1
|
Yang S, Lee KH. Spontaneous Hollow Coacervate Transition of Silk Fibroin via Dilution and Its Transition to Microcapsules. Biomacromolecules 2025; 26:2513-2528. [PMID: 40063534 PMCID: PMC12004510 DOI: 10.1021/acs.biomac.5c00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2025] [Revised: 03/05/2025] [Accepted: 03/05/2025] [Indexed: 04/15/2025]
Abstract
Polymeric microcapsules are useful for drug delivery, microreactors, and cargo transport, but traditional fabrication methods require complex processes and harsh conditions. Coacervates, formed by liquid-liquid phase separation (LLPS), offer a promising alternative for microcapsule fabrication. Recent studies have shown that coacervates can spontaneously form hollow cavities under specific conditions. Here, we investigate the spontaneous hollow coacervate transition of silk fibroin (SF). SF coacervates, induced by mixing SF with dextran, calcium ions, and copper ions, transition to hollow coacervates upon dilution. Adding ethylenediaminetetraacetic acid (EDTA) further transforms them into vesicle-like capsule coacervates, which solidify into microcapsules. As a proof-of-concept, we successfully loaded a high-molecular-weight polymer cargo into the hollow cavity and bioactive enzyme cargo into the capsule layer by simply mixing the cargo with the coacervate solution. Our results demonstrate a facile, organic-solvent-free approach for fabricating SF-based microcapsules and provide insight into the mechanisms driving hollow coacervate formation.
Collapse
Affiliation(s)
- Sejun Yang
- Department
of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ki Hoon Lee
- Department
of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Research
Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| |
Collapse
|
2
|
Tran HA, Maraldo A, Ho TT, Thai MT, van Hilst Q, Joukhdar H, Kordanovski M, Sahoo JK, Hartsuk O, Santos M, Wise SG, Kaplan DL, Do TN, Kilian KA, Lim KS, Rnjak‐Kovacina J. Probing the Interplay of Protein Self-Assembly and Covalent Bond Formation in Photo-Crosslinked Silk Fibroin Hydrogels. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2025; 21:e2407923. [PMID: 39548941 PMCID: PMC12019910 DOI: 10.1002/smll.202407923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2024] [Revised: 10/27/2024] [Indexed: 11/18/2024]
Abstract
Covalent crosslinking of silk fibroin via native tyrosine residues has been extensively explored; however, while these materials are very promising for biomedical, optical, soft robotics, and sensor applications, their structure and mechanical properties are unstable over time. This instability results in spontaneous silk self-assembly and stiffening over time, a process that is poorly understood. This study investigates the interplay between self-assembly and di-tyrosine bond formation in silk hydrogels photo-crosslinked using ruthenium (Ru) and sodium persulfate (SPS) with visible light. The effects of silk concentration, molecular weight, Ru/SPS concentration, and solvent conditions are examined. The Ru/SPS system enables rapid crosslinking, achieving gelation within seconds and incorporating over 90% of silk into the network, even at very low protein concentrations (≥0.75% wt/v). A model emerges where silk self-assembly both before and after crosslinking affects protein phase separation, mesoscale structure, and dynamic changes in the hydrogel network over time. Silk concentration has the greatest impact on hydrogel properties, with higher silk concentration hydrogels experiencing two orders of magnitude increase in stiffness within 1 week. This new understanding and ability to tune hydrogel properties and dynamic stiffening aids in developing advanced materials for 4D biofabrication, sensing, 3D cancer models, drug delivery, and soft robotics.
