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Ganguly HK, Ludwig BA, Tressler CM, Bhatt MR, Pandey AK, Quinn CM, Bai S, Yap GPA, Zondlo NJ. 4,4-Difluoroproline as a Unique 19F NMR Probe of Proline Conformation. Biochemistry 2024; 63:1131-1146. [PMID: 38598681 DOI: 10.1021/acs.biochem.3c00697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Despite the importance of proline conformational equilibria (trans versus cis amide and exo versus endo ring pucker) on protein structure and function, there is a lack of convenient ways to probe proline conformation. 4,4-Difluoroproline (Dfp) was identified to be a sensitive 19F NMR-based probe of proline conformational biases and cis-trans isomerism. Within model compounds and disordered peptides, the diastereotopic fluorines of Dfp exhibit similar chemical shifts (ΔδFF = 0-3 ppm) when a trans X-Dfp amide bond is present. In contrast, the diastereotopic fluorines exhibit a large (ΔδFF = 5-12 ppm) difference in chemical shift in a cis X-Dfp prolyl amide bond. DFT calculations, X-ray crystallography, and solid-state NMR spectroscopy indicated that ΔδFF directly reports on the relative preference of one proline ring pucker over the other: a fluorine which is pseudo-axial (i.e., the pro-4R-F in an exo ring pucker, or the pro-4S-F in an endo ring pucker) is downfield, while a fluorine which is pseudo-equatorial (i.e., pro-4S-F when exo, or pro-4R-F when endo) is upfield. Thus, when a proline is disordered (a mixture of exo and endo ring puckers, as at trans-Pro in peptides in water), it exhibits a small Δδ. In contrast, when the Pro is ordered (i.e., when one ring pucker is strongly preferred, as in cis-Pro amide bonds, where the endo ring pucker is strongly favored), a large Δδ is observed. Dfp can be used to identify inherent induced order in peptides and to quantify proline cis-trans isomerism. Using Dfp, we discovered that the stable polyproline II helix (PPII) formed in the denatured state (8 M urea) exhibits essentially equal populations of the exo and endo proline ring puckers. In addition, the data with Dfp suggested the specific stabilization of PPII by water over other polar solvents. These data strongly support the importance of carbonyl solvation and n → π* interactions for the stabilization of PPII. Dfp was also employed to quantify proline cis-trans isomerism as a function of phosphorylation and the R406W mutation in peptides derived from the intrinsically disordered protein tau. Dfp is minimally sterically disruptive and can be incorporated in expressed proteins, suggesting its broad application in understanding proline cis-trans isomerization, protein folding, and local order in intrinsically disordered proteins.
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Affiliation(s)
- Himal K Ganguly
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Brice A Ludwig
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Caitlin M Tressler
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Megh R Bhatt
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Anil K Pandey
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Caitlin M Quinn
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Shi Bai
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Glenn P A Yap
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Neal J Zondlo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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2
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Sebák F, Ecsédi P, Nyitray L, Bodor A. Assignment of the disordered, proline-rich N-terminal domain of the tumour suppressor p53 protein using 1H N and 1H α-detected NMR measurements. BIOMOLECULAR NMR ASSIGNMENTS 2023; 17:309-314. [PMID: 37861971 PMCID: PMC10630184 DOI: 10.1007/s12104-023-10160-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/07/2023] [Indexed: 10/21/2023]
Abstract
Protein p53 is mostly known for playing a key role in tumour suppression, and mutations in the p53 gene are amongst the most frequent genomic events accompanying oncogenic transformation. Continuous research is conducted to target disordered proteins/protein regions for cancer therapy, for which atomic level information is also necessary. The disordered N-terminal part of p53 contains the transactivation and the proline-rich domains-which besides being abundant in proline residues-contains repetitive Pro-Ala motifs. NMR assignment of such repetitive, proline-rich regions is challenging due to the lack of amide protons in the 1HN-detected approaches, as well as due to the small chemical shift dispersion. In the present study we perform the full assignment of the p531-100 region by applying a combination of 1HN- and 1Hα-detected NMR experiments. We also show the increased information content when using real-time homo- and heteronuclear decoupled acquisition schemes. On the other hand, we highlight the presence of minor proline species, and using Pro-selective experiments we determine the corresponding cis or trans conformation. Secondary chemical shifts for (Cα-Cβ) atoms indicate the disordered nature of this region, with expected helical tendency for the TAD1 region. As the role of the proline-rich domain is yet not well understood our results can contribute to further successful investigations.
