1
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Andrews T, Seravallic J, Powers R. The reversible low-temperature instability of human DJ-1 oxidative states. Biopolymers 2024; 115:e23534. [PMID: 36972340 PMCID: PMC10948107 DOI: 10.1002/bip.23534] [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: 11/22/2022] [Revised: 02/21/2023] [Accepted: 03/07/2023] [Indexed: 03/29/2023]
Abstract
DJ-1 is a homodimeric protein that is centrally involved in various human diseases including Parkinson disease (PD). DJ-1 protects against oxidative damage and mitochondrial dysfunction through a homeostatic control of reactive oxygen species (ROS). DJ-1 pathology results from a loss of function, where ROS readily oxidizes a highly conserved and functionally essential cysteine (C106). The over-oxidation of DJ-1 C106 leads to a dynamically destabilized and biologically inactivated protein. An analysis of the structural stability of DJ-1 as a function of oxidative state and temperature may provide further insights into the role the protein plays in PD progression. NMR spectroscopy, circular dichroism, analytical ultracentrifugation sedimentation equilibrium, and molecular dynamics simulations were utilized to investigate the structure and dynamics of the reduced, oxidized (C106-SO2 - ), and over-oxidized (C106-SO3 - ) forms of DJ-1 for temperatures ranging from 5°C to 37°C. The three oxidative states of DJ-1 exhibited distinct temperature-dependent structural changes. A cold-induced aggregation occurred for the three DJ-1 oxidative states by 5°C, where the over-oxidized state aggregated at significantly higher temperatures than both the oxidized and reduced forms. Only the oxidized and over-oxidized forms of DJ-1 exhibited a mix state containing both folded and partially denatured protein that likely preserved secondary structure content. The relative amount of this denatured form of DJ-1 increased as the temperature was lowered, consistent with a cold-denaturation. Notably, the cold-induced aggregation and denaturation for the DJ-1 oxidative states were completely reversible. The dramatic changes in the structural stability of DJ-1 as a function of oxidative state and temperature are relevant to its role in PD and its functional response to oxidative stress.
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Affiliation(s)
- Tessa Andrews
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln NE 68588-0304, USA
| | - Javier Seravallic
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln NE 68588-0664, USA
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln NE 68588-0304, USA
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588-0664,USA
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln NE 68588-0304, USA
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2
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Abstract
Classical enzyme kinetic theories are summarized and linked with modern discoveries here. The sequential catalytic events along time axis by enzyme are analyzed at the molecular level, and by using master equations, this writing tries to connect the microscopic molecular behavior of enzyme to kinetic data (like velocity and catalytic coefficient k) obtained in experiment: 1/k = t equals to the sum of the times taken by the constituent individual steps. The relationships between catalytic coefficient k, catalytic rate or velocity, the amount of time taken by each step and physical or biochemical conditions of the system are discussed, and the perspective and hypothetic equations proposed here regarding diffusion, conformational change, chemical conversion, product release steps and the whole catalytic cycle provide an interpretation of previous experimental observations and can be testified by future experiments.
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3
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O'Brien ES, Fuglestad B, Lessen HJ, Stetz MA, Lin DW, Marques BS, Gupta K, Fleming KG, Wand AJ. Membrane Proteins Have Distinct Fast Internal Motion and Residual Conformational Entropy. Angew Chem Int Ed Engl 2020; 59:11108-11114. [PMID: 32277554 PMCID: PMC7318686 DOI: 10.1002/anie.202003527] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Indexed: 12/31/2022]
Abstract
The internal motions of integral membrane proteins have largely eluded comprehensive experimental characterization. Here the fast side-chain dynamics of the α-helical sensory rhodopsin II and the β-barrel outer membrane protein W have been investigated in lipid bilayers and detergent micelles by solution NMR relaxation techniques. Despite their differing topologies, both proteins have a similar distribution of methyl-bearing side-chain motion that is largely independent of membrane mimetic. The methyl-bearing side chains of both proteins are, on average, more dynamic in the ps-ns timescale than any soluble protein characterized to date. Accordingly, both proteins retain an extraordinary residual conformational entropy in the folded state, which provides a counterbalance to the absence of the hydrophobic effect. Furthermore, the high conformational entropy could greatly influence the thermodynamics underlying membrane-protein functions, including ligand binding, allostery, and signaling.
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Affiliation(s)
- Evan S. O'Brien
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
| | - Brian Fuglestad
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
- Present address: Department of ChemistryVirginia Commonwealth UniversityRichmondVA23284USA
| | - Henry J. Lessen
- Department of BiophysicsJohns Hopkins UniversityBaltimoreMD21218USA
| | - Matthew A. Stetz
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
| | - Danny W. Lin
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
| | - Bryan S. Marques
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
| | - Kushol Gupta
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
| | - Karen G. Fleming
- Department of BiophysicsJohns Hopkins UniversityBaltimoreMD21218USA
| | - A. Joshua Wand
- Department of Biochemistry & BiophysicsTexas A&M UniversityCollege StationTX77843USA
- Department of Biochemistry & BiophysicsUniversity of PennsylvaniaPerelman School of MedicinePhiladelphiaPA19104USA
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4
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Mendelman N, Meirovitch E. Conformational Entropy from Restricted Bond-Vector Motion in Proteins: The Symmetry of the Local Restrictions and Relation to NMR Relaxation. J Phys Chem B 2020; 124:4284-4292. [PMID: 32356984 PMCID: PMC7467720 DOI: 10.1021/acs.jpcb.0c02662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Locally mobile bond-vectors contribute to the conformational entropy of the protein, given by Sk ≡ S/k = -∫(Peq ln Peq)dΩ - ln∫dΩ. The quantity Peq = exp(-u)/Z is the orientational probability density, where Z is the partition function and u is the spatially restricting potential exerted by the immediate internal protein surroundings at the site of the motion of the bond-vector. It is appropriate to expand the potential, u, which restricts local rotational reorientation, in the basis set of the real combinations of the Wigner rotation matrix elements, D0KL. For small molecules dissolved in anisotropic media, one typically keeps the lowest even L, L = 2, nonpolar potential in axial or rhombic form. For bond-vectors anchored at the protein, the lowest odd L, L = 1, polar potential is to be used in axial or rhombic form. Here, we investigate the effect of the symmetry and polarity of these potentials on Sk. For L = 1 (L = 2), Sk is the same (differs) for parallel and perpendicular ordering. The plots of Sk as a function of the coefficients of the rhombic L = 1 (L = 2) potential exhibit high-symmetry (specific low-symmetry) patterns with parameter-range-dependent sensitivity. Similar statements apply to analogous plots of the potential minima. Sk is also examined as a function of the order parameters defined in terms of u. Graphs displaying these correlations, and applications illustrating their usage, are provided. The features delineated above are generally useful for devising orienting potentials that best suit given physical circumstances. They are particularly useful for bond-vectors acting as NMR relaxation probes in proteins, when their restricted local motion is analyzed with stochastic models featuring Wigner-function-made potentials. The relaxation probes could also be molecules adsorbed at surfaces, inserted into membranes, or interlocked within metal-organic frameworks.
