1
|
Ding EA, Kumar S. Neurofilament Biophysics: From Structure to Biomechanics. Mol Biol Cell 2024; 35:re1. [PMID: 38598299 DOI: 10.1091/mbc.e23-11-0438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024] Open
Abstract
Neurofilaments (NFs) are multisubunit, neuron-specific intermediate filaments consisting of a 10-nm diameter filament "core" surrounded by a layer of long intrinsically disordered protein (IDP) "tails." NFs are thought to regulate axonal caliber during development and then stabilize the mature axon, with NF subunit misregulation, mutation, and aggregation featuring prominently in multiple neurological diseases. The field's understanding of NF structure, mechanics, and function has been deeply informed by a rich variety of biochemical, cell biological, and mouse genetic studies spanning more than four decades. These studies have contributed much to our collective understanding of NF function in axonal physiology and disease. In recent years, however, there has been a resurgence of interest in NF subunit proteins in two new contexts: as potential blood- and cerebrospinal fluid-based biomarkers of neuronal damage, and as model IDPs with intriguing properties. Here, we review established principles and more recent discoveries in NF structure and function. Where possible, we place these findings in the context of biophysics of NF assembly, interaction, and contributions to axonal mechanics.
Collapse
Affiliation(s)
- Erika A Ding
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Sanjay Kumar
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158
| |
Collapse
|
2
|
Kravikass M, Koren G, Saleh OA, Beck R. From isolated polyelectrolytes to star-like assemblies: the role of sequence heterogeneity on the statistical structure of the intrinsically disordered neurofilament-low tail domain. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2024; 47:13. [PMID: 38358563 PMCID: PMC10869404 DOI: 10.1140/epje/s10189-024-00409-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 02/02/2024] [Indexed: 02/16/2024]
Abstract
Intrinsically disordered proteins (IDPs) are a subset of proteins that lack stable secondary structure. Given their polymeric nature, previous mean-field approximations have been used to describe the statistical structure of IDPs. However, the amino-acid sequence heterogeneity and complex intermolecular interaction network have significantly impeded the ability to get proper approximations. One such case is the intrinsically disordered tail domain of neurofilament low (NFLt), which comprises a 50 residue-long uncharged domain followed by a 96 residue-long negatively charged domain. Here, we measure two NFLt variants to identify the impact of the NFLt two main subdomains on its complex interactions and statistical structure. Using synchrotron small-angle x-ray scattering, we find that the uncharged domain of the NFLt induces attractive interactions that cause it to self-assemble into star-like polymer brushes. On the other hand, when the uncharged domain is truncated, the remaining charged N-terminal domains remain isolated in solution with typical polyelectrolyte characteristics. We further discuss how competing long- and short-ranged interactions within the polymer brushes dominate their ensemble structure and, in turn, their implications on previously observed phenomena in NFL native and diseased states.
Collapse
Affiliation(s)
- Mathar Kravikass
- School of Physics and Astronomy, The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
- The Center of Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel
| | - Gil Koren
- School of Physics and Astronomy, The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
- The Center of Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel
| | - Omar A Saleh
- Materials Department, Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, USA
- Physics Department, University of California, Santa Barbara, USA
| | - Roy Beck
- School of Physics and Astronomy, The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel.