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Affiliation(s)
- Fanni Sebák
- Analytical and BioNMR Laboratory, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest, 1117, Hungary
| | - Péter Ecsédi
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary
| | - László Nyitray
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary
| | - Andrea Bodor
- Analytical and BioNMR Laboratory, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest, 1117, Hungary.
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3
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Kuncewicz K, Bojko M, Battin C, Karczyńska A, Sieradzan A, Sikorska E, Węgrzyn K, Wojciechowicz K, Wardowska A, Steinberger P, Rodziewicz-Motowidło S, Spodzieja M. BTLA-derived peptides as inhibitors of BTLA/HVEM complex formation - design, synthesis and biological evaluation. Biomed Pharmacother 2023; 165:115161. [PMID: 37473684 DOI: 10.1016/j.biopha.2023.115161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023] Open
Abstract
Immune checkpoints can be divided into co-stimulatory and co-inhibitory molecules that regulate the activation and effector functions of T cells. The co-inhibitory pathways mediated by ICPs are used by cancer cells to escape from immune surveillance, and therefore the blockade of these receptor/ligand interactions is one of the strategies used in the treatment of cancer. The two main pathways currently under investigation are CTLA-4/CD80/CD86 and PD-1/PD-L1, and the monoclonal Abs targeting them have shown potent immunomodulatory effects and activity in clinical environments. Another interesting target in cancer treatment is the BTLA/HVEM complex. Binding of BTLA protein on T cells to HVEM on cancer cells leads to inhibition of T cell proliferation and cytokine production. In the presented work, we focused on blocking the HVEM protein using BTLA-derived peptides. Based on the crystal structure of the BTLA/HVEM complex and MM/GBSA analysis performed here, we designed and synthesized peptides, specifically fragments of BTLA protein. We subsequently checked the inhibitory capacities of these compounds using ELISA and a cellular reporter platform. Two of these peptides, namely BTLA(35-43) and BTLA(33-64)C58Abu displayed the most promising properties, and we therefore performed further studies to evaluate their affinity to HVEM protein, their stability in plasma and their effect on viability of human PBMCs. In addition, the 3D structure for the peptide BTLA(33-64)C58Abu was determined using NMR. Obtained data confirmed that the BTLA-derived peptides could be the basis for future drugs and their immunomodulatory potential merits further examination.
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Affiliation(s)
- Katarzyna Kuncewicz
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Magdalena Bojko
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Claire Battin
- Medical University of Vienna, Institute of Immunology, Division of Immune Receptors and T cell Activation, Lazarettgasse 19, 1090 Vienna, Austria
| | - Agnieszka Karczyńska
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Adam Sieradzan
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Emilia Sikorska
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Katarzyna Węgrzyn
- University of Gdańsk, Intercollegiate Faculty of Biotechnology of the University of Gdańsk and the Medical University of Gdańsk, Abrahama 58, 80-307 Gdańsk, Poland
| | - Karolina Wojciechowicz
- Medical University of Gdańsk, Department of Physiopathology, Dębinki 7, 80-210 Gdańsk, Poland
| | - Anna Wardowska
- Medical University of Gdańsk, Department of Physiopathology, Dębinki 7, 80-210 Gdańsk, Poland
| | - Peter Steinberger
- Medical University of Vienna, Institute of Immunology, Division of Immune Receptors and T cell Activation, Lazarettgasse 19, 1090 Vienna, Austria
| | | | - Marta Spodzieja
- University of Gdańsk, Faculty of Chemistry, Wita Stwosza 63, 80-308 Gdańsk, Poland.
