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Cognate DNA Recognition by Engrailed Homeodomain Involves a Conformational Change Controlled via an Electrostatic-Spring-Loaded Latch. Int J Mol Sci 2022; 23:ijms23052412. [PMID: 35269555 PMCID: PMC8910618 DOI: 10.3390/ijms23052412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 02/01/2023] Open
Abstract
Transcription factors must scan genomic DNA, recognize the cognate sequence of their control element(s), and bind tightly to them. The DNA recognition process is primarily carried out by their DNA binding domains (DBD), which interact with the cognate site with high affinity and more weakly with any other DNA sequence. DBDs are generally thought to bind to their cognate DNA without changing conformation (lock-and-key). Here, we used nuclear magnetic resonance and circular dichroism to investigate the interplay between DNA recognition and DBD conformation in the engrailed homeodomain (enHD), as a model case for the homeodomain family of eukaryotic DBDs. We found that the conformational ensemble of enHD is rather flexible and becomes gradually more disordered as ionic strength decreases following a Debye–Hückel’s dependence. Our analysis indicates that enHD’s response to ionic strength is mediated by a built-in electrostatic spring-loaded latch that operates as a conformational transducer. We also found that, at moderate ionic strengths, enHD changes conformation upon binding to cognate DNA. This change is of larger amplitude and somewhat orthogonal to the response to ionic strength. As a consequence, very high ionic strengths (e.g., 700 mM) block the electrostatic-spring-loaded latch and binding to cognate DNA becomes lock-and-key. However, the interplay between enHD conformation and cognate DNA binding is robust across a range of ionic strengths (i.e., 45 to 300 mM) that covers the physiologically-relevant conditions. Therefore, our results demonstrate the presence of a mechanism for the conformational control of cognate DNA recognition on a eukaryotic DBD. This mechanism can function as a signal transducer that locks the DBD in place upon encountering the cognate site during active DNA scanning. The electrostatic-spring-loaded latch of enHD can also enable the fine control of DNA recognition in response to transient changes in local ionic strength induced by variate physiological processes.
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Bie LH, Fei JW, Gao J. Molecular mechanism of methyl-dependent and spatial-specific DNA recognition of c-Jun homodimer. J Mol Model 2021; 27:227. [PMID: 34264385 DOI: 10.1007/s00894-021-04840-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
DNA methylation is important in regulation of gene expression and normal development because it alters the interplay between protein and DNA. Experiments have shown that a single 5-methylcytosine at different CpG sites (mCpG) might have different effects on specific recognition, but the atomistic origin and dynamic details are largely unclear. In this work, we investigated the mechanism of monomethylation at different CpG sites in the cognate motif and the cooperativity of full methylation. By constructing four models of c-Jun/Jun protein binding to the 5[Formula: see text]-XGAGTCA-3[Formula: see text] (X represents C or methylated C) motif, we characterized the dynamics of the contact interface using the all-atom molecular dynamics method. Free energy analysis of MM/GBSA suggests that regardless of whether the C12pG13 site of the bottom strand is methylated, the effects from mC25 of the top strand are dominant and can moderately enhance the binding by [Formula: see text] 31 kcal/mol, whereas mC12 showed a relatively small contribution, in agreement with the experimental data. Remarkably, we found that this spatial-specific influence was induced by different regulatory rules. The influence of the mC25 site is mainly mediated by steric hindrance. The additional methyl group leads to the conformational changes in nearby residues and triggers an obvious structural bending in the protein, which results in the formation of a new T-Asn-C triad that enhances the specific recognition of TCA half-sites. The substitution of the methyl group at the mC12 site of the bottom strand breaks the original H-bonds directly. Such changes in electrostatic interactions also lead to the remote allosteric effects of protein by multifaceted interactions but have negligible contributions to binding. Although these two influence modes are different, they can both fine-tune the local environment, which might produce remote allosteric effects through protein-protein interactions. Further analysis reveals that the discrepancies in these two modes are primarily due to their location. Moreover, when both sites are methylated, the major determinant of binding specificity depends on the context and the location of the methylation site, which is the result of crosstalk and cooperativity.