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Affiliation(s)
- Netanel Mendelman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Eva Meirovitch
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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5
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O'Brien ES, Fuglestad B, Lessen HJ, Stetz MA, Lin DW, Marques BS, Gupta K, Fleming KG, Wand AJ. Membrane Proteins Have Distinct Fast Internal Motion and Residual Conformational Entropy. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Evan S. O'Brien
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
| | - Brian Fuglestad
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
- Present address: Department of Chemistry Virginia Commonwealth University Richmond VA 23284 USA
| | - Henry J. Lessen
- Department of Biophysics Johns Hopkins University Baltimore MD 21218 USA
| | - Matthew A. Stetz
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
| | - Danny W. Lin
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
| | - Bryan S. Marques
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
| | - Kushol Gupta
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
| | - Karen G. Fleming
- Department of Biophysics Johns Hopkins University Baltimore MD 21218 USA
| | - A. Joshua Wand
- Department of Biochemistry & Biophysics Texas A&M University College Station TX 77843 USA
- Department of Biochemistry & Biophysics University of Pennsylvania Perelman School of Medicine Philadelphia PA 19104 USA
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6
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Stetz MA, Caro JA, Kotaru S, Yao X, Marques BS, Valentine KG, Wand AJ. Characterization of Internal Protein Dynamics and Conformational Entropy by NMR Relaxation. Methods Enzymol 2018; 615:237-284. [PMID: 30638531 PMCID: PMC6364297 DOI: 10.1016/bs.mie.2018.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Recent studies suggest that the fast timescale motion of methyl-bearing side chains may play an important role in mediating protein activity. These motions have been shown to encapsulate the residual conformational entropy of the folded state that can potentially contribute to the energetics of protein function. Here, we provide an overview of how to characterize these motions using nuclear magnetic resonance (NMR) spin relaxation methods. The strengths and limitations of several techniques are highlighted in order to assist with experimental design. Particular emphasis is placed on the practical aspects of sample preparation, data collection, data fitting, and statistical analysis. Additionally, discussion of the recently refined "entropy meter" is presented and its use in converting NMR observables to conformational entropy is illustrated. Taken together, these methods should yield new insights into the complex interplay between structure and dynamics in protein function.
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Affiliation(s)
- Matthew A Stetz
- Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - José A Caro
- Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Sravya Kotaru
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Xuejun Yao
- Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Bryan S Marques
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Kathleen G Valentine
- Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - A Joshua Wand
- Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
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7
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Abstract
NMR-based studies of protein dynamics and molecular simulations have a synergistic relationship. Molecular simulations, in combination with interpretative theoretical models, leverage the dynamical information obtained from NMR. They provide the concrete physical schema underlying the quantities measured by NMR, and help extend the range of applications beyond the strictly dynamic properties. NMR data in turn provide concrete data to test and improve the potential functions used for simulation of dynamics of proteins. The concept of time correlation functions is central to the understanding of many dynamical processes. Their evaluation through atomistic simulations is discussed, with application to different dynamical quantities measured by NMR. While advances in computers have made such atomistic simulations almost routine, the companion use of simple interpretive models is stressed, to provide not just numbers but physical insight.
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Affiliation(s)
- Kim A Sharp
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States.
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8
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Capdevila DA, Edmonds KA, Campanello GC, Wu H, Gonzalez-Gutierrez G, Giedroc DP. Functional Role of Solvent Entropy and Conformational Entropy of Metal Binding in a Dynamically Driven Allosteric System. J Am Chem Soc 2018; 140:9108-9119. [PMID: 29953213 PMCID: PMC6425489 DOI: 10.1021/jacs.8b02129] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Allostery is a regulatory phenomenon whereby ligand binding to one site influences the binding of the same or a different ligand to another site on a macromolecule. The physical origins of allosteric regulation remain under intense investigation. In general terms, ligand-induced structural changes, perturbations of residue-specific dynamics, and surrounding solvent molecules all potentially contribute to the global energetics of allostery. While the role of solvent is generally well understood in regulatory events associated with major protein structural rearrangements, the degree to which protein dynamics impact solvent degrees of freedom is unclear, particularly in cases of dynamically driven allostery. With the aid of new crystal structures, extensive calorimetric and residue-specific dynamics studies over a range of time scales and temperatures, we dissect for the first time the relative degree to which changes in solvent entropy and residue-specific dynamics impact dynamically driven, allosteric inhibition of DNA binding by Zn in the zinc efflux repressor, CzrA (chromosomal zinc-regulated repressor). We show that non-native residue-specific dynamics in allosterically impaired CzrA mutants are accompanied by significant perturbations in solvent entropy that cannot be predicted from crystal structures. We conclude that functional dynamics are not necessarily restricted to protein residues but involve surface water molecules that may be responding to ligand (Zn)-mediated perturbations in protein internal motions that define the conformational ensemble, rather than major structural rearrangements.