Collapse
Affiliation(s)
- Hien A. Tran
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
| | - Anton Maraldo
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
| | - Trinh Thi‐Phuong Ho
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
| | - Mai Thanh Thai
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
- College of Engineering & Computer Science and VinUni‐Illinois Smart Health CenterHanoi100000Vietnam
| | - Quinn van Hilst
- Chronic Diseases ThemeSchool of Medical SciencesUniversity of SydneySydneyNSW2006Australia
| | - Habib Joukhdar
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
- Chronic Diseases ThemeSchool of Medical SciencesUniversity of SydneySydneyNSW2006Australia
| | - Marija Kordanovski
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
| | | | - Onur Hartsuk
- Department of Biomedical EngineeringTufts UniversityBostonMA02155USA
| | - Miguel Santos
- Chronic Diseases ThemeSchool of Medical SciencesUniversity of SydneySydneyNSW2006Australia
| | - Steven G. Wise
- Chronic Diseases ThemeSchool of Medical SciencesUniversity of SydneySydneyNSW2006Australia
| | - David L. Kaplan
- Department of Biomedical EngineeringTufts UniversityBostonMA02155USA
| | - Thanh Nho Do
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
| | - Kristopher A. Kilian
- School of ChemistryUniversity of New South WalesSydneyNSW2052Australia
- Australian Center for NanomedicineUniversity of New South WalesSydneyNSW2052Australia
- School of Materials Science and EngineeringUniversity of New South Wales SydneySydneyNSW2052Australia
- School of Clinical MedicineFaculty of Medicine and HealthUniversity of New South WalesSydneyNSW2052Australia
| | - Khoon S. Lim
- Chronic Diseases ThemeSchool of Medical SciencesUniversity of SydneySydneyNSW2006Australia
| | - Jelena Rnjak‐Kovacina
- Graduate School of Biomedical EngineeringUniversity of New South WalesSydneyNSW2052Australia
- Australian Center for NanomedicineUniversity of New South WalesSydneyNSW2052Australia
- Tyree Foundation Institute of Health EngineeringSydneyNSW2052Australia
| |
Collapse
|
3
|
Wigham C, Varude V, O'Donnell H, Zha RH. The role of phosphate in silk fibroin self-assembly: a Hofmeister study. SOFT MATTER 2025; 21:2461-2470. [PMID: 40035478 DOI: 10.1039/d4sm01198h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2025]
Abstract
Silk fibroin is the primary protein component of the threads of Bombyx mori silkworm cocoons. Previous work has demonstrated that silk fibroin can self-assemble at solid-liquid interfaces to form dense, nanothin coatings that grow continuously from a substrate surface when exposed to potassium phosphate, a kosmotropic salt. Herein, the role of potassium phosphate in promoting silk fibroin self-assembly in solution and on surfaces is studied and compared to other salts in the Hofmeister series. Results show that strong kosmotropes, such as ammonium sulfate and potassium phosphate, promote a bimodal distribution of assembled species in solution that is indicative of a nucleation-growth mechanism. Interestingly, silk fibroin assemblies formed by potassium phosphate contain the highest β-sheet content, suggesting that phosphate-specific interactions play a role in silk fibroin self-assembly. In the presence of kosmotropic salts, silk fibroin nanoaggregates continuously accumulate at solid-liquid interfaces with varying early- and late-stage adsorption rates. Interfacial coatings formed in the presence of potassium phosphate are smooth, dense, and completely cover the underlying substrate without evidence of large-scale aggregation, whereas other kosmotropes generate rough, heterogeneous coatings. These studies thus decouple the kosmotropic effects of phosphate (via disruption of the protein hydration shell) from ion-specific behavior in driving silk fibroin self-assembly.
Collapse
Affiliation(s)
- Caleb Wigham
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Vrushali Varude
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Henry O'Donnell
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - R Helen Zha
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| |
Collapse
|
4
|
Numata K. The Biology of Natural Polymers Accelerates and Expands the Science of Biomacromolecules: A Focus on Structural Proteins. Biomacromolecules 2025; 26:1393-1403. [PMID: 39965779 PMCID: PMC11898061 DOI: 10.1021/acs.biomac.4c01621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2024] [Revised: 01/09/2025] [Accepted: 01/10/2025] [Indexed: 02/20/2025]
Abstract
This Perspective explores the use of biomacromolecules in natural materials synthesized by living organisms, such as spider silk, in the development of sustainable synthetic materials. Currently employed synthetic polymers lack the hierarchical complexity and unique properties of natural materials composed of biomacromolecules. By understanding the composition of these natural materials, it may be able to reproduce their properties synthetically. Additionally, research directions involving the use of renewable resources such as nitrogen and carbon dioxide from the air and seawater to develop biomacromolecules such as spider silk and biopolyester via photosynthetic organisms are reviewed. Next-generation biomacromolecule research will aid in the creation of a sustainable global society, advancing fields such as biomanufacturing, agriculture, aquaculture, and other industries.