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Affiliation(s)
- Li-Hua Bie
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jun-Wen Fei
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jun Gao
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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Kozak F, Kurzbach D. How to assess the structural dynamics of transcription factors by integrating sparse NMR and EPR constraints with molecular dynamics simulations. Comput Struct Biotechnol J 2021; 19:2097-2105. [PMID: 33995905 PMCID: PMC8085671 DOI: 10.1016/j.csbj.2021.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
We review recent advances in modeling structural ensembles of transcription factors from nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopic data, integrated with molecular dynamics (MD) simulations. We focus on approaches that confirm computed conformational ensembles by sparse constraints obtained from magnetic resonance. This combination enables the deduction of functional and structural protein models even if nuclear Overhauser effects (NOEs) are too scarce for conventional structure determination. We highlight recent insights into the folding-upon-DNA binding transitions of intrinsically disordered transcription factors that could be assessed using such integrative approaches.
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Affiliation(s)
- Fanny Kozak
- University Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Waehringer Str. 38, 1090 Vienna, Austria
| | - Dennis Kurzbach
- University Vienna, Faculty of Chemistry, Institute of Biological Chemistry, Waehringer Str. 38, 1090 Vienna, Austria
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Rabdano SO, Shannon MD, Izmailov SA, Gonzalez Salguero N, Zandian M, Purusottam RN, Poirier MG, Skrynnikov NR, Jaroniec CP. Histone H4 Tails in Nucleosomes: a Fuzzy Interaction with DNA. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sevastyan O. Rabdano
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
| | - Matthew D. Shannon
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | - Sergei A. Izmailov
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
| | | | - Mohamad Zandian
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | - Rudra N. Purusottam
- Department of Chemistry and Biochemistry The Ohio State University Columbus OH 43210 USA
| | | | - Nikolai R. Skrynnikov
- Laboratory of Biomolecular NMR St. Petersburg State University St. Petersburg 199034 Russian Federation
- Department of Chemistry Purdue University West Lafayette IN 47906 USA
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5
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Rabdano SO, Shannon MD, Izmailov SA, Gonzalez Salguero N, Zandian M, Purusottam RN, Poirier MG, Skrynnikov NR, Jaroniec CP. Histone H4 Tails in Nucleosomes: a Fuzzy Interaction with DNA. Angew Chem Int Ed Engl 2021; 60:6480-6487. [PMID: 33522067 DOI: 10.1002/anie.202012046] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/15/2020] [Indexed: 12/21/2022]
Abstract
The interaction of positively charged N-terminal histone tails with nucleosomal DNA plays an important role in chromatin assembly and regulation, modulating their susceptibility to post-translational modifications and recognition by chromatin-binding proteins. Here, we report residue-specific 15 N NMR relaxation rates for histone H4 tails in reconstituted nucleosomes. These data indicate that H4 tails are strongly dynamically disordered, albeit with reduced conformational flexibility compared to a free peptide with the same sequence. Remarkably, the NMR observables were successfully reproduced in a 2-μs MD trajectory of the nucleosome. This is an important step toward resolving an apparent inconsistency where prior simulations were generally at odds with experimental evidence on conformational dynamics of histone tails. Our findings indicate that histone H4 tails engage in a fuzzy interaction with nucleosomal DNA, underpinned by a variable pattern of short-lived salt bridges and hydrogen bonds, which persists at low ionic strength (0-100 mM NaCl).
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Affiliation(s)
- Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation
| | - Matthew D Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation
| | | | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Rudra N Purusottam
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Michael G Poirier
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russian Federation.,Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA
| | - Christopher P Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
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Lacabanne D, Boudet J, Malär AA, Wu P, Cadalbert R, Salmon L, Allain FHT, Meier BH, Wiegand T. Protein Side-Chain-DNA Contacts Probed by Fast Magic-Angle Spinning NMR. J Phys Chem B 2020; 124:11089-11097. [PMID: 33238710 PMCID: PMC7734624 DOI: 10.1021/acs.jpcb.0c08150] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
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Protein–nucleic
acid interactions are essential in a variety
of biological events ranging from the replication of genomic DNA to
the synthesis of proteins. Noncovalent interactions guide such molecular
recognition events, and protons are often at the center of them, particularly
due to their capability of forming hydrogen bonds to the nucleic acid
phosphate groups. Fast magic-angle spinning experiments (100 kHz)
reduce the proton NMR line width in solid-state NMR of fully protonated
protein–DNA complexes to such an extent that resolved proton
signals from side-chains coordinating the DNA can be detected. We
describe a set of NMR experiments focusing on the detection of protein
side-chains from lysine, arginine, and aromatic amino acids and discuss
the conclusions that can be obtained on their role in DNA coordination.