- The Center of Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
3
|
Koren G, Meir S, Holschuh L, Mertens HDT, Ehm T, Yahalom N, Golombek A, Schwartz T, Svergun DI, Saleh OA, Dzubiella J, Beck R. Intramolecular structural heterogeneity altered by long-range contacts in an intrinsically disordered protein. Proc Natl Acad Sci U S A 2023; 120:e2220180120. [PMID: 37459524 PMCID: PMC10372579 DOI: 10.1073/pnas.2220180120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 06/02/2023] [Indexed: 07/20/2023] Open
Abstract
Short-range interactions and long-range contacts drive the 3D folding of structured proteins. The proteins' structure has a direct impact on their biological function. However, nearly 40% of the eukaryotes proteome is composed of intrinsically disordered proteins (IDPs) and protein regions that fluctuate between ensembles of numerous conformations. Therefore, to understand their biological function, it is critical to depict how the structural ensemble statistics correlate to the IDPs' amino acid sequence. Here, using small-angle X-ray scattering and time-resolved Förster resonance energy transfer (trFRET), we study the intramolecular structural heterogeneity of the neurofilament low intrinsically disordered tail domain (NFLt). Using theoretical results of polymer physics, we find that the Flory scaling exponent of NFLt subsegments correlates linearly with their net charge, ranging from statistics of ideal to self-avoiding chains. Surprisingly, measuring the same segments in the context of the whole NFLt protein, we find that regardless of the peptide sequence, the segments' structural statistics are more expanded than when measured independently. Our findings show that while polymer physics can, to some level, relate the IDP's sequence to its ensemble conformations, long-range contacts between distant amino acids play a crucial role in determining intramolecular structures. This emphasizes the necessity of advanced polymer theories to fully describe IDPs ensembles with the hope that it will allow us to model their biological function.
Collapse
Affiliation(s)
- Gil Koren
- The School of Physics and Astronomy, Department of Condensed Matter, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
| | - Sagi Meir
- The School of Physics and Astronomy, Department of Condensed Matter, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
| | - Lennard Holschuh
- Applied Theoretical Physics-Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universit Freiburg, FreiburgD-79104, Germany
| | | | - Tamara Ehm
- The School of Physics and Astronomy, Department of Condensed Matter, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
- Faculty of Physics and Center for NanoScience, Ludwig-Maximilians-Universität, MünchenD-80539, Germany
| | - Nadav Yahalom
- The Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences and Tel Aviv University Center for Light–Matter Interaction, Tel Aviv University, Tel Aviv6997801, Israel
| | - Adina Golombek
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences and Tel Aviv University Center for Light–Matter Interaction, Tel Aviv University, Tel Aviv6997801, Israel
| | - Tal Schwartz
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences and Tel Aviv University Center for Light–Matter Interaction, Tel Aviv University, Tel Aviv6997801, Israel
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg22607, Germany
| | - Omar A. Saleh
- BMSE Program, University of California, Santa Barbara, CA93110
- Materials Department, University of California, Santa Barbara, CA93110
| | - Joachim Dzubiella
- Applied Theoretical Physics-Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universit Freiburg, FreiburgD-79104, Germany
- Cluster of Excellence livMatS @ FIT–Freiburg Center for Interactive Materials and Bioinspired Technologies, Albert-Ludwigs-Universit Freiburg, FreiburgD-79104, Germany
| | - Roy Beck
- The School of Physics and Astronomy, Department of Condensed Matter, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv69978, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv69978, Israel
| |
Collapse
|
4
|
Jacoby G, Segal Asher M, Ehm T, Abutbul Ionita I, Shinar H, Azoulay-Ginsburg S, Zemach I, Koren G, Danino D, Kozlov MM, Amir RJ, Beck R. Order from Disorder with Intrinsically Disordered Peptide Amphiphiles. J Am Chem Soc 2021; 143:11879-11888. [PMID: 34310121 PMCID: PMC8397319 DOI: 10.1021/jacs.1c06133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Indexed: 01/02/2023]
Abstract
Amphiphilic molecules and their self-assembled structures have long been the target of extensive research due to their potential applications in fields ranging from materials design to biomedical and cosmetic applications. Increasing demands for functional complexity have been met with challenges in biochemical engineering, driving researchers to innovate in the design of new amphiphiles. An emerging class of molecules, namely, peptide amphiphiles, combines key advantages and circumvents some of the disadvantages of conventional phospholipids and block copolymers. Herein, we present new peptide amphiphiles composed of an intrinsically disordered peptide conjugated to two variants of hydrophobic dendritic domains. These molecules, termed intrinsically disordered peptide amphiphiles (IDPA), exhibit a sharp pH-induced micellar phase-transition from low-dispersity spheres to extremely elongated worm-like micelles. We present an experimental characterization of the transition and propose a theoretical model to describe the pH-response. We also present the potential of the shape transition to serve as a mechanism for the design of a cargo hold-and-release application. Such amphiphilic systems demonstrate the power of tailoring the interactions between disordered peptides for various stimuli-responsive biomedical applications.