Collapse
Affiliation(s)
- Keiji Numata
- Department
of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- Biomacromolecules
Research Team, RIKEN Center for Sustainable
Resource Science, 2-1
Hirosawa, Wako, Saitama 351-0198, Japan
- Institute
for Advanced Biosciences, Keio University, Nipponkoku 403-1, Daihouji, Tsuruoka, Yamagata 997-0017, Japan
| |
Collapse
|
5
|
Yang S, Yu Y, Jo S, Lee Y, Son S, Lee KH. Calcium ion-triggered liquid-liquid phase separation of silk fibroin and spinning through acidification and shear stress. Nat Commun 2024; 15:10394. [PMID: 39614109 PMCID: PMC11607318 DOI: 10.1038/s41467-024-54588-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 11/15/2024] [Indexed: 12/01/2024] Open
Abstract
Many studies try to comprehend and replicate the natural silk spinning process due to its energy-efficient and eco-friendly process. In contrast to spider silk, the mechanisms of how silkworm silk fibroin (SF) undergoes liquid-liquid phase separation (LLPS) concerning the various environmental factors in the silk glands or how the SF coacervates transform into fibers remain unexplored. Here, we show that calcium ions, among the most abundant metal ions inside the silk glands, induce LLPS of SF under macromolecular crowded conditions by increasing both hydrophobic and electrostatic interactions between SF. Furthermore, SF coacervates assemble and further develop into fibrils under acidification and shear force. Finally, we prepare SF fiber using a pultrusion-based dry spinning, mirroring the natural silk spinning system. Unlike previous artificial spinning methods requiring concentrated solutions or harsh solvents, our process uses a less concentrated aqueous SF solution and minimal shear force, offering a biomimetic approach to fiber production.
Collapse
Affiliation(s)
- Sejun Yang
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Yeonwoo Yu
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seonghyeon Jo
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Yehee Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Seojin Son
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
- Samsung SDI, 150-20, Gongse-ro, Giheung-gu, Yongin, Gyeonggi-do, 17084, Republic of Korea
| | - Ki Hoon Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
- Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
| |
Collapse
|
6
|
Landreh M, Osterholz H, Chen G, Knight SD, Rising A, Leppert A. Liquid-liquid crystalline phase separation of spider silk proteins. Commun Chem 2024; 7:260. [PMID: 39533043 PMCID: PMC11557605 DOI: 10.1038/s42004-024-01357-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 10/28/2024] [Indexed: 11/16/2024] Open
Abstract
Liquid-liquid phase separation (LLPS) of proteins can be considered an intermediate solubility regime between disperse solutions and solid fibers. While LLPS has been described for several pathogenic amyloids, recent evidence suggests that it is similarly relevant for functional amyloids. Here, we review the evidence that links spider silk proteins (spidroins) and LLPS and its role in the spinning process. Major ampullate spidroins undergo LLPS mediated by stickers and spacers in their repeat regions. During spinning, the spidroins droplets shift from liquid to crystalline states. Shear force, altered ion composition, and pH changes cause micelle-like spidroin assemblies to form an increasingly ordered liquid-crystalline phase. Interactions between polyalanine regions in the repeat regions ultimately yield the characteristic β-crystalline structure of mature dragline silk fibers. Based on these findings, we hypothesize that liquid-liquid crystalline phase separation (LLCPS) can describe the molecular and macroscopic features of the phase transitions of major ampullate spidroins during spinning and speculate whether other silk types may use a similar mechanism to convert from liquid dope to solid fiber.
Collapse
Affiliation(s)
- Michael Landreh
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden.
| | - Hannah Osterholz
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Gefei Chen
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
- Department of Medicine Huddinge, Karolinska Institutet, Huddinge, Sweden
| | - Stefan D Knight
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Anna Rising
- Department of Medicine Huddinge, Karolinska Institutet, Huddinge, Sweden.
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Axel Leppert
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden.
| |
Collapse
|
7
|
Wigham C, Fink TD, Sorci M, O'Reilly P, Park S, Kim J, Varude VR, Zha RH. Phosphate-Driven Interfacial Self-Assembly of Silk Fibroin for Continuous Noncovalent Growth of Nanothin Defect-Free Coatings. ACS APPLIED MATERIALS & INTERFACES 2024; 16:58121-58134. [PMID: 39413432 DOI: 10.1021/acsami.4c07528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2024]
Abstract
Silk fibroin is a fiber-forming protein derived from the thread of Bombyx mori silkworm cocoons. This biocompatible protein, under the kosmotropic influence of potassium phosphate, can undergo supramolecular self-assembly driven by a random coil to β-sheet secondary structure transition. By leveraging concurrent nonspecific adsorption and self-assembly of silk fibroin, we demonstrate an interfacial phenomenon that yields adherent, defect-free nanothin protein coatings that grow continuously in time, without observable saturation in mass deposition. This noncovalent growth of silk fibroin coatings is a departure from traditionally studied protein adsorption phenomena, which generally yield adsorbed layers that saturate in mass with time and often do not completely cover the surface. Here, we explore the fundamental mechanisms of coating growth by examining the effects of coating solution parameters that promote or inhibit silk fibroin self-assembly. Results show a strong dependence of coating kinetics and structure on solution pH, salt species, and salt concentration. Moreover, coating growth was observed to occur in two stages: an early stage driven by protein-surface interactions and a late stage driven by protein-protein interactions. To describe this phenomenon, we developed a kinetic adsorption model with Langmuir-like behavior at early times and a constant steady-state growth rate at later times. Structural analysis by FTIR and photoinduced force microscopy show that small β-sheet-rich structures serve as anchoring sites for absorbing protein nanoaggregates, which is critical for coating formation. Additionally, β-sheets are preferentially located at the interface between protein nanoaggregates in the coating, suggesting their role in forming stable, robust coatings.