We studied the 39 kDa enzyme of the archaeal pRN1 primase complexed
with DNA and characterize protein–DNA contacts in the presence
and absence of bound ATP molecules.
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Affiliation(s)
| | - Julien Boudet
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Pengzhi Wu
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.,Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Loic Salmon
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.,Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Thomas Wiegand
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
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Abstract
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Molecular association of proteins with nucleic
acids is required
for many biological processes essential to life. Electrostatic interactions
via ion pairs (salt bridges) of nucleic acid phosphates and protein
side chains are crucial for proteins to bind to DNA or RNA. Counterions
around the macromolecules are also key constituents for the thermodynamics
of protein–nucleic acid association. Until recently, there
had been only a limited amount of experiment-based information about
how ions and ionic moieties behave in biological macromolecular processes.
In the past decade, there has been significant progress in quantitative
experimental research on ionic interactions with nucleic acids and
their complexes with proteins. The highly negatively charged surfaces
of DNA and RNA electrostatically attract and condense cations, creating
a zone called the ion atmosphere. Recent experimental studies were
able to examine and validate theoretical models on ions and their
mobility and interactions with macromolecules. The ionic interactions
are highly dynamic. The counterions rapidly diffuse within the ion
atmosphere. Some of the ions are released from the ion atmosphere
when proteins bind to nucleic acids, balancing the charge via intermolecular
ion pairs of positively charged side chains and negatively charged
backbone phosphates. Previously, the release of counterions had been
implicated indirectly by the salt-concentration dependence of the
association constant. Recently, direct detection of counterion
release by NMR spectroscopy
has become possible and enabled more accurate and quantitative analysis
of the counterion release and its entropic impact on the thermodynamics
of protein–nucleic acid association. Recent studies also revealed
the dynamic nature of ion pairs of protein side chains and nucleic
acid phosphates. These ion pairs undergo transitions between two major
states. In one of the major states, the cation and the anion are in
direct contact and form hydrogen bonds. In the other major state,
the cation and the anion are separated by water. Transitions between
these states rapidly occur on a picosecond to nanosecond time scale.
When proteins interact with nucleic acids, interfacial arginine (Arg)
and lysine (Lys) side chains exhibit considerably different behaviors.
Arg side chains show a higher propensity to form rigid contacts with
nucleotide bases, whereas Lys side chains tend to be more mobile at
the molecular interfaces. The dynamic ionic interactions may facilitate
adaptive molecular recognition and play both thermodynamic and kinetic
roles in protein–nucleic acid interactions.
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Affiliation(s)
- Binhan Yu
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
| | - B. Montgomery Pettitt
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
| | - Junji Iwahara
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-1068, United States
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Yoo J, Winogradoff D, Aksimentiev A. Molecular dynamics simulations of DNA-DNA and DNA-protein interactions. Curr Opin Struct Biol 2020; 64:88-96. [PMID: 32682257 DOI: 10.1016/j.sbi.2020.06.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022]
Abstract
The all-atom molecular dynamics method can characterize the molecular-level interactions in DNA and DNA-protein systems with unprecedented resolution. Recent advances in computational technologies have allowed the method to reveal the unbiased behavior of such systems at the microseconds time scale, whereas enhanced sampling approaches have matured enough to characterize the interaction free energy with quantitative precision. Here, we describe recent progress toward increasing the realism of such simulations by refining the accuracy of the molecular dynamics force field, and we highlight recent application of the method to systems of outstanding biological interest.
