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Parker E, Haberichter SL, Lollar P. Subunit Flexibility of Multimeric von Willebrand Factor/Factor VIII Complexes. ACS OMEGA 2022; 7:31183-31196. [PMID: 36092565 PMCID: PMC9453814 DOI: 10.1021/acsomega.2c03389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
Von Willebrand factor (VWF) is a plasma glycoprotein that participates in platelet adhesion and aggregation and serves as a carrier for blood coagulation factor VIII (fVIII). Plasma VWF consists of a population of multimers that range in molecular weight from ∼ 0.55 MDa to greater than 10 MDa. The VWF multimer consists of a variable number of concatenated disulfide-linked ∼275 kDa subunits. We fractionated plasma-derived human VWF/fVIII complexes by size-exclusion chromatography at a pH of 7.4 and subjected them to analysis by sodium dodecyl sulfate agarose gel electrophoresis, sedimentation velocity analytical ultracentrifugation (SV AUC), dynamic light scattering (DLS), and multi-angle light scattering (MALS). Weight-average molecular weights, M w, were independently measured by MALS and by application of the Svedberg equation to SV AUC and DLS measurements. Estimates of the Mark-Houwink-Kuhn-Sakurada exponents , αs, and αD describing the functional relationship between the z-average radius of gyration, , weight-average sedimentation coefficient, s w, z-average diffusion coefficient, D z , and M w were consistent with a random coil conformation of the VWF multimer. Ratios of to the z-average hydrodynamic radius, , estimated by DLS, were calculated across an M w range from 2 to 5 MDa. When compared to values calculated for a semi-flexible, wormlike chain, these ratios were consistent with a contour length over 1000-fold greater than the persistence length. These results indicate a high degree of flexibility between domains of the VWF subunit.
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Affiliation(s)
- Ernest
T. Parker
- Aflac
Cancer and Blood Disorders Center, Children’s Healthcare of
Atlanta; Department of Pediatrics, Emory
University, Atlanta Georgia 30322, United States
| | - Sandra L. Haberichter
- Diagnostic
Laboratories and Blood Research Institute, Versiti, Milwaukee, Wisconsin 53201-2178, United States
- Pediatric
Hematology/Oncology, Medical College of
Wisconsin, Milwaukee, Wisconsin 53226, United States
- Children’s
Research Institute, Children’s Hospital
of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Pete Lollar
- Aflac
Cancer and Blood Disorders Center, Children’s Healthcare of
Atlanta; Department of Pediatrics, Emory
University, Atlanta Georgia 30322, United States
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Ballance S, Lu Y, Zobel H, Rieder A, Knutsen SH, Dinu VT, Christensen BE, Ulset AS, Schmid M, Maina N, Potthast A, Schiehser S, Ellis PR, Harding SE. Inter-laboratory analysis of cereal beta-glucan extracts of nutritional importance: An evaluation of different methods for determining weight-average molecular weight and molecular weight distribution. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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3
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Structural and Biophysical Characterization of the HCV E1E2 Heterodimer for Vaccine Development. Viruses 2021; 13:v13061027. [PMID: 34072451 PMCID: PMC8227786 DOI: 10.3390/v13061027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 02/07/2023] Open
Abstract
An effective vaccine for the hepatitis C virus (HCV) is a major unmet medical and public health need, and it requires an antigen that elicits immune responses to multiple key conserved epitopes. Decades of research have generated a number of vaccine candidates; based on these data and research through clinical development, a vaccine antigen based on the E1E2 glycoprotein complex appears to be the best choice. One bottleneck in the development of an E1E2-based vaccine is that the antigen is challenging to produce in large quantities and at high levels of purity and antigenic/functional integrity. This review describes the production and characterization of E1E2-based vaccine antigens, both membrane-associated and a novel secreted form of E1E2, with a particular emphasis on the major challenges facing the field and how those challenges can be addressed.
