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Pastore A, Temussi P. When "IUPs" were "BAPs": How to study the nonconformation of intrinsically unfolded polyaminoacid chains. Biopolymers 2016; 100:592-600. [PMID: 23896858 DOI: 10.1002/bip.22363] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/12/2013] [Indexed: 01/21/2023]
Abstract
Ideas often recur. It has been pointed out recently that proteins are not always the well-structured entities we have become accustomed to from crystallographic studies, but may be intrinsically unstructured or contain unstructured regions. This feature, far from making these proteins less interesting, is an essential requirement for their function. Fascinating though it may be, the concept of so-called intrinsically unfolded (or unordered) proteins (IUPs), also often referred to as intrinsically disordered proteins (IDPs), is not new: it directly links back to the 1970s when the attention of many structural biologists was focused on biologically active peptides, which like IUPs lack a specific defined conformation. The recurrent nature of this concept may now be of topical interest since it suggests the transfer, upon suitable adaptation, of old tools to develop new ideas. Here, we review some of the approaches that were developed for the study of peptides and discuss how they could inspire powerful new methodologies for the study of IUPs.
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Affiliation(s)
- Annalisa Pastore
- National Institute for Medical Research, The Ridgeway, London, NW7 1AA, United Kingdom
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2
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Dama M, Berger S. Ionic liquid crystals as alignment medium to measure residual dipolar couplings for carbohydrates. Carbohydr Res 2013; 377:44-7. [PMID: 23806381 DOI: 10.1016/j.carres.2013.05.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 05/23/2013] [Accepted: 05/30/2013] [Indexed: 11/19/2022]
Abstract
Ionic liquids consisting of N-dodecyl-N-methyl pyrrolidinium bromide [C12MPB] in a mixture with D2O, decanol, and DMSO were for the first time found to give anisotropic molecular alignment in magnetic fields and are useful to measure residual dipolar couplings (RDCs) from polar analytes, for example, glucose. The system shows less quadrupolar splitting of the deuterated solvent signal compared with other liquid crystal systems and hence less undesired line broadening.
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Affiliation(s)
- Murali Dama
- Institute of Analytical Chemistry, University Leipzig, Leipzig, Germany
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3
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Dürr UN, Gildenberg M, Ramamoorthy A. The magic of bicelles lights up membrane protein structure. Chem Rev 2012; 112:6054-74. [PMID: 22920148 PMCID: PMC3497859 DOI: 10.1021/cr300061w] [Citation(s) in RCA: 266] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Indexed: 12/12/2022]
Affiliation(s)
| | - Melissa Gildenberg
- Biophysics
and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055,
United States
| | - Ayyalusamy Ramamoorthy
- Biophysics
and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055,
United States
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4
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Dama M, Berger S. Polyacetylenes as a new alignment medium to measure residual dipolar couplings for chiral organic molecules. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.09.060] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Dama M, Berger S. Polyisocyanides As a New Alignment Medium To Measure Residual Dipolar Couplings for Small Organic Molecules. Org Lett 2011; 14:241-3. [DOI: 10.1021/ol202547y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Murali Dama
- Institute for Analytical Chemistry, University of Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
| | - Stefan Berger
- Institute for Analytical Chemistry, University of Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
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6
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Residual Dipolar Couplings Report on the Active Conformation of Rhodopsin-Bound Protein Fragments. Top Curr Chem (Cham) 2006. [DOI: 10.1007/128_2006_088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Yan J, Zartler ER. Application of residual dipolar couplings in organic compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43:53-64. [PMID: 15578593 DOI: 10.1002/mrc.1505] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Residual dipolar couplings (RDCs) induced by anisotropic media are a powerful tool for the structure determination of biomolecules through NMR spectroscopy. Recent advances have proven it to be a valuable tool for determination of the stereochemistry of organic molecules. By simple inspection or order matrix calculations, RDCs provide unambiguous information about the relative configurations or complete stereochemistry of organic compounds.
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Affiliation(s)
- Jiangli Yan
- Triad Therapeutics, Inc., San Diego, CA 92121, USA.
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8
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Zandomeneghi G, Meier BH. Adiabatic-passage cross polarization in N-15 NMR spectroscopy of peptides weakly associated to phospholipids: determination of large RDC. JOURNAL OF BIOMOLECULAR NMR 2004; 30:303-309. [PMID: 15754056 DOI: 10.1007/s10858-004-3097-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Accepted: 08/03/2004] [Indexed: 05/24/2023]
Abstract
Structural information can be extracted from one-bond residual dipolar couplings (RDC) measured in NMR spectra of systems in field-ordered media. RDC can be on the order of J-couplings if the anisotropy of alignment is approximately 10(-2), 10-fold stronger than that typically used for structural studies of water-soluble proteins. In such systems the performance of (1)H--> (15)N polarization transfer methods of the INEPT type is not satisfactory. In this study we show the effectiveness of adiabatic-passage cross-polarization (APCP) in transferring the (1)H--> (15)N polarization in the bicelle-associated peptide Leucine Enkephalin (Lenk). APCP is efficient both in static samples and in samples spun at the magic angle (MAS) or any other angle of the spinning axis to the magnetic field (variable-angle spinning, VAS). The anisotropic spectrum of an aligned static sample and the isotropic spectrum of the sample under MAS provide a set of possible values for the (1)H-(15)N RDC of phospholipid-associated Lenk. The unambiguous determination of the (1)H-(15)N RDC was accomplished by means of VAS experiments.