Collapse
Affiliation(s)
- Guy Jacoby
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
| | - Merav Segal Asher
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
- Raymond
& Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tamara Ehm
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
- Faculty
of Physics and Center for NanoScience, Ludwig-Maximilians-Universität, München D-80539, Germany
| | - Inbal Abutbul Ionita
- CryoEM
Laboratory of Soft Matter, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Hila Shinar
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
| | - Salome Azoulay-Ginsburg
- Raymond
& Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ido Zemach
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
| | - Gil Koren
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
| | - Dganit Danino
- CryoEM
Laboratory of Soft Matter, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Guangdong-Technion
Israel Institute of Technology, Shantou, Guangdong Province 515063, China
| | - Michael M. Kozlov
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- Sackler School
of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roey J. Amir
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
- Raymond
& Beverly Sackler School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roy Beck
- Raymond
& Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for Physics & Chemistry of Living Systems, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Center for NanoTechnology & NanoScience, Tel Aviv Univeristy, Tel Aviv 6997801, Israel
| |
Collapse
|
5
|
Theoretical Modeling of Chemical Equilibrium in Weak Polyelectrolyte Layers on Curved Nanosystems. Polymers (Basel) 2020; 12:polym12102282. [PMID: 33027995 PMCID: PMC7601300 DOI: 10.3390/polym12102282] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022] Open
Abstract
Surface functionalization with end-tethered weak polyelectrolytes (PE) is a versatile way to modify and control surface properties, given their ability to alter their degree of charge depending on external cues like pH and salt concentration. Weak PEs find usage in a wide range of applications, from colloidal stabilization, lubrication, adhesion, wetting to biomedical applications such as drug delivery and theranostics applications. They are also ubiquitous in many biological systems. Here, we present an overview of some of the main theoretical methods that we consider key in the field of weak PE at interfaces. Several applications involving engineered nanoparticles, synthetic and biological nanopores, as well as biological macromolecules are discussed to illustrate the salient features of systems involving weak PE near an interface or under (nano)confinement. The key feature is that by confining weak PEs near an interface the degree of charge is different from what would be expected in solution. This is the result of the strong coupling between structural organization of weak PE and its chemical state. The responsiveness of engineered and biological nanomaterials comprising weak PE combined with an adequate level of modeling can provide the keys to a rational design of smart nanosystems.
Collapse
|
6
|
Morgan IL, Avinery R, Rahamim G, Beck R, Saleh OA. Glassy Dynamics and Memory Effects in an Intrinsically Disordered Protein Construct. PHYSICAL REVIEW LETTERS 2020; 125:058001. [PMID: 32794838 DOI: 10.1103/physrevlett.125.058001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
Glassy, nonexponential relaxations in globular proteins are typically attributed to conformational behaviors that are missing from intrinsically disordered proteins. Yet, we show that single molecules of a disordered-protein construct display two signatures of glassy dynamics, logarithmic relaxations and a Kovacs memory effect, in response to changes in applied tension. We attribute this to the presence of multiple independent local structures in the chain, which we corroborate with a model that correctly predicts the force dependence of the relaxation. The mechanism established here likely applies to other disordered proteins.