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Conformation of the von Willebrand factor/factor VIII complex in quasi-static flow. J Biol Chem 2021; 296:100420. [PMID: 33600794 PMCID: PMC8005835 DOI: 10.1016/j.jbc.2021.100420] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/11/2021] [Indexed: 12/18/2022] Open
Abstract
Von Willebrand factor (VWF) is a plasma glycoprotein that circulates noncovalently bound to blood coagulation factor VIII (fVIII). VWF is a population of multimers composed of a variable number of ∼280 kDa monomers that is activated in shear flow to bind collagen and platelet glycoprotein Ibα. Electron microscopy, atomic force microscopy, small-angle neutron scattering, and theoretical studies have produced a model in which the conformation of VWF under static conditions is a compact, globular “ball-of-yarn,” implying strong, attractive forces between monomers. We performed sedimentation velocity (SV) analytical ultracentrifugation measurements on unfractionated VWF/fVIII complexes. There was a 20% per mg/ml decrease in the weight-average sedimentation coefficient, sw, in contrast to the ∼1% per mg/ml decrease observed for compact globular proteins. SV and dynamic light scattering measurements were performed on VWF/fVIII complexes fractionated by size-exclusion chromatography to obtain sw values and z-average diffusion coefficients, Dz. Molecular weights estimated using these values in the Svedberg equation ranged from 1.7 to 4.1 MDa. Frictional ratios calculated from Dz and molecular weights ranged from 2.9 to 3.4, in contrast to values of 1.1–1.3 observed for globular proteins. The Mark–Houwink–Kuhn–Sakurada scaling relationships between sw, Dz and molecular weight, s=k′Mas and D=k″MaD, yielded estimates of 0.51 and –0.49 for as and aD, respectively, consistent with a random coil, in contrast to the as value of 0.65 observed for globular proteins. These results indicate that interactions between monomers are weak or nonexistent and that activation of VWF is intramonomeric.
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Analytical ultracentrifuge: an ideal tool for characterization of non-coding RNAs. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:809-818. [PMID: 33067686 DOI: 10.1007/s00249-020-01470-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/26/2020] [Accepted: 10/05/2020] [Indexed: 12/25/2022]
Abstract
Analytical ultracentrifugation (AUC) has emerged as a robust and reliable technique for biomolecular characterization with extraordinary sensitivity. AUC is widely used to study purity, conformational changes, biomolecular interactions, and stoichiometry. Furthermore, AUC is used to determine the molecular weight of biomolecules such as proteins, carbohydrates, and DNA and RNA. Due to the multifaceted role(s) of non-coding RNAs from viruses, prokaryotes, and eukaryotes, research aimed at understanding the structure-function relationships of non-coding RNAs is rapidly increasing. However, due to their large size, flexibility, complicated secondary structures, and conformations, structural studies of non-coding RNAs are challenging. In this review, we are summarizing the application of AUC to evaluate the homogeneity, interactions, and conformational changes of non-coding RNAs from adenovirus as well as from Murray Valley, Powassan, and West Nile viruses. We also discuss the application of AUC to characterize eukaryotic long non-coding RNAs, Xist, and HOTAIR. These examples highlight the significant role AUC can play in facilitating the structural determination of non-coding RNAs and their complexes.
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Grube M, Dinu V, Lindemann H, Pielenz F, Festag G, Schubert US, Heinze T, Harding S, Nischang I. Polysaccharide valproates: Structure - property relationships in solution. Carbohydr Polym 2020; 246:116652. [PMID: 32747284 DOI: 10.1016/j.carbpol.2020.116652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/07/2020] [Accepted: 06/15/2020] [Indexed: 12/30/2022]
Abstract
Polysaccharides are promising macromolecular platforms for use in the life sciences. Here, bioactive cellulose, pullulan, and dextran valproates are characterized hydrodynamically by sedimentation velocity and thermodynamically by sedimentation equilibrium analytical ultracentrifugation. Using sedimentation-diffusion analysis of sedimentation velocity experiments by numerical solution of the Lamm equation enabled the calculation of sedimentation and diffusion coefficients, and consequently molar masses. Sedimentation equilibrium experiments were then also used to determine the average molar masses. The corresponding set of data, with independently performed self-diffusion measurements by nuclear magnetic resonance spectroscopy, and together with size exclusion chromatography molar masses by coupling to refractive index-, viscometric-, and multi-angle laser light scattering detection, were subsequently correlated to each other by the hydrodynamic invariant and sedimentation parameter. We assess statistically most relevant average values of the molar masses of these polysaccharide valproates with relevant macromolecular conformational characteristics.
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Affiliation(s)
- Mandy Grube
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Vlad Dinu
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, United Kingdom
| | - Henry Lindemann
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Friederike Pielenz
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany
| | - Grit Festag
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Thomas Heinze
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Stephen Harding
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, United Kingdom
| | - Ivo Nischang
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany; Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany.