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4
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Gurung D, Danielson JA, Tasnim A, Zhang JT, Zou Y, Liu JY. Proline Isomerization: From the Chemistry and Biology to Therapeutic Opportunities. BIOLOGY 2023; 12:1008. [PMID: 37508437 PMCID: PMC10376262 DOI: 10.3390/biology12071008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/27/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
Proline isomerization, the process of interconversion between the cis- and trans-forms of proline, is an important and unique post-translational modification that can affect protein folding and conformations, and ultimately regulate protein functions and biological pathways. Although impactful, the importance and prevalence of proline isomerization as a regulation mechanism in biological systems have not been fully understood or recognized. Aiming to fill gaps and bring new awareness, we attempt to provide a wholistic review on proline isomerization that firstly covers what proline isomerization is and the basic chemistry behind it. In this section, we vividly show that the cause of the unique ability of proline to adopt both cis- and trans-conformations in significant abundance is rooted from the steric hindrance of these two forms being similar, which is different from that in linear residues. We then discuss how proline isomerization was discovered historically followed by an introduction to all three types of proline isomerases and how proline isomerization plays a role in various cellular responses, such as cell cycle regulation, DNA damage repair, T-cell activation, and ion channel gating. We then explore various human diseases that have been linked to the dysregulation of proline isomerization. Finally, we wrap up with the current stage of various inhibitors developed to target proline isomerases as a strategy for therapeutic development.
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Affiliation(s)
- Deepti Gurung
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Jacob A Danielson
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Afsara Tasnim
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH 43606, USA
| | - Jian-Ting Zhang
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Yue Zou
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Jing-Yuan Liu
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Cell and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH 43606, USA
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5
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Kovács D, Bodor A. The influence of random-coil chemical shifts on the assessment of structural propensities in folded proteins and IDPs. RSC Adv 2023; 13:10182-10203. [PMID: 37006359 PMCID: PMC10065145 DOI: 10.1039/d3ra00977g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/15/2023] [Indexed: 04/03/2023] Open
Abstract
In studying secondary structural propensities of proteins by nuclear magnetic resonance (NMR) spectroscopy, secondary chemical shifts (SCSs) serve as the primary atomic scale observables. For SCS calculation, the selection of an appropriate random coil chemical shift (RCCS) dataset is a crucial step, especially when investigating intrinsically disordered proteins (IDPs). The scientific literature is abundant in such datasets, however, the effect of choosing one over all the others in a concrete application has not yet been studied thoroughly and systematically. Hereby, we review the available RCCS prediction methods and to compare them, we conduct statistical inference by means of the nonparametric sum of ranking differences and comparison of ranks to random numbers (SRD-CRRN) method. We try to find the RCCS predictors best representing the general consensus regarding secondary structural propensities. The existence and the magnitude of resulting differences on secondary structure determination under varying sample conditions (temperature, pH) are demonstrated and discussed for globular proteins and especially IDPs.
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Affiliation(s)
- Dániel Kovács
- ELTE, Eötvös Loránd University, Institute of Chemistry, Analytical and BioNMR Laboratory Pázmány Péter sétány 1/A Budapest 1117 Hungary
- Eötvös Loránd University, Hevesy György PhD School of Chemistry Pázmány Péter sétány 1/A Budapest 1117 Hungary
| | - Andrea Bodor
- ELTE, Eötvös Loránd University, Institute of Chemistry, Analytical and BioNMR Laboratory Pázmány Péter sétány 1/A Budapest 1117 Hungary
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6
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Killoran PM, Hanson GSM, Verhoork SJM, Smith M, Del Gobbo D, Lian L, Coxon CR. Probing Peptidylprolyl Bond cis/trans Status Using Distal 19 F NMR Reporters. Chemistry 2023; 29:e202203017. [PMID: 36550088 PMCID: PMC10946801 DOI: 10.1002/chem.202203017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
A method for measuring peptidylprolyl bond cis-trans conformational status in peptide models is described, using 4-fluorophenylalanine (4FPhe) as a distal reporter for 19 F NMR. The %cis-Pro population was measured for peptides of the general structure Ac-X-Pro-Z-Ala-Ala-4FPhe (X and Z are proteinogenic amino acids) at pH 7.4, and provided conformational populations consistent with literature values obtained by more complex methods. This approach was applied to probe the prolyl bond status in pentapeptide models of the intrinsically disordered C-terminal region of α-synuclein, which mirrored the preferences in the Ac-X-Pro-Z-Ala-4FPhe models. Advantageously, the 19 F reporter group does not need to be adjacent to or attached to proline to provide quantifiable signals and distal 4-fluorophenylalanines can be placed so as not to influence prolyl bond conformation. Finally, we demonstrated that the prolyl bond status is not significantly affected by pH when there are ionisable amino acid residues at the carboxyl side of proline, which makes 19 F NMR an invaluable tool with which to study proline isomerism at a range of pHs and in different solvents and buffers.