Collapse
Affiliation(s)
- Ian L Morgan
- BMSE Program, University of California, Santa Barbara, California 93106, USA
| | - Ram Avinery
- The Raymond and Beverly Sackler School of Physics and Astronomy and The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Gil Rahamim
- The Raymond and Beverly Sackler School of Physics and Astronomy and The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Roy Beck
- The Raymond and Beverly Sackler School of Physics and Astronomy and The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Omar A Saleh
- BMSE Program, University of California, Santa Barbara, California 93106, USA
- Materials Department, University of California, Santa Barbara, California 93106, USA
| |
Collapse
|
7
|
Vickers JC, King AE, McCormack GH, Bindoff AD, Adlard PA. Iron is increased in the brains of ageing mice lacking the neurofilament light gene. PLoS One 2019; 14:e0224169. [PMID: 31644557 PMCID: PMC6808381 DOI: 10.1371/journal.pone.0224169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 10/06/2019] [Indexed: 11/18/2022] Open
Abstract
There has been strong interest in the role of metals in neurodegeneration, and how ageing may predispose the brain to related diseases such as Alzheimer’s disease. Recent work has also highlighted a potential interaction between different metal species and various components of the cytoskeletal network in the brain, which themselves have a reported role in age-related degenerative disease and other neurological disorders. Neurofilaments are one such class of intermediate filament protein that have a demonstrated capacity to bind and utilise cation species. In this study, we investigated the consequences of altering the neurofilamentous network on metal ion homeostasis by examining neurofilament light (NFL) gene knockout mice, relative to wildtype control animals, at adulthood (5 months of age) and advanced age (22 months). Inductively coupled plasma mass spectroscopy demonstrated that the concentrations of iron (Fe), copper (Cu) and zinc (Zn) varied across brain regions and peripheral nerve samples. Zn and Fe showed statistically significant interactions between genotype and age, as well as between genotype and region, and Cu demonstrated a genotype and region interaction. The most substantial difference between genotypes was found in Fe in the older animals, where, across many regions examined, there was elevated Fe in the NFL knockout mice. This data indicates a potential relationship between the neurofilamentous cytoskeleton and the processing and/or storage of Fe through ageing.
Collapse
Affiliation(s)
- James C. Vickers
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
- * E-mail:
| | - Anna E. King
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
| | - Graeme H. McCormack
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
| | - Aidan D. Bindoff
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
| | - Paul A. Adlard
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| |
Collapse
|
8
|
Chakraborty I, Rahamim G, Avinery R, Roichman Y, Beck R. Nanoparticle Mobility over a Surface as a Probe for Weak Transient Disordered Peptide-Peptide Interactions. NANO LETTERS 2019; 19:6524-6534. [PMID: 31456409 DOI: 10.1021/acs.nanolett.9b02764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Weak interactions form the core basis of a vast number of biological processes, in particular, those involving intrinsically disordered proteins. Here, we establish a new technique capable of probing these weak interactions between synthetic unfolded polypeptides using a convenient yet efficient, quantitative method based on single particle tracking of peptide-coated gold nanoparticles over peptide-coated surfaces. We demonstrate that our technique is sensitive enough to observe the influence of a single amino acid mutation on the transient peptide-peptide interactions. Furthermore, the effects of buffer salinity, which are expected to alter weak electrostatic interactions, are also readily detected and examined in detail. The method presented here has the potential to evaluate, in a high-throughput manner, weak interactions for a wide range of disordered proteins, polypeptides, and other biomolecules.