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Nirwan N, Singh P, Mishra GG, Johnson CM, Szczelkun MD, Inoue K, Vinothkumar KR, Saikrishnan K. Hexameric assembly of the AAA+ protein McrB is necessary for GTPase activity. Nucleic Acids Res 2019; 47:868-882. [PMID: 30521042 PMCID: PMC6344862 DOI: 10.1093/nar/gky1170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/09/2018] [Indexed: 01/23/2023] Open
Abstract
McrBC is one of the three modification-dependent restriction enzymes encoded by the Escherichia coli K12 chromosome. Amongst restriction enzymes, McrBC and its close homologues are unique in employing the AAA+ domain for GTP hydrolysis-dependent activation of DNA cleavage. The GTPase activity of McrB is stimulated by the endonuclease subunit McrC. It had been reported previously that McrB and McrC subunits oligomerise together into a high molecular weight species. Here we conclusively demonstrate using size exclusion chromatography coupled multi-angle light scattering (SEC-MALS) and images obtained by electron cryomicroscopy that McrB exists as a hexamer in solution. Furthermore, based on SEC-MALS and SAXS analyses of McrBC and the structure of McrB, we propose that McrBC is a complex of two McrB hexamers bridged by two subunits of McrC, and that the complete assembly of this complex is integral to its enzymatic activity. We show that the nucleotide-dependent oligomerisation of McrB precedes GTP hydrolysis. Mutational studies show that, unlike other AAA+ proteins, the catalytic Walker B aspartate is required for oligomerisation.
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Affiliation(s)
- Neha Nirwan
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Pratima Singh
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Gyana Gourab Mishra
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | | | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Katsuaki Inoue
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0DE, UK
| | | | - Kayarat Saikrishnan
- Division of Biology, Indian Institute of Science Education and Research, Pune 411008, India
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Wycisk K, Tarczewska A, Kaus-Drobek M, Dadlez M, Hołubowicz R, Pietras Z, Dziembowski A, Taube M, Kozak M, Orłowski M, Ożyhar A. Intrinsically disordered N-terminal domain of the Helicoverpa armigera Ultraspiracle stabilizes the dimeric form via a scorpion-like structure. J Steroid Biochem Mol Biol 2018; 183:167-183. [PMID: 29944921 DOI: 10.1016/j.jsbmb.2018.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/18/2018] [Accepted: 06/18/2018] [Indexed: 12/31/2022]
Abstract
Nuclear receptors (NRs) are a family of ligand-dependent transcription factors activated by lipophilic compounds. NRs share a common structure comprising three domains: a variable N-terminal domain (NTD), a highly conserved globular DNA-binding domain and a ligand-binding domain. There are numerous papers describing the molecular details of the latter two globular domains. However, very little is known about the structure-function relationship of the NTD, especially as an intrinsically disordered fragment of NRs that may influence the molecular properties and, in turn, the function of globular domains. Here, we investigated whether and how an intrinsically disordered NTD consisting of 58 amino acid residues affects the functions of the globular domains of the Ultraspiracle protein from Helicoverpa armigera (HaUsp). The role of the NTD was examined for two well-known and easily testable NR functions, i.e., interactions with specific DNA sequences and dimerization. Electrophoretic mobility shift assays showed that the intrinsically disordered NTD influences the interaction of HaUsp with specific DNA sequences, apparently by destabilization of HaUsp-DNA complexes. On the other hand, multi-angle light scattering and sedimentation velocity analytical ultracentrifugation revealed that the NTD acts as a structural element that stabilizes HaUsp homodimers. Molecular models based on small-angle X-ray scattering indicate that the intrinsically disordered NTD may exert its effects on the tested HaUsp functions by forming an unexpected scorpion-like structure, in which the NTD bends towards the ligand-binding domain in each subunit of the HaUsp homodimer. This structure may be crucial for specific NTD-dependent regulation of the functions of globular domains in NRs.