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Affiliation(s)
- Daiana A. Capdevila
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102 United States
| | - Katherine A. Edmonds
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102 United States
| | - Gregory C. Campanello
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102 United States
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102 United States
| | - Giovanni Gonzalez-Gutierrez
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405 United States
| | - David P. Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102 United States
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405 United States
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9
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Noorani M, Azarpira N, Karimian K, Heli H. Erlotinib-loaded albumin nanoparticles: A novel injectable form of erlotinib and its in vivo efficacy against pancreatic adenocarcinoma ASPC-1 and PANC-1 cell lines. Int J Pharm 2017; 531:299-305. [DOI: 10.1016/j.ijpharm.2017.08.102] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/17/2017] [Accepted: 08/21/2017] [Indexed: 02/07/2023]
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10
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Abstract
Molecular recognition by proteins is fundamental to molecular biology. Dissection of the thermodynamic energy terms governing protein-ligand interactions has proven difficult, with determination of entropic contributions being particularly elusive. NMR relaxation measurements have suggested that changes in protein conformational entropy can be quantitatively obtained through a dynamical proxy, but the generality of this relationship has not been shown. Twenty-eight protein-ligand complexes are used to show a quantitative relationship between measures of fast side-chain motion and the underlying conformational entropy. We find that the contribution of conformational entropy can range from favorable to unfavorable, which demonstrates the potential of this thermodynamic variable to modulate protein-ligand interactions. For about one-quarter of these complexes, the absence of conformational entropy would render the resulting affinity biologically meaningless. The dynamical proxy for conformational entropy or "entropy meter" also allows for refinement of the contributions of solvent entropy and the loss in rotational-translational entropy accompanying formation of high-affinity complexes. Furthermore, structure-based application of the approach can also provide insight into long-lived specific water-protein interactions that escape the generic treatments of solvent entropy based simply on changes in accessible surface area. These results provide a comprehensive and unified view of the general role of entropy in high-affinity molecular recognition by proteins.
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11
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Entropy redistribution controls allostery in a metalloregulatory protein. Proc Natl Acad Sci U S A 2017; 114:4424-4429. [PMID: 28348247 DOI: 10.1073/pnas.1620665114] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Allosteric communication between two ligand-binding sites in a protein is a central aspect of biological regulation that remains mechanistically unclear. Here we show that perturbations in equilibrium picosecond-nanosecond motions impact zinc (Zn)-induced allosteric inhibition of DNA binding by the Zn efflux repressor CzrA (chromosomal zinc-regulated repressor). DNA binding leads to an unanticipated increase in methyl side-chain flexibility and thus stabilizes the complex entropically; Zn binding redistributes these motions, inhibiting formation of the DNA complex by restricting coupled fast motions and concerted slower motions. Allosterically impaired CzrA mutants are characterized by distinct nonnative fast internal dynamics "fingerprints" upon Zn binding, and DNA binding is weakly regulated. We demonstrate the predictive power of the wild-type dynamics fingerprint to identify key residues in dynamics-driven allostery. We propose that driving forces arising from dynamics can be harnessed by nature to evolve new allosteric ligand specificities in a compact molecular scaffold.
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12
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Schuetz AK, Kay LE. A Dynamic molecular basis for malfunction in disease mutants of p97/VCP. eLife 2016; 5. [PMID: 27828775 PMCID: PMC5102582 DOI: 10.7554/elife.20143] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 10/25/2016] [Indexed: 12/04/2022] Open
Abstract
p97/VCP is an essential, abundant AAA+ ATPase that is conserved throughout eukaryotes, with central functions in diverse processes ranging from protein degradation to DNA damage repair and membrane fusion. p97 has been implicated in the etiology of degenerative diseases and in cancer. Using Nuclear Magnetic Resonance spectroscopy we reveal how disease-causing mutations in p97 deregulate dynamics of the N-terminal domain that binds adaptor proteins involved in controlling p97 function. Our results provide a molecular basis for understanding how malfunction occurs whereby mutations shift the ADP-bound form of the enzyme towards an ATP-like state in a manner that correlates with disease severity. This deregulation interferes with the two-pronged binding of an adaptor that affects p97 function in lysosomal degradation of substrates. Subtle structural changes propagate from mutation sites to regions distal in space, defining allosteric networks that facilitate inter-domain communication, with potential implications for modulation of enzyme activity by drug molecules. DOI:http://dx.doi.org/10.7554/eLife.20143.001
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Affiliation(s)
- Anne K Schuetz
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Cananda.,Department of Chemistry, University of Toronto, Toronto, Canada
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Cananda.,Department of Chemistry, University of Toronto, Toronto, Canada.,Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, Canada
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13
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Vugmeyster L, Clark MA, Falconer IB, Ostrovsky D, Gantz D, Qiang W, Hoatson GL. Flexibility and Solvation of Amyloid-β Hydrophobic Core. J Biol Chem 2016; 291:18484-95. [PMID: 27402826 DOI: 10.1074/jbc.m116.740530] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Indexed: 11/06/2022] Open
Abstract
Amyloid fibril deposits found in Alzheimer disease patients are composed of amyloid-β (Aβ) protein forming a number of hydrophobic interfaces that are believed to be mostly rigid. We have investigated the μs-ms time-scale dynamics of the intra-strand hydrophobic core and interfaces of the fibrils composed of Aβ1-40 protein. Using solid-state (2)H NMR line shape experiments performed on selectively deuterated methyl groups, we probed the 3-fold symmetric and 2-fold symmetric polymorphs of native Aβ as well as the protofibrils of D23N Iowa mutant, associated with an early onset of Alzheimer disease. The dynamics of the hydrophobic regions probed at Leu-17, Leu-34, Val-36, and Met-35 side chains were found to be very pronounced at all sites and in all polymorphs of Aβ, with methyl axis motions persisting down to 230-200 K for most of the sites. The dominant mode of motions is the rotameric side chain jumps, with the Met-35 displaying the most complex multi-modal behavior. There are distinct differences in the dynamics among the three protein variants, with the Val-36 site displaying the most variability. Solvation of the fibrils does not affect methyl group motions within the hydrophobic core of individual cross-β subunits but has a clear effect on the motions at the hydrophobic interface between the cross-β subunits, which is defined by Met-35 contacts. In particular, hydration activates transitions between additional rotameric states that are not sampled in the dry protein. Thus, these results support the existence of water-accessible cavity recently predicted by molecular dynamics simulations and suggested by cryo-EM studies.
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Affiliation(s)
| | | | | | | | - Donald Gantz
- Boston University School of Medicine, Boston, Massachusetts 02118
| | - Wei Qiang
- Binghamton University, Binghamton, New York 13902, and
| | - Gina L Hoatson
- College of William and Mary, Williamsburg, Virginia 23187
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14
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Grimaldo M, Roosen-Runge F, Hennig M, Zanini F, Zhang F, Jalarvo N, Zamponi M, Schreiber F, Seydel T. Hierarchical molecular dynamics of bovine serum albumin in concentrated aqueous solution below and above thermal denaturation. Phys Chem Chem Phys 2016; 17:4645-55. [PMID: 25587698 DOI: 10.1039/c4cp04944f] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of proteins in solution is a complex and hierarchical process, affected by the aqueous environment as well as temperature. We present a comprehensive study on nanosecond time and nanometer length scales below, at, and above the denaturation temperature Td. Our experimental data evidence dynamical processes in protein solutions on three distinct time scales. We suggest a consistent physical picture of hierarchical protein dynamics: (i) self-diffusion of the entire protein molecule is confirmed to agree with colloid theory for all temperatures where the protein is in its native conformational state. At higher temperatures T > Td, the self-diffusion is strongly obstructed by cross-linking or entanglement. (ii) The amplitude of backbone fluctuations grows with increasing T, and a transition in its dynamics is observed above Td. (iii) The number of mobile side-chains increases sharply at Td while their average dynamics exhibits only little variations. The combination of quasi-elastic neutron scattering and the presented analytical framework provides a detailed microscopic picture of the protein molecular dynamics in solution, thereby reflecting the changes of macroscopic properties such as cluster formation and gelation.
