. These protocols were developed on the transmembrane domain of neurotrophin receptor TrkA and tested on two model helical membrane domains—transmembrane of Toll-like receptor TLR9 and voltage-sensing domain of a potassium channel KvAP.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5164133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stella Slad, Wolfgang Bermel, Rainer Kümmerle, Daniel Mathieu, Burkhard Luy
{"title":"Band-selective universal 90° and 180° rotation pulses covering the aliphatic carbon chemical shift range for triple resonance experiments on 1.2 GHz spectrometers","authors":"Stella Slad, Wolfgang Bermel, Rainer Kümmerle, Daniel Mathieu, Burkhard Luy","doi":"10.1007/s10858-022-00404-1","DOIUrl":"10.1007/s10858-022-00404-1","url":null,"abstract":"<div><p>Biomolecular NMR spectroscopy requires large magnetic field strengths for high spectral resolution. Today’s highest fields comprise proton Larmor frequencies of 1.2 GHz and even larger field strengths are to be expected in the future. In protein triple resonance experiments, various carbon bandwidths need to be excited by selective pulses including the large aliphatic chemical shift range. When the spectrometer field strength is increased, the length of these pulses has to be decreased by the same factor, resulting in higher rf-amplitudes being necessary in order to cover the required frequency region. Currently available band-selective pulses like Q3/Q5 excite a narrow bandwidth compared to the necessary rf-amplitude. Because the maximum rf-power allowed in probeheads is limited, none of the selective universal rotation pulses reported so far is able to cover the full <span>(^{13})</span>C aliphatic region on 1.2 GHz spectrometers. In this work, we present band-selective 90° and 180° universal rotation pulses (SURBOP90 and SURBOP180) that have a higher ratio of selective bandwidth to maximum rf-amplitude than standard pulses. Simulations show that these pulses perform better than standard pulses, e. g. Q3/Q5, especially when rf-inhomogeneity is taken into account. The theoretical and experimental performance is demonstrated in offset profiles and by implementing the SURBOP pulses in an HNCACB experiment at 1.2 GHz.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00404-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4946477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pure shift amide detection in conventional and TROSY-type experiments of 13C,15N-labeled proteins","authors":"Jens D. Haller, Andrea Bodor, Burkhard Luy","doi":"10.1007/s10858-022-00406-z","DOIUrl":"10.1007/s10858-022-00406-z","url":null,"abstract":"<div><p>Large coupling networks in uniformly <sup>13</sup>C,<sup>15</sup>N-labeled biomolecules induce broad multiplets that even in flexible proteins are frequently not recognized as such. The reason is that given multiplets typically consist of a large number of individual resonances that result in a single broad line, in which individual components are no longer resolved. We here introduce a real-time pure shift acquisition scheme for the detection of amide protons which is based on <sup>13</sup>C-BIRD<sup>r,X</sup>. As a result the full homo- and heteronuclear coupling network can be suppressed at low power leading to real singlets at substantially improved resolution and uncompromised sensitivity. The method is tested on a small globular and an intrinsically disordered protein (IDP) where the average spectral resolution is increased by a factor of ~ 2 and higher. Equally important, the approach works without saturation of water magnetization for solvent suppression and exchanging amide protons are not affected by saturation transfer.\u0000</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00406-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4732483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicolas Bolik-Coulon, D. Flemming Hansen, Lewis E. Kay
{"title":"Optimizing frequency sampling in CEST experiments","authors":"Nicolas Bolik-Coulon, D. Flemming Hansen, Lewis E. Kay","doi":"10.1007/s10858-022-00403-2","DOIUrl":"10.1007/s10858-022-00403-2","url":null,"abstract":"<div><p>For the past decade chemical exchange saturation transfer (CEST) experiments have been successfully applied to study exchange processes in biomolecules involving sparsely populated, transiently formed conformers. Initial implementations focused on extensive sampling of the CEST frequency domain, requiring significant measurement times. Here we show that the lengthy sampling schemes often used are not optimal and that reduced frequency sampling schedules can be developed without a priori knowledge of the exchange parameters, that only depend on the chosen B<sub>1</sub> field, and, to a lesser extent, on the intrinsic transverse relaxation rates of ground state spins. The reduced sampling approach described here can be used synergistically with other methods for reducing measurement times such as those that excite multiple frequencies in the CEST dimension simultaneously, or make use of non-uniform sampling of indirectly detected time domains, to further decrease measurement times. The proposed approach is validated by analysis of simulated and experimental datasets.\u0000</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00403-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4186969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterization of conformational heterogeneity via higher-dimensionality, proton-detected solid-state NMR","authors":"Ekaterina Burakova, Suresh K. Vasa, Rasmus Linser","doi":"10.1007/s10858-022-00405-0","DOIUrl":"10.1007/s10858-022-00405-0","url":null,"abstract":"<div><p>Site-specific heterogeneity of solid protein samples can be exploited as valuable information to answer biological questions ranging from thermodynamic properties determining fibril formation to protein folding and conformational stability upon stress. In particular, for proteins of increasing molecular weight, however, site-resolved assessment without residue-specific labeling is challenging using established methodology, which tends to rely on carbon-detected 2D correlations. Here we develop purely chemical-shift-based approaches for assessment of relative conformational heterogeneity that allows identification of each residue via four chemical-shift dimensions. High dimensionality diminishes the probability of peak overlap in the presence of multiple, heterogeneously broadened resonances. Utilizing backbone dihedral-angle reconstruction from individual contributions to the peak shape either via suitably adapted prediction routines or direct association with a relational database, the methods may in future studies afford assessment of site-specific heterogeneity of proteins without site-specific labeling.</p></div>","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10858-022-00405-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4913103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to: Validation of protein backbone structures calculated from NMR angular restraints using Rosetta","authors":"Joel Lapin, Alexander A. Nevzorov","doi":"10.1007/s10858-022-00398-w","DOIUrl":"10.1007/s10858-022-00398-w","url":null,"abstract":"","PeriodicalId":613,"journal":{"name":"Journal of Biomolecular NMR","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2022-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5032333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}