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Marcotte I, Separovic F, Auger M, Gagné SM. A multidimensional 1H NMR investigation of the conformation of methionine-enkephalin in fast-tumbling bicelles. Biophys J 2004; 86:1587-600. [PMID: 14990485 PMCID: PMC1303993 DOI: 10.1016/s0006-3495(04)74226-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2003] [Accepted: 11/07/2003] [Indexed: 11/22/2022] Open
Abstract
Enkephalins are pentapeptides found in the central nervous system. It is believed that these neuropeptides interact with the nerve cell membrane to adopt a conformation suitable for their binding to an opiate receptor. In this work, we have determined the three-dimensional structure of methionine-enkephalin (Menk) in fast-tumbling bicelles using multidimensional (1)H NMR. Bicelles were selected as model membranes because both their bilayer organization and composition resemble those of natural biomembranes. The effect of the membrane composition on the peptide conformation was explored using both zwitterionic (PC bicelles) and negatively charged bicelles (Bic/PG). Pulsed field gradient experiments allowed the determination of the proportion of Menk bound to the model membranes. Approximately 60% of the water-soluble enkephalin was found to associate to the bicellar systems. Structure calculations from torsion angle and NOE-based distance constraints suggest the presence of both micro - and delta-selective conformers of Menk in each system and slightly different conformers in PC bicelles and Bic/PG. As opposed to previous studies of enkephalins in membrane mimetic systems, our results show that these opiate peptides could adopt several conformations in a membrane environment, which is consistent with the flexibility and poor selectivity of enkephalins.
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Affiliation(s)
- Isabelle Marcotte
- Département de Chimie, Centre de Recherche en Sciences et Ingénierie des Macromolécules, Université Laval, Québec, Québec, Canada, G1K 7P4
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10
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Marcotte I, Dufourc EJ, Ouellet M, Auger M. Interaction of the neuropeptide met-enkephalin with zwitterionic and negatively charged bicelles as viewed by 31P and 2H solid-state NMR. Biophys J 2003; 85:328-39. [PMID: 12829487 PMCID: PMC1303088 DOI: 10.1016/s0006-3495(03)74477-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The interaction of the neuropeptide methionine-enkephalin (Menk) with bicelles was investigated by solid-state NMR. Bicelles composed of dimyristoylphosphatidylcholine (DMPC) and dicaproylphosphatidylcholine (DCPC) were modified to investigate the effect of the lipid headgroup and electrostatic charges on the association with Menk. A total of 10 mol % of DMPC was replaced by zwitterionic phosphatidylethanolamine (DMPE), anionic phosphatidylglycerol (DMPG), or phosphatidylserine (DMPS). The preparation of DMPE-doped bicelles (Bic/PE) is reported for the first time. The (31)P and (2)H NMR results revealed changes in the lipid dynamics when Menk interacts with the bicellar systems. (2)H NMR experiments showed a disordering effect of Menk on the lipid chains in all the bicelles except Bic/PG, whereas the study of the choline headgroups indicated a decreased order of the lipids only in Bic/PE and Bic/PG. Our results suggest that the insertion depth of Menk into bicelles is modulated by their composition, more specifically by the balance between hydrophobic and electrostatic interactions. Menk would be buried at the lipid polar/apolar interface, the depth of penetration into the hydrophobic membrane core following the scaling Bic > Bic/PE > Bic/PS at the slightly acidic pH used in this study. The peptide would not insert into the bilayer core of Bic/PG and would rather remain at the surface.
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Affiliation(s)
- Isabelle Marcotte
- Département de Chimie, Centre de Recherche en Sciences et Ingénierie des Macromolécules, Université Laval, Québec, Québec, Canada, G1K 7P4
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11
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Zandomeneghi G, Williamson PTF, Hunkeler A, Meier BH. Switched-angle spinning applied to bicelles containing phospholipid-associated peptides. JOURNAL OF BIOMOLECULAR NMR 2003; 25:125-132. [PMID: 12652121 DOI: 10.1023/a:1022244025351] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In a model study, the proton NMR spectrum of the opioid pentapeptide leucine-enkephalin associated with bicelles is investigated. The spectral resolution for a static sample is limited due to the large number of anisotropic interactions, in particular strong proton-proton couplings, but resolution is greatly improved by magic-angle sample spinning. Here we present two-dimensional switched-angle spinning NMR experiments, which correlate the high-resolution spectrum of the membrane-bound peptide under magic-angle spinning with its anisotropic spectrum, leading to well-resolved spectra. The two-dimensional spectrum allows the exploitation of the high resolution of the isotropic spectrum, while retaining the structural information imparted by the anisotropic interactions in the static spectrum. Furthermore, switched-angle spinning techniques are demonstrated that allow one to record the proton spectrum of ordered bicellar phases as a function of the angle between the rotor axis and the magnetic field direction, thereby scaling the dipolar interactions by a predefined factor.