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Affiliation(s)
- Jejoong Yoo
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea; Center for Self-assembly and Complexity, Institute for Basic Science, Pohang 37673, Republic of Korea.
| | - David Winogradoff
- Department of Physics and the Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Aleksei Aksimentiev
- Department of Physics and the Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Kämpf K, Izmailov SA, Rabdano SO, Groves AT, Podkorytov IS, Skrynnikov NR. What Drives 15N Spin Relaxation in Disordered Proteins? Combined NMR/MD Study of the H4 Histone Tail. Biophys J 2018; 115:2348-2367. [PMID: 30527335 DOI: 10.1016/j.bpj.2018.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/07/2018] [Accepted: 11/12/2018] [Indexed: 12/26/2022] Open
Abstract
Backbone (15N) NMR relaxation is one of the main sources of information on dynamics of disordered proteins. Yet, we do not know very well what drives 15N relaxation in such systems, i.e., how different forms of motion contribute to the measurable relaxation rates. To address this problem, we have investigated, both experimentally and via molecular dynamics simulations, the dynamics of a 26-residue peptide imitating the N-terminal portion of the histone protein H4. One part of the peptide was found to be fully flexible, whereas the other part features some transient structure (a hairpin stabilized by hydrogen bonds). The following motional modes proved relevant for 15N relaxation. 1) Sub-picosecond librations attenuate relaxation rates according to S2 ∼0.85-0.90. 2) Axial peptide-plane fluctuations along a stretch of the peptide chain contribute to relaxation-active dynamics on a fast timescale (from tens to hundreds of picoseconds). 3) φ/ψ backbone jumps contribute to relaxation-active dynamics on both fast (from tens to hundreds of picoseconds) and slow (from hundreds of picoseconds to a nanosecond) timescales. The major contribution is from polyproline II (PPII) ↔ β transitions in the Ramachandran space; in the case of glycine residues, the major contribution is from PPII ↔ (β) ↔ rPPII transitions, in which rPPII is the mirror-image (right-handed) version of the PPII geometry, whereas β geometry plays the role of an intermediate state. 4) Reorientational motion of certain (sufficiently long-lived) elements of transient structure, i.e., rotational tumbling, contributes to slow relaxation-active dynamics on ∼1-ns timescale (however, it is difficult to isolate this contribution). In conclusion, recent advances in the area of force-field development have made it possible to obtain viable Molecular Dynamics models of protein disorder. After careful validation against the experimental relaxation data, these models can provide a valuable insight into mechanistic origins of spin relaxation in disordered peptides and proteins.
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Affiliation(s)
- Kerstin Kämpf
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Adam T Groves
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
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Pazos IM, Ma J, Mukherjee D, Gai F. Ultrafast Hydrogen-Bonding Dynamics in Amyloid Fibrils. J Phys Chem B 2018; 122:11023-11029. [PMID: 29883122 DOI: 10.1021/acs.jpcb.8b04642] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
While there are many studies on the subject of hydrogen-bonding dynamics in biological systems, few, if any, have investigated this fundamental process in amyloid fibrils. Herein, we seek to add insight into this topic by assessing the dynamics of a hydrogen bond buried in the dry interface of amyloid fibrils. To prepare a suitable model peptide system for this purpose, we introduce two mutations into the amyloid-forming Aβ16-22 peptide. The first one is a lysine analogue at position 19, which is used to help form structurally homogeneous fibrils, and the second one is an aspartic acid derivative (DM) at position 17, which is intended (1) to be used as a site-specific infrared probe and (2) to serve as a hydrogen-bond acceptor to lysine so that an inter-β-sheet hydrogen bond can be formed in the fibrils. Using both infrared spectroscopy and atomic force microscopy, we show that (1) this mutant peptide indeed forms well-defined fibrils, (2) when bulk solvent is removed, there is no detectable water present in the fibrils, (3) infrared results obtained with the DM probe are consistent with a protofibril structure that is composed of two antiparallel β-sheets stacked in a parallel fashion, leading to formation of the expected hydrogen bond. Using two-dimensional infrared spectroscopy, we further show that the dynamics of this hydrogen bond occur on a time scale of ∼2.3 ps, which is attributed to the rapid rotation of the -NH3+ group of lysine around its Cε-Nζ bond. Taken together, these results suggest that (1) DM is a useful infrared marker in facilitating structure determination of amyloid fibrils and (2) even in the tightly packed core of amyloid fibrils certain amino acid side chains can undergo ultrafast motions, hence contributing to the thermodynamic stability of the system.
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