Collapse
Affiliation(s)
- Caleb Wigham
- Department of Chemical and Biological Engineering, 110 Eighth Street, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Tanner D Fink
- Department of Chemical and Biological Engineering, 110 Eighth Street, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Mirco Sorci
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | | | - Sung Park
- Molecular Vista, San Jose, California 95119, United States
| | - Jeongae Kim
- Department of Chemical and Biological Engineering, 110 Eighth Street, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Vrushali R Varude
- Department of Chemical and Biological Engineering, 110 Eighth Street, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - R Helen Zha
- Department of Chemical and Biological Engineering, 110 Eighth Street, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| |
Collapse
|
8
|
Numata K, Kaplan DL. Silk Proteins: Designs from Nature with Multipurpose Utility and Infinite Future Possibilities. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2411256. [PMID: 39468893 DOI: 10.1002/adma.202411256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 09/18/2024] [Indexed: 10/30/2024]
Abstract
This is a Perspective on nature as a story-teller, where inputs of evolution drove the remarkable protein designs found in silks. This selection process has resulted in silk materials with novel chemistry and properties to support organism survival in nature, yet with newfound utility in everything from comic books and automobiles to medicine. With growing global concerns related to environmental health, silks also serve as an invaluable instructional guide to the future of sustainable material designs.
Collapse
Affiliation(s)
- Keiji Numata
- Department of Material Chemistry, Kyoto University, Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto, 6158510, Japan
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Colby, Medford, MA, 2155, USA
| |
Collapse
|
9
|
Yin Y, Griffo A, Gutiérrez Cruz A, Hähl H, Jacobs K, Linder MB. Effect of Phosphate on the Molecular Properties, Interactions, and Assembly of Engineered Spider Silk Proteins. Biomacromolecules 2024; 25:3990-4000. [PMID: 38916967 PMCID: PMC11238326 DOI: 10.1021/acs.biomac.4c00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 06/04/2024] [Accepted: 06/04/2024] [Indexed: 06/27/2024]
Abstract
Phosphate plays a vital role in spider silk spinning and has been utilized in numerous artificial silk spinning attempts to replicate the remarkable mechanical properties of natural silk fiber. Its application in artificial processes has, however, yielded varying outcomes. It is thus necessary to investigate the origins and mechanisms behind these differences. By using recombinant silk protein SC-ADF3 derived from the garden spider Araneus diadematus, here, we describe its conformational changes under various conditions, elucidating the effect of phosphate on SC-ADF3 silk protein properties and interactions. Our results demonstrate that elevated phosphate levels induce the irreversible conformational conversion of SC-ADF3 from random coils to β-sheet structures, leading to decreased protein solubility over time. Furthermore, exposure of SC-ADF3 to phosphate stiffens already formed structures and reduces the ability to form new interactions. Our findings offer insights into the underlying mechanism through which phosphate-induced β-sheet structures in ADF3-related silk proteins impede fiber formation in the subsequent phases. From a broader perspective, our studies emphasize the significance of silk protein conformation for functional material formation, highlighting that the formation of β-sheet structures at the initial stages of protein assembly will affect the outcome of material forming processes.