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12
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Amodeo P, Guerrini R, Picone D, Salvadori S, Spadaccini R, Tancredi T, Temussi PA. Solution structure of nociceptin peptides. J Pept Sci 2002; 8:497-509. [PMID: 12371703 DOI: 10.1002/psc.412] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2002] [Accepted: 05/14/2002] [Indexed: 11/10/2022]
Abstract
Peptides embedded in the sequence of pre-pro-nociceptin, i.e. nociceptin, nocistatin and orphanin FQ2, have shed light on the complexity of the mechanisms involving the peptide hormones related to pain and have opened up new perspectives for the clinical treatment of pain. The design of new ligands with high selectivity and bioavailability, in particular for ORL1, is important both for the elucidation and control of the physiological role of the receptor and for their therapeutic importance. The failure to obtain agonists and antagonists when using, for nociceptin, the same substitutions that are successful for opioids, and the conformational flexibility of them all, justify systematic efforts to study the solution conformation under conditions as close as possible to their natural environment. Structural studies of linear peptides in solution are hampered by their high flexibility. A direct structural study of the complex between a peptide and its receptor would overcome this difficulty, but such a study is not easy since opioid receptors are membrane proteins. Thus, conformational studies of lead peptides in solution are still important for drug design. This review deals with conformational studies of natural pre-nociceptin peptides in several solvents that mimic in part the different environments in which the peptides exert their action. None of the structural investigations yielded a completely reliable bioactive conformation, but the global conformation of the peptides in biomimetic environments can shed light on their interaction with receptors.
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Affiliation(s)
- Pietro Amodeo
- Istituto di Chimica Biomolecolare del CNR, Pozzuoli, Italy
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13
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Affiliation(s)
- C R Sanders
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106-4970, USA.
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14
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Abstract
Lipid-bilayer membranes are key objects in drug research in relation to (i) interaction of drugs with membrane-bound receptors, (ii) drug targeting, penetration, and permeation of cell membranes, and (iii) use of liposomes in micro-encapsulation technologies for drug delivery. Rational design of new drugs and drug-delivery systems therefore requires insight into the physical properties of lipid-bilayer membranes. This mini-review provides a perspective on the current view of lipid-bilayer structure and dynamics based on information obtained from a variety of recent experimental and theoretical studies. Special attention is paid to trans-bilayer structure, lateral molecular organization of the lipid bilayer, lipid-mediated protein assembly, and lipid-bilayer permeability. It is argued that lipids play a major role in lipid membrane-organization and functionality.
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Affiliation(s)
- O G Mouritsen
- Department of Chemistry, Technical University of Denmark, Lyngby.
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15
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Losonczi JA, Prestegard JH. Improved dilute bicelle solutions for high-resolution NMR of biological macromolecules. JOURNAL OF BIOMOLECULAR NMR 1998; 12:447-451. [PMID: 9835051 DOI: 10.1023/a:1008302110884] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Dissolving biological macromolecules in dilute bicelle solutions, which form oriented liquid crystals in the presence of a magnetic field, permits measurement of anisotropic spin interactions such as dipolar couplings [Tjandra, N. and Bax, A., Science, 278, 1111-1114]. However, the lifetimes and temperature ranges of orientation for these samples are critically dependent on sample composition and experimental conditions. This paper demonstrates that doping dilute bicelle solutions with small amounts of charged amphiphiles substantially improves the stability and degree of alignment, as well as extends the temperature range of orientation for these systems. An explanation of the dependence of bicelle aggregation on sample composition is proposed based on the DLVO theory of colloids.
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Affiliation(s)
- J A Losonczi
- Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA
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16
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Nishimura K, Naito A, Tuzi S, Saitô H, Hashimoto C, Aida M. Determination of the Three-Dimensional Structure of Crystalline Leu-Enkephalin Dihydrate Based on Six Sets of Accurately Determined Interatomic Distances from 13C-REDOR NMR and the Conformation-Dependent 13C Chemical Shifts. J Phys Chem B 1998. [DOI: 10.1021/jp981683w] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Katsuyuki Nishimura
- Department of Life Science, Himeji Institute of Technology, Harima Science Garden City, Kamigori, Hyogo 678-1297, Japan
| | - Akira Naito
- Department of Life Science, Himeji Institute of Technology, Harima Science Garden City, Kamigori, Hyogo 678-1297, Japan
| | - Satoru Tuzi
- Department of Life Science, Himeji Institute of Technology, Harima Science Garden City, Kamigori, Hyogo 678-1297, Japan
| | - Hazime Saitô
- Department of Life Science, Himeji Institute of Technology, Harima Science Garden City, Kamigori, Hyogo 678-1297, Japan
| | - Chikao Hashimoto
- Department of Chemistry, The Jikei University School of Medicine, Kokuryo-cho, Chofu-shi, Tokyo 182-0022, Japan
| | - Misako Aida
- Biophysics Division, National Cancer Center Research Institute, Tukiji 5-chome, Chuo-ku, Tokyo 104-0045, Japan
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