Collapse
Affiliation(s)
| | - Gil Rahamim
- School of Physics and Astronomy , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Ram Avinery
- School of Physics and Astronomy , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Yael Roichman
- School of Chemistry , Tel Aviv University , Tel Aviv 6997801 , Israel
- School of Physics and Astronomy , Tel Aviv University , Tel Aviv 6997801 , Israel
| | - Roy Beck
- School of Physics and Astronomy , Tel Aviv University , Tel Aviv 6997801 , Israel
| |
Collapse
|
9
|
Malik SA, Mondal S, Atreya HS. Enhanced stability of an intrinsically disordered protein against proteolytic cleavage through interactions with silver nanoparticles. RSC Adv 2019; 9:28746-28753. [PMID: 35529627 PMCID: PMC9071183 DOI: 10.1039/c9ra05514b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/02/2019] [Indexed: 11/21/2022] Open
Abstract
Intrinsically disordered proteins (IDPs), being sensitive to proteolytic degradation both in vitro and in vivo, can be stabilized by the interactions with various binding partners. Here, we show for the first time that silver nanoparticles (AgNPs) have the ability to enhance the half-life of an IDP, thereby rendering it stable for a month against proteolytic degradation. The conjugate of the unstructured linker domain of human insulin-like growth factor binding protein-2 (L-hIGFBP2) with 10 nm citrate-capped AgNPs was studied using two-dimensional NMR spectroscopy and other biophysical techniques. Our studies reveal the extent and nature of residue-specific interactions of the IDP with AgNPs. These interactions mask proteolysis-prone sites of the IDP and stabilize it. This study opens new avenues for the design of appropriate nanoparticles targeting IDPs and for storage, stabilization and delivery of IDPs into cells in a stable form.
Collapse
Affiliation(s)
- Shahid A Malik
- Department of Solid State and Structural Chemistry Unit, NMR Research Centre, Indian Institute of Science Bangalore-560012 India
| | - Somnath Mondal
- Department of Solid State and Structural Chemistry Unit, NMR Research Centre, Indian Institute of Science Bangalore-560012 India
| | - Hanudatta S Atreya
- Department of Solid State and Structural Chemistry Unit, NMR Research Centre, Indian Institute of Science Bangalore-560012 India
| |
Collapse
|
10
|
Lei R, Lee JP, Francis MB, Kumar S. Structural Regulation of a Neurofilament-Inspired Intrinsically Disordered Protein Brush by Multisite Phosphorylation. Biochemistry 2018; 57:4019-4028. [PMID: 29557644 DOI: 10.1021/acs.biochem.8b00007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Intrinsically disordered proteins (IDPs) play central roles in numerous cellular processes. While IDP structure and function are often regulated by multisite phosphorylation, the biophysical mechanisms linking these post-translational modifications to IDP structure remain elusive. For example, the intrinsically disordered C-terminal sidearm domain of the neurofilament heavy subunit (NFH-SA) forms a dense brush along axonal NF backbones and is subject to extensive serine phosphorylation. Yet, biophysical insight into the relationship between phosphorylation and structure has been limited by the lack of paradigms in which NF brush conformational responses can be measured in the setting of controlled phosphorylation. Here, we approach this question by immobilizing a recombinant NFH-SA (rNFH-SA) as IDP brushes onto glass, and controllably phosphorylating the sequence in situ with mitogen-activated protein kinase 1 (ERK2) preactivated by mitogen-activated protein kinase kinase (MKK). We then monitor brush height changes using atomic force microscopy, which shows that phosphorylation induces significant brush swelling to an extent that strongly depends upon pH and ionic strength, consistent with a mechanism in which phosphorylation regulates brush structure through local electrostatic interactions. Further consistent with this mechanism, the phosphorylated rNFH-SA brush may be dramatically condensed with micromolar concentrations of divalent cations. Phosphorylation-induced height changes are qualitatively reversible via alkaline phosphatase-mediated dephosphorylation. Our study demonstrates that multisite phosphorylation controls NFH-SA structure through modulation of chain electrostatics and points to a general strategy for engineering IDP-based interfaces that can be reversibly and dynamically modulated by enzymes.