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Affiliation(s)
- Patrick M. Killoran
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityLiverpoolMerseysideL3 3AFUK
| | - George S. M. Hanson
- EaStChem School of ChemistryThe University of Edinburgh Joseph Black BuildingDavid Brewster RoadEdinburghEH14 4ASUK
| | - Sanne J. M. Verhoork
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityLiverpoolMerseysideL3 3AFUK
| | - Madeleine Smith
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityLiverpoolMerseysideL3 3AFUK
| | - Davide Del Gobbo
- School of Pharmacy and Biomolecular SciencesLiverpool John Moores UniversityLiverpoolMerseysideL3 3AFUK
| | - Lu‐Yun Lian
- Institute of SystemsMolecular and Integrative BiologyThe University of LiverpoolCrown StreetLiverpoolL69 7ZBUK
| | - Christopher R. Coxon
- EaStChem School of ChemistryThe University of Edinburgh Joseph Black BuildingDavid Brewster RoadEdinburghEH14 4ASUK
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7
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Tomiyama R, So M, Yamaguchi K, Miyanoiri Y, Sakurai K. The residual structure of acid-denatured β 2 -microglobulin is relevant to an ordered fibril morphology. Protein Sci 2023; 32:e4487. [PMID: 36321362 PMCID: PMC9793977 DOI: 10.1002/pro.4487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/15/2022] [Accepted: 10/29/2022] [Indexed: 11/09/2022]
Abstract
β2 -Microglobulin (β2m) forms amyloid fibrils in vitro under acidic conditions. Under these conditions, the residual structure of acid-denatured β2m is relevant to seeding and fibril extension processes. Disulfide (SS) bond-oxidized β2m has been shown to form rigid, ordered fibrils, whereas SS bond-reduced β2m forms curvy, less-ordered fibrils. These findings suggest that the presence of an SS bond affects the residual structure of the monomer, which subsequently influences the fibril morphology. To clarify this process, we herein performed NMR experiments. The results obtained revealed that oxidized β2m contained a residual structure throughout the molecule, including the N- and C-termini, whereas the residual structure of the reduced form was localized and other regions had a random coil structure. The range of the residual structure in the oxidized form was wider than that of the fibril core. These results indicate that acid-denatured β2m has variable conformations. Most conformations in the ensemble cannot participate in fibril formation because their core residues are hidden by residual structures. However, when hydrophobic residues are exposed, polypeptides competently form an ordered fibril. This conformational selection phase may be needed for the ordered assembly of amyloid fibrils.
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Affiliation(s)
- Ryosuke Tomiyama
- Graduate School of Biology‐oriented Science and TechnologyKindai UniversityWakayamaJapan
| | - Masatomo So
- Institute for Protein ResearchOsaka UniversityOsakaJapan,Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
| | - Keiichi Yamaguchi
- Global Center for Medical Engineering and InformaticsOsaka UniversitySuitaJapan
| | | | - Kazumasa Sakurai
- Graduate School of Biology‐oriented Science and TechnologyKindai UniversityWakayamaJapan,High Pressure Protein Research Center, Institute of Advanced TechnologyKindai UniversityWakayamaJapan
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8
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Newcombe EA, Delaforge E, Hartmann-Petersen R, Skriver K, Kragelund BB. How phosphorylation impacts intrinsically disordered proteins and their function. Essays Biochem 2022; 66:901-913. [PMID: 36350035 PMCID: PMC9760426 DOI: 10.1042/ebc20220060] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022]
Abstract
Phosphorylation is the most common post-translational modification (PTM) in eukaryotes, occurring particularly frequently in intrinsically disordered proteins (IDPs). These proteins are highly flexible and dynamic by nature. Thus, it is intriguing that the addition of a single phosphoryl group to a disordered chain can impact its function so dramatically. Furthermore, as many IDPs carry multiple phosphorylation sites, the number of possible states increases, enabling larger complexities and novel mechanisms. Although a chemically simple and well-understood process, the impact of phosphorylation on the conformational ensemble and molecular function of IDPs, not to mention biological output, is highly complex and diverse. Since the discovery of the first phosphorylation site in proteins 75 years ago, we have come to a much better understanding of how this PTM works, but with the diversity of IDPs and their capacity for carrying multiple phosphoryl groups, the complexity grows. In this Essay, we highlight some of the basic effects of IDP phosphorylation, allowing it to serve as starting point when embarking on studies into this topic. We further describe how recent complex cases of multisite phosphorylation of IDPs have been instrumental in widening our view on the effect of protein phosphorylation. Finally, we put forward perspectives on the phosphorylation of IDPs, both in relation to disease and in context of other PTMs; areas where deep insight remains to be uncovered.