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Affiliation(s)
- Marco Grimaldo
- Institut Max von Laue - Paul Langevin (ILL), CS 20156, F-38042 Grenoble, France.
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15
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Rosenzweig R, Farber P, Velyvis A, Rennella E, Latham MP, Kay LE. ClpB N-terminal domain plays a regulatory role in protein disaggregation. Proc Natl Acad Sci U S A 2015; 112:E6872-81. [PMID: 26621746 PMCID: PMC4687599 DOI: 10.1073/pnas.1512783112] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ClpB/Hsp100 is an ATP-dependent disaggregase that solubilizes and reactivates protein aggregates in cooperation with the DnaK/Hsp70 chaperone system. The ClpB-substrate interaction is mediated by conserved tyrosine residues located in flexible loops in nucleotide-binding domain-1 that extend into the ClpB central pore. In addition to the tyrosines, the ClpB N-terminal domain (NTD) was suggested to provide a second substrate-binding site; however, the manner in which the NTD recognizes and binds substrate proteins has remained elusive. Herein, we present an NMR spectroscopy study to structurally characterize the NTD-substrate interaction. We show that the NTD includes a substrate-binding groove that specifically recognizes exposed hydrophobic stretches in unfolded or aggregated client proteins. Using an optimized segmental labeling technique in combination with methyl-transverse relaxation optimized spectroscopy (TROSY) NMR, the interaction of client proteins with both the NTD and the pore-loop tyrosines in the 580-kDa ClpB hexamer has been characterized. Unlike contacts with the tyrosines, the NTD-substrate interaction is independent of the ClpB nucleotide state and protein conformational changes that result from ATP hydrolysis. The NTD interaction destabilizes client proteins, priming them for subsequent unfolding and translocation. Mutations in the NTD substrate-binding groove are shown to have a dramatic effect on protein translocation through the ClpB central pore, suggesting that, before their interaction with substrates, the NTDs block the translocation channel. Together, our findings provide both a detailed characterization of the NTD-substrate complex and insight into the functional regulatory role of the ClpB NTD in protein disaggregation.
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Affiliation(s)
- Rina Rosenzweig
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8;
| | - Patrick Farber
- Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
| | - Algirdas Velyvis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Enrico Rennella
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Michael P Latham
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
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16
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Harpole KW, O'Brien ES, Clark MA, McKnight CJ, Vugmeyster L, Wand AJ. The unusual internal motion of the villin headpiece subdomain. Protein Sci 2015; 25:423-32. [PMID: 26473993 DOI: 10.1002/pro.2831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 10/12/2015] [Indexed: 11/06/2022]
Abstract
The thermostable 36-residue subdomain of the villin headpiece (HP36) is the smallest known cooperatively folding protein. Although the folding and internal dynamics of HP36 and close variants have been extensively studied, there has not been a comprehensive investigation of side-chain motion in this protein. Here, the fast motion of methyl-bearing amino acid side chains is explored over a range of temperatures using site-resolved solution nuclear magnetic resonance deuterium relaxation. The squared generalized order parameters of methyl groups extensively spatially segregate according to motional classes. This has not been observed before in any protein studied using this methodology. The class segregation is preserved from 275 to 305 K. Motions detected in Helix 3 suggest a fast timescale of conformational heterogeneity that has not been previously observed but is consistent with a range of folding and dynamics studies. Finally, a comparison between the order parameters in solution with previous results based on solid-state nuclear magnetic resonance deuterium line shape analysis of HP36 in partially hydrated powders shows a clear disagreement for half of the sites. This result has significant implications for the interpretation of data derived from a variety of approaches that rely on partially hydrated protein samples.
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Affiliation(s)
- Kyle W Harpole
- Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, 19104-6059
| | - Evan S O'Brien
- Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, 19104-6059
| | - Matthew A Clark
- Department of Chemistry, University of Alaska Anchorage, Anchorage, Alaska, 99508
| | - C James McKnight
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, 02118
| | - Liliya Vugmeyster
- Department of Chemistry, University of Alaska Anchorage, Anchorage, Alaska, 99508.,Department of Chemistry, University of Colorado at Denver, Denver, Colorado, 80204
| | - A Joshua Wand
- Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, 19104-6059
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17
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DuBay KH, Bowman GR, Geissler PL. Fluctuations within folded proteins: implications for thermodynamic and allosteric regulation. Acc Chem Res 2015; 48:1098-105. [PMID: 25688669 DOI: 10.1021/ar500351b] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Folded protein structures are both stable and dynamic. Historically, our clearest window into these structures came from X-ray crystallography, which generally provided a static image of each protein's singular "folded state", highlighting its stability. Deviations away from that crystallographic structure were difficult to quantify, and as a result, their potential functional consequences were often neglected. However, several dynamical and statistical studies now highlight the structural variability that is present within the protein's folded state. Here we review mounting evidence of the importance of these structural rearrangements; both experiment and computation indicate that folded proteins undergo substantial fluctuations that can greatly influence their function. Crucially, recent studies have shown that structural elements of proteins, especially their side-chain degrees of freedom, fluctuate in ways that generate significant conformational heterogeneity. The entropy associated with these motions contributes to the folded structure's thermodynamic stability. In addition, since these fluctuations can shift in response to perturbations such as ligand binding, they may play an important role in the protein's capacity to respond to environmental cues. In one compelling example, the entropy associated with side-chain fluctuations contributes significantly to regulating the binding of calmodulin to a set of peptide ligands. The neglect of fluctuations within proteins' native states was often justified by the dense packing within folded proteins, which has inspired comparisons with crystalline solids. Many liquids, however, can achieve similarly dense packing yet fluidity is maintained through correlated molecular motions. Indeed, the studies we discuss favor comparison of folded proteins not with solids but instead with dense liquids, where the internal side chain fluidity is facilitated by collective motions that are correlated over long distances. These correlated rearrangements can enable allosteric communication between different parts of a protein, through subtle and varied channels. Such long-range correlations appear to be an innate feature of proteins in general, manifest even in molecules lacking known allosteric regulators and arising robustly from the physical nature of their internal environment. Given their ubiquity, it is only to be expected that, over time, nature has refined some subset of these correlated motions and put them to use. Native state fluctuations increasingly appear to be vital for proteins' natural functions. Understanding the diversity, origin, and range of these rearrangements may provide novel routes for rationally manipulating biomolecular activity.