Collapse
Affiliation(s)
| | | | - Matthew B Francis
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | | |
Collapse
|
11
|
Kwon NK, Lee TK, Kwak SK, Kim SY. Aggregation-Driven Controllable Plasmonic Transition of Silica-Coated Gold Nanoparticles with Temperature-Dependent Polymer-Nanoparticle Interactions for Potential Applications in Optoelectronic Devices. ACS APPLIED MATERIALS & INTERFACES 2017; 9:39688-39698. [PMID: 29053247 DOI: 10.1021/acsami.7b13123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Localized surface plasmon resonance (LSPR) effect relies on the shape, size, and dispersion state of metal nanoparticles and can potentially be employed in many applications such as chemical/biological sensor, optoelectronics, and photocatalyst. While complicated synthetic approaches changing shape and size of nanoparticles can control the intrinsic LSPR effect, here we show that controlling interparticle interactions with silica-coated gold nanoparticles (Au@SiO2 NPs) is a powerful approach, permitting wide range of optical bandwidth of gold nanoparticles with great stability. The interparticle interactions of Au@SiO2 NPs are controlled through concentration-, temperature-, and time-dependent polymer-induced interactions. The polymer-induced interactions modulate the state of particle dispersion, resulting an effective plasmonic shift by more than 200 nm. We further explore the microstructure of particle aggregation and explain mechanisms of plasmonic shift based on the results of small-angle X-ray scattering (SAXS) and discrete dipole approximation (DDA) calculation. We show that an effective control of LSPR behavior is now available through trapped aggregation of Au@SiO2 NPs with temperature variation. We anticipate that the suggested strategy can be employed in many practical applications such as optical bioimaging and optoelectronic devices.
Collapse
Affiliation(s)
- Na Kyung Kwon
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, Republic of Korea
| | - Tae Kyung Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, Republic of Korea
| | - Sang Kyu Kwak
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, Republic of Korea
| | - So Youn Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, Republic of Korea
| |
Collapse
|
12
|
Xie M, Hansen AL, Yuan J, Brüschweiler R. Residue-Specific Interactions of an Intrinsically Disordered Protein with Silica Nanoparticles and their Quantitative Prediction. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2016; 120:24463-24468. [PMID: 28337243 PMCID: PMC5358802 DOI: 10.1021/acs.jpcc.6b08213] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Elucidation of the driving forces that govern interactions between nanoparticles and intrinsically disordered proteins (IDP) is important for the understanding of the effect of nanoparticles in living systems and for the design of new nanoparticle-based assays to monitor health and combat disease. The quantitative interaction profile of the intrinsically disordered transactivation domain of p53 and its mutants with anionic silica nanoparticles is reported at atomic resolution using nuclear magnetic spin relaxation experiments. These profiles are analyzed with a novel interaction model that is based on a quantitative nanoparticle affinity scale separately derived for the 20 natural amino acids. The results demonstrate how the interplay of attractive and repulsive Coulomb interactions with hydrophobic effects is responsible for the sequence-dependent binding of a disordered protein to nanoparticles.
Collapse
Affiliation(s)
- Mouzhe Xie
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Alexandar L. Hansen
- Campus Chemical Instrument Center, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jiaqi Yuan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Rafael Brüschweiler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
- Campus Chemical Instrument Center, The Ohio State University, Columbus, Ohio 43210, United States
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio 43210, United States
- To whom correspondence should be addressed: Rafael Brüschweiler, Ph.D., Department of Chemistry and Biochemistry, CBEC building, The Ohio State University, Columbus, Ohio 43210, , Tel. 614-688-2083
| |
Collapse
|
13
|
Order and disorder in intermediate filament proteins. FEBS Lett 2015; 589:2464-76. [PMID: 26231765 DOI: 10.1016/j.febslet.2015.07.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 11/20/2022]
Abstract
Intermediate filaments (IFs), important components of the cytoskeleton, provide a versatile, tunable network of self-assembled proteins. IF proteins contain three distinct domains: an α-helical structured rod domain, flanked by intrinsically disordered head and tail domains. Recent studies demonstrated the functional importance of the disordered domains, which differ in length and amino-acid sequence among the 70 different human IF genes. Here, we investigate the biophysical properties of the disordered domains, and review recent findings on the interactions between them. Our analysis highlights key components governing IF functional roles in the cytoskeleton, where the intrinsically disordered domains dictate protein-protein interactions, supramolecular assembly, and macro-scale order.
Collapse
|