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Affiliation(s)
- Estella A Newcombe
- REPIN, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- The Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
| | - Elise Delaforge
- REPIN, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- The Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
| | - Rasmus Hartmann-Petersen
- REPIN, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
| | - Karen Skriver
- REPIN, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
| | - Birthe B Kragelund
- REPIN, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
- The Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, DK-2200 Copenhagen N, Denmark
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The Disordered EZH2 Loop: Atomic Level Characterization by 1H N- and 1H α-Detected NMR Approaches, Interaction with the Long Noncoding HOTAIR RNA. Int J Mol Sci 2022; 23:ijms23116150. [PMID: 35682829 PMCID: PMC9181245 DOI: 10.3390/ijms23116150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 02/06/2023] Open
Abstract
The 96-residue-long loop of EZH2 is proposed to play a role in the interaction with long non-coding RNAs (lncRNAs) and to contribute to EZH2 recruitment to the chromatin. However, molecular details of RNA recognition have not been described so far. Cellular studies have suggested that phosphorylation of the Thr345 residue localized in this loop influences RNA binding; however, no mechanistic explanation has been offered. To address these issues, a systematic NMR study was performed. As the 1HN-detected NMR approach presents many challenges under physiological conditions, our earlier developed, as well as improved, 1Hα-detected experiments were used. As a result of the successful resonance assignment, the obtained chemical shift values indicate the highly disordered nature of the EZH2 loop, with some nascent helical tendency in the Ser407–Ser412 region. Further investigations conducted on the phosphomimetic mutant EZH2T345D showed that the mutation has only a local effect, and that the loop remains disordered. On the other hand, the mutation influences the cis/trans Pro346 equilibrium. Interactions of both the wild-type and the phosphomimetic mutant with the lncRNA HOTAIR140 (1–140 nt) highlight that the Thr367–Ser375 region is affected. This segment does not resemble any of the previously reported RNA-binding motifs, therefore the identified binding region is unique. As no structural changes occur in the EZH2 loop upon RNA binding, we can consider the protein–RNA interaction as a “fuzzy” complex.
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Szabó CL, Sebák F, Bodor A. Monitoring Protein Global and Local Parameters in Unfolding and Binding Studies: The Extended Applicability of the Diffusion Coefficient─Molecular Size Empirical Relations. Anal Chem 2022; 94:7885-7891. [PMID: 35617314 DOI: 10.1021/acs.analchem.2c00481] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Protein unfolding and denaturation are main issues in biochemical and pharmaceutical research. Using a global parameter, the translational diffusion coefficient D, folded, unfolded, and intrinsically disordered proteins of a given molar mass M can be distinguished based on their distinct hydrodynamic properties. For broader applications, we provide generalized, PFG-NMR-based empirical D-M relations validated at different temperatures and ready to use with the corresponding corrections in different media. We demonstrate that these relations enable a more accurate molecular mass determination and show fewer potential errors than those of the common methods based on small-molecular diffusion standards. We monitor unfolding of three model proteins using 8 M urea and dimethyl sulfoxide (DMSO)-water mixtures as denaturing agents, highlighting the effect of disulfide bonds. Denaturation in 8 M urea is pH-dependent; in addition, for proteins with highly stable disulfide bonds, a reducing agent (TCEP) is required to achieve complete unfolding. Regarding the effect of local parameters, we show that at low DMSO concentrations─common conditions in pharmaceutical binding studies─the PFG-NMR-derived global parameters are not significantly affected. Still, the atomic environments can change, and the bound solvent molecule can inhibit the binding of a partner molecule. Using proteins with natural isotopic abundance, this effect can be proven by fast 1H-15N 2D correlation spectra. Our results enable fast and easy estimation of protein molecular mass and the degree of folding in various media; moreover, the effect of the cosolvent on the atomic-level structure can be traced without the need of isotope labeling.