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Affiliation(s)
- Kateri H. DuBay
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Gregory R. Bowman
- Department
of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Phillip L. Geissler
- Department
of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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18
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Sharp KA, O'Brien E, Kasinath V, Wand AJ. On the relationship between NMR-derived amide order parameters and protein backbone entropy changes. Proteins 2015; 83:922-30. [PMID: 25739366 DOI: 10.1002/prot.24789] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 01/29/2015] [Accepted: 02/17/2015] [Indexed: 12/23/2022]
Abstract
Molecular dynamics simulations are used to analyze the relationship between NMR-derived squared generalized order parameters of amide NH groups and backbone entropy. Amide order parameters (O(2) NH ) are largely determined by the secondary structure and average values appear unrelated to the overall flexibility of the protein. However, analysis of the more flexible subset (O(2) NH < 0.8) shows that these report both on the local flexibility of the protein and on a different component of the conformational entropy than that reported by the side chain methyl axis order parameters, O(2) axis . A calibration curve for backbone entropy vs. O(2) NH is developed, which accounts for both correlations between amide group motions of different residues, and correlations between backbone and side chain motions. This calibration curve can be used with experimental values of O(2) NH changes obtained by NMR relaxation measurements to extract backbone entropy changes, for example, upon ligand binding. In conjunction with our previous calibration for side chain entropy derived from measured O(2) axis values this provides a prescription for determination of the total protein conformational entropy changes from NMR relaxation measurements.
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Affiliation(s)
- Kim A Sharp
- Graduate Group in Biochemistry and Molecular Biophysics and the Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, 19104
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19
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Kasinath V, Fu Y, Sharp KA, Wand AJ. A Sharp Thermal Transition of Fast Aromatic‐Ring Dynamics in Ubiquitin. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201408220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Vignesh Kasinath
- Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104 (USA)
| | - Yinan Fu
- Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104 (USA)
| | - Kim A. Sharp
- Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104 (USA)
| | - A. Joshua Wand
- Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104 (USA)
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20
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Kasinath V, Fu Y, Sharp KA, Wand AJ. A sharp thermal transition of fast aromatic-ring dynamics in ubiquitin. Angew Chem Int Ed Engl 2014; 54:102-7. [PMID: 25476230 DOI: 10.1002/anie.201408220] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Indexed: 11/06/2022]
Abstract
Aromatic amino acid side chains have a rich role within proteins and are often central to their structure and function. Suitable isotopic-labelling strategies enable studies of sub-nanosecond aromatic-ring dynamics using solution NMR relaxation methods. Surprisingly, it was found that the three aromatic side chains in human ubiquitin show a sharp thermal dynamical transition at approximately 312 K. Hydrostatic pressure has little effect on the low-temperature behavior, but somewhat decreases the amplitude of motion in the high-temperature regime. Therefore, below the transition temperature, ring motion is largely librational. Above this temperature, a complete ring-rotation process that is fully consistent with a continuous diffusion not requiring the transient creation of a large activated free volume occurs. Molecular dynamics simulations qualitatively corroborate this view and reinforce the notion that the dynamical character of the protein interior has much more liquid-alkane-like properties than previously appreciated.
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Affiliation(s)
- Vignesh Kasinath
- Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104 (USA)
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21
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Reverse micelles as a tool for probing solvent modulation of protein dynamics: Reverse micelle encapsulated hemoglobin. Chem Phys 2013; 430:88-97. [PMID: 24039330 DOI: 10.1016/j.chemphys.2013.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Hydration waters impact protein dynamics. Dissecting the interplay between hydration waters and dynamics requires a protein that manifests a broad range of dynamics. Proteins in reverse micelles (RMs) have promise as tools to achieve this objective because the water content can be manipulated. Hemoglobin is an appropriate tool with which to probe hydration effects. We describe both a protocol for hemoglobin encapsulation in reverse micelles and a facile method using PEG and cosolvents to manipulate water content. Hydration properties are probed using the water-sensitive fluorescence from Hb bound pyranine and covalently attached Badan. Protein dynamics are probed through ligand recombination traces derived from photodissociated carbonmonoxy hemoglobin on a log scale that exposes the potential role of both α and β solvent fluctuations in modulating protein dynamics. The results open the possibility of probing hydration level phenomena in this system using a combination of NMR and optical probes.
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22
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Wand AJ. The dark energy of proteins comes to light: conformational entropy and its role in protein function revealed by NMR relaxation. Curr Opin Struct Biol 2012; 23:75-81. [PMID: 23246280 DOI: 10.1016/j.sbi.2012.11.005] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/19/2012] [Indexed: 11/12/2022]
Abstract
Historically it has been virtually impossible to experimentally determine the contribution of residual protein entropy to fundamental protein activities such as the binding of ligands. Recent progress has illuminated the possibility of employing NMR relaxation methods to quantitatively determine the role of changes in conformational entropy in molecular recognition by proteins. The method rests on using fast internal protein dynamics as a proxy. Initial results reveal a large and variable role for conformational entropy in the binding of ligands by proteins. Such a role for conformational entropy in molecular recognition has significant implications for enzymology, signal transduction, allosteric regulation and the development of protein-directed pharmaceuticals.
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Affiliation(s)
- A Joshua Wand
- The Johnson Research Foundation and Department of Biochemistry & Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-6059, USA.
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23
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Johnson E. Separability between overall and internal motion: a protein folding problem. Proteins 2012; 80:2645-51. [PMID: 22945391 DOI: 10.1002/prot.24175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/23/2012] [Accepted: 08/26/2012] [Indexed: 12/29/2022]
Abstract
The separability between overall and internal motions is evaluated over multiple folding trajectories of the villin headpiece subdomain. The analysis, which relies on the Prompers-Brüschweiler separability index, offers a potentially useful perspective on protein folding. The protein is considered folded in this study, not when it reaches some static target, but rather when it tumbles as a dynamically constrained object. The analysis also demonstrates how the separability index, when applied to protein folding simulations, can facilitate the analysis of NMR relaxation data.