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Affiliation(s)
- Krzysztof Wycisk
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Aneta Tarczewska
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Magdalena Kaus-Drobek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Michał Dadlez
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Rafał Hołubowicz
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Zbigniew Pietras
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Andrzej Dziembowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Michał Taube
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Maciej Kozak
- Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Marek Orłowski
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Andrzej Ożyhar
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
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9
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Rambo RP. Considerations for Sample Preparation Using Size-Exclusion Chromatography for Home and Synchrotron Sources. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1009:31-45. [PMID: 29218552 PMCID: PMC6126186 DOI: 10.1007/978-981-10-6038-0_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The success of a SAXS experiment for structural investigations depends on two precise measurements, the sample and the buffer background. Buffer matching between the sample and background can be achieved using dialysis methods but in biological SAXS of monodisperse systems, sample preparation is routinely being performed with size exclusion chromatography (SEC). SEC is the most reliable method for SAXS sample preparation as the method not only purifies the sample for SAXS but also almost guarantees ideal buffer matching. Here, I will highlight the use of SEC for SAXS sample preparation and demonstrate using example proteins that SEC purification does not always provide for ideal samples. Scrutiny of the SEC elution peak using quasi-elastic and multi-angle light scattering techniques can reveal hidden features (heterogeneity) of the sample that should be considered during SAXS data analysis. In some cases, sample heterogeneity can be controlled using a small molecule additive and I outline a simple additive screening method for sample preparation.
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Affiliation(s)
- Robert P Rambo
- Diamond Light Source Ltd., Harwell Science & Innovation Campus, Didcot, OX11 0DE, UK.
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Chaturvedi SK, Zhao H, Schuck P. Sedimentation of Reversibly Interacting Macromolecules with Changes in Fluorescence Quantum Yield. Biophys J 2017; 112:1374-1382. [PMID: 28402880 DOI: 10.1016/j.bpj.2017.02.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/10/2017] [Accepted: 02/21/2017] [Indexed: 11/29/2022] Open
Abstract
Sedimentation velocity analytical ultracentrifugation with fluorescence detection has emerged as a powerful method for the study of interacting systems of macromolecules. It combines picomolar sensitivity with high hydrodynamic resolution, and can be carried out with photoswitchable fluorophores for multicomponent discrimination, to determine the stoichiometry, affinity, and shape of macromolecular complexes with dissociation equilibrium constants from picomolar to micromolar. A popular approach for data interpretation is the determination of the binding affinity by isotherms of weight-average sedimentation coefficients sw. A prevailing dogma in sedimentation analysis is that the weight-average sedimentation coefficient from the transport method corresponds to the signal- and population-weighted average of all species. We show that this does not always hold true for systems that exhibit significant signal changes with complex formation-properties that may be readily encountered in practice, e.g., from a change in fluorescence quantum yield. Coupled transport in the reaction boundary of rapidly reversible systems can make significant contributions to the observed migration in a way that cannot be accounted for in the standard population-based average. Effective particle theory provides a simple physical picture for the reaction-coupled migration process. On this basis, we develop a more general binding model that converges to the well-known form of sw with constant signals, but can account simultaneously for hydrodynamic cotransport in the presence of changes in fluorescence quantum yield. We believe this will be useful when studying interacting systems exhibiting fluorescence quenching, enhancement, or Förster resonance energy transfer with transport methods.
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Affiliation(s)
- Sumit K Chaturvedi
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland.
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Structural studies of RNA-protein complexes: A hybrid approach involving hydrodynamics, scattering, and computational methods. Methods 2016; 118-119:146-162. [PMID: 27939506 DOI: 10.1016/j.ymeth.2016.12.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/01/2016] [Accepted: 12/05/2016] [Indexed: 01/01/2023] Open
Abstract
The diverse functional cellular roles played by ribonucleic acids (RNA) have emphasized the need to develop rapid and accurate methodologies to elucidate the relationship between the structure and function of RNA. Structural biology tools such as X-ray crystallography and Nuclear Magnetic Resonance are highly useful methods to obtain atomic-level resolution models of macromolecules. However, both methods have sample, time, and technical limitations that prevent their application to a number of macromolecules of interest. An emerging alternative to high-resolution structural techniques is to employ a hybrid approach that combines low-resolution shape information about macromolecules and their complexes from experimental hydrodynamic (e.g. analytical ultracentrifugation) and solution scattering measurements (e.g., solution X-ray or neutron scattering), with computational modeling to obtain atomic-level models. While promising, scattering methods rely on aggregation-free, monodispersed preparations and therefore the careful development of a quality control pipeline is fundamental to an unbiased and reliable structural determination. This review article describes hydrodynamic techniques that are highly valuable for homogeneity studies, scattering techniques useful to study the low-resolution shape, and strategies for computational modeling to obtain high-resolution 3D structural models of RNAs, proteins, and RNA-protein complexes.
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