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Affiliation(s)
- Csenge Lilla Szabó
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary.,Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Fanni Sebák
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Andrea Bodor
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
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11
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Sebák F, Horváth LB, Kovács D, Szolomájer J, Tóth GK, Babiczky Á, Bősze S, Bodor A. Novel Lysine-Rich Delivery Peptides of Plant Origin ERD and Human S100: The Effect of Carboxyfluorescein Conjugation, Influence of Aromatic and Proline Residues, Cellular Internalization, and Penetration Ability. ACS OMEGA 2021; 6:34470-34484. [PMID: 34963932 PMCID: PMC8697381 DOI: 10.1021/acsomega.1c04637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/25/2021] [Indexed: 06/14/2023]
Abstract
The need for novel drug delivery peptides is an important issue of the modern pharmaceutical research. Here, we test K-rich peptides from plant dehydrin ERD14 (ERD-A, ERD-B, and ERD-C) and the C-terminal CPP-resembling region of S100A4 (S100) using the 5(6)-carboxyfluorescein (Cf) tag at the N-terminus. Via a combined pH-dependent NMR and fluorescence study, we analyze the effect of the Cf conjugation/modification on the structural behavior, separately investigating the (5)-Cf and (6)-Cf forms. Flow cytometry results show that all peptides internalize; however, there is a slight difference between the cellular internalization of (5)- and (6)-Cf-peptides. We indicate the possible importance of residues with an aromatic sidechain and proline. We prove that ERD-A localizes mostly in the cytosol, ERD-B and S100 have partial colocalization with lysosomal staining, and ERD-C mainly localizes within vesicle-like compartments, while the uptake mechanism mainly occurs through energy-dependent paths.
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Affiliation(s)
- Fanni Sebák
- Institute
of Chemistry, ELTE−Eötvös
Loránd University, Pázmány Péter sétány 1/a, H-1117 Budapest, Hungary
- Doctoral
School of Pharmaceutical Sciences, Semmelweis
University, Üllői
út 26, H-1085 Budapest, Hungary
| | - Lilla Borbála Horváth
- ELKH-ELTE
Research Group of Peptide Chemistry, Eötvös Loránd
Research Network, Eötvös Loránd
University, Pázmány Péter sétány 1/a, H-1117 Budapest, Hungary
- National
Public Health Center, Albert Flórián út 2-6, Budapest H-1097, Hungary
- Hevesy
György PhD School of Chemistry, ELTE
Eötvös Loránd University, Pázmány Péter sétány
1/a, H-1117 Budapest, Hungary
| | - Dániel Kovács
- Institute
of Chemistry, ELTE−Eötvös
Loránd University, Pázmány Péter sétány 1/a, H-1117 Budapest, Hungary
- Hevesy
György PhD School of Chemistry, ELTE
Eötvös Loránd University, Pázmány Péter sétány
1/a, H-1117 Budapest, Hungary
| | - János Szolomájer
- Department
of Medical Chemistry, University of Szeged, Dóm tér 8, H-6720 Szeged, Hungary
| | - Gábor K. Tóth
- Department
of Medical Chemistry, University of Szeged, Dóm tér 8, H-6720 Szeged, Hungary
| | - Ákos Babiczky
- Institute
of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
- Doctoral
School of Psychology/Cognitive Science, Budapest University of Technology and Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary
| | - Szilvia Bősze
- ELKH-ELTE
Research Group of Peptide Chemistry, Eötvös Loránd
Research Network, Eötvös Loránd
University, Pázmány Péter sétány 1/a, H-1117 Budapest, Hungary
- National
Public Health Center, Albert Flórián út 2-6, Budapest H-1097, Hungary
| | - Andrea Bodor
- Institute
of Chemistry, ELTE−Eötvös
Loránd University, Pázmány Péter sétány 1/a, H-1117 Budapest, Hungary
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