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Affiliation(s)
- Eric Johnson
- Department of Chemistry and Physical Sciences, College of Mount St. Joseph, Cincinnati, OH 45233, USA.
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24
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Fu Y, Kasinath V, Moorman VR, Nucci NV, Hilser VJ, Wand AJ. Coupled motion in proteins revealed by pressure perturbation. J Am Chem Soc 2012; 134:8543-50. [PMID: 22452540 PMCID: PMC3415598 DOI: 10.1021/ja3004655] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cooperative nature of protein substructure and internal motion is a critical aspect of their functional competence about which little is known experimentally. NMR relaxation is used here to monitor the effects of high pressure on fast internal motion in the protein ubiquitin. In contrast to the main chain, the motions of the methyl-bearing side chains have a large and variable pressure dependence. Within the core, this pressure sensitivity correlates with the magnitude of motion at ambient pressure. Spatial clustering of the dynamic response to applied hydrostatic pressure is also seen, indicating localized cooperativity of motion on the sub-nanosecond time scale and suggesting regions of variable compressibility. These and other features indicate that the native ensemble contains a significant fraction of members with characteristics ascribed to the recently postulated "dry molten globule". The accompanying variable side-chain conformational entropy helps complete our view of the thermodynamic architecture underlying protein stability, folding, and function.
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Affiliation(s)
- Yinan Fu
- Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Vignesh Kasinath
- Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Veronica R. Moorman
- Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Nathaniel V. Nucci
- Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Vincent J. Hilser
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218 USA
| | - A. Joshua Wand
- Graduate Group in Biochemistry and Molecular Biophysics and Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
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25
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Sabo TM, Bakhtiari D, Walter KFA, McFeeters RL, Giller K, Becker S, Griesinger C, Lee D. Thermal coefficients of the methyl groups within ubiquitin. Protein Sci 2012; 21:562-70. [PMID: 22334336 PMCID: PMC3375756 DOI: 10.1002/pro.2045] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 11/11/2022]
Abstract
Physiological processes such as protein folding and molecular recognition are intricately linked to their dynamic signature, which is reflected in their thermal coefficient. In addition, the local conformational entropy is directly related to the degrees of freedom, which each residue possesses within its conformational space. Therefore, the temperature dependence of the local conformational entropy may provide insight into understanding how local dynamics may affect the stability of proteins. Here, we analyze the temperature dependence of internal methyl group dynamics derived from the cross-correlated relaxation between dipolar couplings of two CH bonds within ubiquitin. Spanning a temperature range from 275 to 308 K, internal methyl group dynamics tend to increase with increasing temperature, which translates to a general increase in local conformational entropy. With this data measured over multiple temperatures, the thermal coefficient of the methyl group order parameter, the characteristic thermal coefficient, and the local heat capacity were obtained. By analyzing the distribution of methyl group thermal coefficients within ubiquitin, we found that the N-terminal region has relatively high thermostability. These results indicate that methyl groups contribute quite appreciably to the total heat capacity of ubiquitin through the regulation of local conformational entropy.
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Affiliation(s)
- T Michael Sabo
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Davood Bakhtiari
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Korvin F A Walter
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Robert L McFeeters
- Department of Chemistry, University of Alabama in HuntsvilleHuntsville, Alabama 35899
| | - Karin Giller
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Stefan Becker
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Christian Griesinger
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
| | - Donghan Lee
- Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical ChemistryGöttingen 37077, Germany
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26
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Pistolesi S, Tjandra N. Temperature dependence of molecular interactions involved in defining stability of glutamine binding protein and its complex with L-glutamine. Biochemistry 2012; 51:643-52. [PMID: 22206385 PMCID: PMC3513781 DOI: 10.1021/bi201494h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The temperature dependence of dynamic parameters derived from nuclear magnetic resonance (NMR) relaxation data is related to conformational entropy of the system under study. This provides information such as macromolecules stability and thermodynamics of ligand binding. We studied the temperature dependence of NMR order parameter of glutamine binding protein (GlnBP), a periplasmic binding protein (PBP) highly specific to L-glutamine associated with its ABC transporter, with the goal of elucidating the dynamical differences between the respective ligand bound and free forms. We found that the protein-ligand interaction, which is stabilized at higher temperature, has a striking effect on the stability of the hydrophobic core of the large domain of GlnBP. Moreover, in contrast to what was found for less specific PBPs, the decreasing backbone motion of the hinge region at increasing temperature supports the idea that the likelihood that GlnBP can adopt a ligand free closed conformation in solution diminishes at higher temperatures. Our results support the induced-fit model as mode of action for GlnBP. In addition, we found that the backbones of residues involved in a salt bridge do not necessarily become more rigid as the temperature rises as it was previously suggested [Vinther, J. M., et al. (2011) J. Am. Chem. Soc., 133, 271-278]. Our results show that for this to happen these residues have to also directly interact with a region of the protein that is becoming more rigid as the temperature increases.
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Affiliation(s)
- Sara Pistolesi
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Bethesda, MD 20892
| | - Nico Tjandra
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Bethesda, MD 20892
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27
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Liao X, Long D, Li DW, Brüschweiler R, Tugarinov V. Probing side-chain dynamics in proteins by the measurement of nine deuterium relaxation rates per methyl group. J Phys Chem B 2011; 116:606-20. [PMID: 22098066 DOI: 10.1021/jp209304c] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We demonstrate the feasibility of the measurement of up to nine deuterium spin relaxation rates in 13CHD2 and 13CH2D methyl isotopomers of small proteins. In addition to five measurable 2H relaxation rates in a 13CH2D methyl group (Millet, O.; Muhandiram, D. R.; Skrynnikov, N. R.; Kay, L. E. J. Am. Chem. Soc. 2002, 124, 6439-48), the measurement of additional four rates of (nearly) single-exponentially decaying magnetization terms in methyl groups of the 13CHD2 variety is reported. Consistency relationships between 2H spin relaxation rates measured in the two different types of methyl groups are derived and verified experimentally for a subset of methyl-containing side chains in the protein ubiquitin. A detailed comparison of methyl-bearing side-chain dynamics parameters obtained from relaxation measurements in 13CH2D and 13CHD2 methyls of ubiquitin at 10, 27, and 40 °C reveals that transverse 2H relaxation rates in 13CHD2 groups are reliable and accurate reporters of the amplitudes of methyl 3-fold axis motions (S(axis)2) for protein molecules with global molecular tumbling times τ(C) >~9 ns. For smaller molecules, simple correction of transverse 2H relaxation rates in 13CHD2 groups is sufficient for the derivation of robust measures of order. Residue-specific distributions of S(axis)2 are consistent with atomic-detail molecular dynamics (MD) results. Both 13CHD2- and 13CH2D-derived S(axis)2 values are in good overall agreement with those obtained from 1 μs MD simulations at all the three temperatures, although some differences in the site-specific temperature dependence between MD- and 2H-relaxation-derived S(axis)2 values are observed.
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Affiliation(s)
- Xinli Liao
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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28
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Sidhu A, Surolia A, Robertson AD, Sundd M. A hydrogen bond regulates slow motions in ubiquitin by modulating a β-turn flip. J Mol Biol 2011; 411:1037-48. [PMID: 21741979 DOI: 10.1016/j.jmb.2011.06.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 06/16/2011] [Accepted: 06/27/2011] [Indexed: 10/18/2022]
Abstract
Proteins exist as conformational ensembles composed of multiple interchanging substates separated by kinetic barriers. Interconverting conformations are often difficult to probe, owing to their sparse population and transient nature. Here, we report the identification and characterization of a subset of conformations in ubiquitin that participate in microsecond-to-millisecond motions in the amides of Ile23, Asn25, and Thr55. A novel side chain to the backbone hydrogen bond that regulates these motions has also been identified. Combining our NMR studies with the available X-ray data, we have unearthed the physical process underlying slow motions-the interconversion of a type I into a type II β-turn flip at residues Glu51 through Arg54. Interestingly, the dominant conformer of wild-type ubiquitin observed in solution near neutral pH is only represented by about 22% of the crystal structures. The conformers generated as a result of the dynamics of the hydrogen bond appear to be correlated to ligand recognition by ubiquitin.
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Affiliation(s)
- Arshdeep Sidhu
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
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29
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Liu J, Yin DC, Guo YZ, Wang XK, Xie SX, Lu QQ, Liu YM. Selecting temperature for protein crystallization screens using the temperature dependence of the second virial coefficient. PLoS One 2011; 6:e17950. [PMID: 21479212 PMCID: PMC3068142 DOI: 10.1371/journal.pone.0017950] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 02/16/2011] [Indexed: 11/19/2022] Open
Abstract
Protein crystals usually grow at a preferable temperature which is however not known for a new protein. This paper reports a new approach for determination of favorable crystallization temperature, which can be adopted to facilitate the crystallization screening process. By taking advantage of the correlation between the temperature dependence of the second virial coefficient (B(22)) and the solubility of protein, we measured the temperature dependence of B(22) to predict the temperature dependence of the solubility. Using information about solubility versus temperature, a preferred crystallization temperature can be proposed. If B(22) is a positive function of the temperature, a lower crystallization temperature is recommended; if B(22) shows opposite behavior with respect to the temperature, a higher crystallization temperature is preferred. Otherwise, any temperature in the tested range can be used.
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Affiliation(s)
- Jun Liu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
| | - Da-Chuan Yin
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
- * E-mail:
| | - Yun-Zhu Guo
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
| | - Xi-Kai Wang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
| | - Si-Xiao Xie
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
| | - Qin-Qin Lu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
| | - Yong-Ming Liu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
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30
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Reddy T, Rainey JK. Interpretation of biomolecular NMR spin relaxation parameters. Biochem Cell Biol 2010; 88:131-42. [PMID: 20453916 DOI: 10.1139/o09-152] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Biomolecular nuclear magnetic resonance (NMR) spin relaxation experiments provide exquisite information on the picosecond to nanosecond timescale motions of bond vectors. Spin-lattice (T1) and spin-spin (T2) relaxation times and the steady-state nuclear Overhauser effect (NOE) are the first set of parameters extracted from typical 15N or 13C NMR relaxation experiments. Therefore, verifying that T1, T2, and NOE are consistent with theoretical predictions is an important step before carrying out the more detailed model-free and reduced spectral density mapping analyses commonly employed. In this mini-review, we discuss the essential motional parameters used to describe biomolecular dynamics in the context of a variety of examples of folded and intrinsically disordered proteins and peptides in aqueous and membrane mimetic environments. Estimates of these parameters can be used as input for an online interface, introduced herein, allowing plotting of trends of T1, T2, and NOE with magnetic field strength. The plots may serve as a first-check to the spectroscopist preparing to embark on a detailed NMR relaxation analysis.
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Affiliation(s)
- Tyler Reddy
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 1X5 Canada
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31
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Frederick KK, Sharp KA, Warischalk N, Wand AJ. Re-evaluation of the model-free analysis of fast internal motion in proteins using NMR relaxation. J Phys Chem B 2008; 112:12095-103. [PMID: 18759409 DOI: 10.1021/jp8038576] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NMR spin relaxation retains a central role in the characterization of the fast internal motion of proteins and their complexes. Knowledge of the distribution and amplitude of the motion of amino acid side chains is critical for the interpretation of the dynamical proxy for the residual conformational entropy of proteins, which can potentially significantly contribute to the entropy of protein function. A popular treatment of NMR relaxation phenomena in macromolecules dissolved in liquids is the so-called model-free approach of Lipari and Szabo. The robustness of the mode-free approach has recently been strongly criticized and the remarkable range and structural context of the internal motion of proteins, characterized by such NMR relaxation techniques, attributed to artifacts arising from the model-free treatment, particularly with respect to the symmetry of the underlying motion. We develop an objective quantification of both spatial and temporal asymmetry of motion and re-examine the foundation of the model-free treatment. Concerns regarding the robustness of the model-free approach to asymmetric motion appear to be generally unwarranted. The generalized order parameter is robustly recovered. The sensitivity of the model-free treatment to asymmetric motion is restricted to the effective correlation time, which is by definition a normalized quantity and not a true time constant and therefore of much less interest in this context. With renewed confidence in the model-free approach, we then examine the microscopic distribution of side chain motion in the complex between calcium-saturated calmodulin and the calmodulin-binding domain of the endothelial nitric oxide synthase. Deuterium relaxation is used to characterize the motion of methyl groups in the complex. A remarkable range of Lipari-Szabo model-free generalized order parameters are seen with little correlation with basic structural parameters such as the depth of burial. These results are contrasted with the homologous complex with the neuronal nitric oxide synthase calmodulin-binding domain, which has distinctly different thermodynamic origins for high affinity binding.
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Affiliation(s)
- Kendra King Frederick
- Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, USA
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32
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Song XJ, Simplaceanu V, Ho NT, Ho C. Effector-induced structural fluctuation regulates the ligand affinity of an allosteric protein: binding of inositol hexaphosphate has distinct dynamic consequences for the T and R states of hemoglobin. Biochemistry 2008; 47:4907-15. [PMID: 18376851 PMCID: PMC2493540 DOI: 10.1021/bi7023699] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study reports distinct dynamic consequences for the T- and R-states of human normal adult hemoglobin (Hb A) due to the binding of a heterotropic allosteric effector, inositol hexaphosphate (IHP). A nuclear magnetic resonance (NMR) technique based on modified transverse relaxation optimized spectroscopy (TROSY) has been used to investigate the effect of conformational exchange of Hb A in both deoxy and CO forms, in the absence and presence of IHP, at 14.1 and 21.1 T, and at 37 degrees C. Our results show that the majority of the polypeptide backbone amino acid residues of deoxy- and carbonmonoxy-forms of Hb A in the absence of IHP is not mobile on the micros-ms time scale, with the exception of several amino acid residues, that is, beta109Val and beta132Lys in deoxy-Hb A, and alpha40Lys in HbCO A. The mobility of alpha40Lys in HbCO A can be explained by the crystallographic data showing that the H-bond between alpha40Lys and beta146His in deoxy-Hb A is absent in HbCO A. However, the conformational exchange of beta109Val, which is located in the intradimer (alpha 1beta 1 or alpha 2beta 2) interface, is not consistent with the crystallographic observations that show rigid packing at this site. IHP binding appears to rigidify alpha40Lys in HbCO A, but does not significantly affect the flexibility of beta109Val in deoxy-Hb A. In the presence of IHP, several amino acid residues, especially those at the interdimer (alpha 1beta 2 or alpha 2beta 1) interface of HbCO A, exhibit significant conformational exchange. The affected residues include the proximal beta92His in the beta-heme pocket, as well as some other residues located in the flexible joint (betaC helix-alphaFG corner) and switch (alphaC helix-betaFG corner) regions that play an important role in the dimer-dimer rotation of Hb during the oxygenation process. These findings suggest that, upon IHP binding, HbCO A undergoes a conformational fluctuation near the R-state but biased toward the T-state, apparently along the trajectory of its allosteric transition, accompanied by structural fluctuations in the heme pocket of the beta-chain. In contrast, no significant perturbation of the dynamic features on the ms-micros time scale has been observed upon IHP binding to deoxy-Hb A. We propose that the allosteric effector-induced quaternary structural fluctuation may contribute to the reduced ligand affinity of ligated hemoglobin. Conformational exchange mapping of the beta-chain of HbCO A observed at 21.1 T shows significantly increased scatter in the chemical exchange contribution to the transverse relaxation rate ( R ex) values, relative to those at lower fields, due to the enhanced effect of the local chemical shift anisotropy (CSA) fluctuation. A spring-on-scissors model is proposed to interpret the dynamic phenomena induced by the heterotropic effector, IHP.
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Affiliation(s)
- Xiang-jin Song
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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33
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Biophysical study of thermal denaturation of apo-calmodulin: dynamics of native and unfolded states. Biophys J 2008; 95:5247-56. [PMID: 18223007 DOI: 10.1529/biophysj.107.120147] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Apo-calmodulin, a small, mainly alpha, soluble protein is a calcium-dependent protein activator. This article presents a study of internal dynamics of native and thermal unfolded apo-calmodulin, using quasi-elastic neutron scattering. This technique can probe protein internal dynamics in the picosecond timescale and in the nanometer length-scale. It appears that a dynamical transition is associated with thermal denaturation of apo-calmodulin. This dynamical transition goes together with a decrease of the confinement of hydrogen atoms, a decrease of immobile protons proportion and an increase of dynamical heterogeneity. The comparison of native and unfolded states dynamics suggests that the dynamics of protein atoms is more influenced by their distance to the backbone than by their solvent exposure.
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Song XJ, Yuan Y, Simplaceanu V, Sahu SC, Ho NT, Ho C. A comparative NMR study of the polypeptide backbone dynamics of hemoglobin in the deoxy and carbonmonoxy forms. Biochemistry 2007; 46:6795-803. [PMID: 17497935 PMCID: PMC2533159 DOI: 10.1021/bi602654u] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Model-free-based NMR dynamics studies have been undertaken for polypeptide backbone amide N-H bond vectors for both the deoxy and carbonmonoxy forms of chain-specific, isotopically (15N and 2H) labeled tetrameric hemoglobin (Hb) using 15N-relaxation parameters [longitudinal relaxation rate (R1), transverse relaxation rate (R2), and heteronuclear nuclear Overhauser effect (NOE)] measured at two temperatures (29 and 34 degrees C) and two magnetic field strengths (11.7 and 14.1 T). In both deoxy and carbonmonoxy forms of human normal adult hemoglobin (Hb A), the amide N-H bonds of most amino acid residues are rigid on the fast time scale (nanosecond to picosecond), except for the loop regions and certain helix-helix connections. Although rigid in deoxy-Hb A, beta146His has been found to be free from restriction of its backbone motions in the CO form, presumably due to the rupture of its hydrogen bond/salt bridge network. We now have direct dynamics evidence for this structural transition of Hb in solution. While remarkably flexible in the deoxy state, alpha31Arg and beta123Thr, neighbors in the intradimer (alpha1beta1) interface, exhibit stiffening upon CO binding. These findings imply a role for alpha31Arg and beta123Thr in the intradimer communication but contradict the results from X-ray crystallography. We have also found that there is considerable flexibility in the intradimer (alpha1beta1) interface (i.e., B, G, and H helices and the GH corner) and possible involvement of several amino acid residues (e.g., alpha31Arg, beta3Leu, beta41Phe, beta123Thr, and beta146His) in the allosteric pathway. Several amino acid residues at the intradimer interfaces, such as beta109Val, appear to be involved in possible conformational exchange processes. The dynamic picture derived from the present study provides new insights into the traditional description of the stereochemical mechanism for the cooperative oxygenation of Hb A based on X-ray crystallographic results.
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Affiliation(s)
| | | | | | | | | | - Chien Ho
- *Address all Correspondence to: Dr. Chien Ho, Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, Phone 412-268-3395; fax, 412-268-7083; Email,
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