Collapse
Affiliation(s)
- Yin Yin
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
- Finnish
Centre of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Kemistintie 1, 02150 Espoo, Finland
| | - Alessandra Griffo
- Biophysical
Engineering Group, Max Planck Institute
for Medical Research, 69120 Heidelberg, Germany
- Department
of Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany
| | - Adrián Gutiérrez Cruz
- Department
of Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany
| | - Hendrik Hähl
- Department
of Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany
| | - Karin Jacobs
- Department
of Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany
- Max
Planck School “Matter to Life”, Jahnstraße 29, 69120 Heidelberg, Germany
| | - Markus B. Linder
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland
- Finnish
Centre of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Kemistintie 1, 02150 Espoo, Finland
| |
Collapse
|
10
|
Wu S, Liu Z, Gong C, Li W, Xu S, Wen R, Feng W, Qiu Z, Yan Y. Spider-silk-inspired strong and tough hydrogel fibers with anti-freezing and water retention properties. Nat Commun 2024; 15:4441. [PMID: 38789409 PMCID: PMC11126733 DOI: 10.1038/s41467-024-48745-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Ideal hydrogel fibers with high toughness and environmental tolerance are indispensable for their long-term application in flexible electronics as actuating and sensing elements. However, current hydrogel fibers exhibit poor mechanical properties and environmental instability due to their intrinsically weak molecular (chain) interactions. Inspired by the multilevel adjustment of spider silk network structure by ions, bionic hydrogel fibers with elaborated ionic crosslinking and crystalline domains are constructed. Bionic hydrogel fibers show a toughness of 162.25 ± 21.99 megajoules per cubic meter, comparable to that of spider silks. The demonstrated bionic structural engineering strategy can be generalized to other polymers and inorganic salts for fabricating hydrogel fibers with broadly tunable mechanical properties. In addition, the introduction of inorganic salt/glycerol/water ternary solvent during constructing bionic structures endows hydrogel fibers with anti-freezing, water retention, and self-regeneration properties. This work provides ideas to fabricate hydrogel fibers with high mechanical properties and stability for flexible electronics.
Collapse
Affiliation(s)
- Shaoji Wu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Zhao Liu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Caihong Gong
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Wanjiang Li
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Sijia Xu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Rui Wen
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Wen Feng
- Guangdong Medical Products Administration Key Laboratory for Quality Research and Evaluation of Medical Textile Products, Guangzhou, 511447, PR China.
| | - Zhiming Qiu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China
| | - Yurong Yan
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, PR China.
- Key Lab of Guangdong High Property & Functional Polymer Materials, Guangzhou, 510640, PR China.
| |
Collapse
|
11
|
Hovanová V, Hovan A, Humenik M, Sedlák E. Only kosmotrope anions trigger fibrillization of the recombinant core spidroin eADF4(C16) from Araneus diadematus. Protein Sci 2023; 32:e4832. [PMID: 37937854 PMCID: PMC10661072 DOI: 10.1002/pro.4832] [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: 07/18/2023] [Revised: 10/20/2023] [Accepted: 11/05/2023] [Indexed: 11/09/2023]
Abstract
Recombinant core spidroin eADF4(C16) has received increasing attention due to its ability to form micro- and nano-structured scaffolds, which are based on nanofibrils with great potential for biomedical and biotechnological applications. Phosphate anions have been demonstrated to trigger the eADF4(C16) self-assembly into cross-beta fibrils. In the present work, we systematically addressed the effect of nine sodium anions, namely SO4 2- , HPO4 2- (Pi), F- , Cl- , Br- , NO3 - , I- , SCN- , and ClO4 - from the Hofmeister series on the in vitro self-assembly kinetics of eADF4(C16). We show that besides the phosphate anions, only kosmotropic anions such as sulfate and fluoride can initiate the eADF4(C16) fibril formation. Global analysis of the self-assembly kinetics, utilizing the platform AmyloFit, showed the nucleation-based mechanism with a major role of secondary nucleation, surprisingly independent of the type of the kosmotropic anion. The rate constant of the fibril elongation in mixtures of phosphate anions with other studied anions correlated with their kosmotropic or chaotropic position in the Hofmeister series. Our findings suggest an important role of anion hydration in the eADF4(C16) fibrillization process.
Collapse
Affiliation(s)
- Veronika Hovanová
- Center for Interdisciplinary Biosciences, Technology and Innovation ParkP.J. Šafárik UniversityKošiceSlovakia
- Department of Biophysics, Faculty of ScienceP.J. Šafárik UniversityKošiceSlovakia
| | - Andrej Hovan
- Department of Biophysics, Faculty of ScienceP.J. Šafárik UniversityKošiceSlovakia
| | - Martin Humenik
- Department of Biomaterials, Faculty of Engineering ScienceUniversity BayreuthBayreuthGermany
| | - Erik Sedlák
- Center for Interdisciplinary Biosciences, Technology and Innovation ParkP.J. Šafárik UniversityKošiceSlovakia
- Department of Biochemistry, Faculty of ScienceP.J. Šafárik UniversityKošiceSlovakia
| |
Collapse
|
12
|
Feng J, Gabryelczyk B, Tunn I, Osmekhina E, Linder MB. A Minispidroin Guides the Molecular Design for Cellular Condensation Mechanisms in S. cerevisiae. ACS Synth Biol 2023; 12:3050-3063. [PMID: 37688556 PMCID: PMC10594646 DOI: 10.1021/acssynbio.3c00374] [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: 06/18/2023] [Indexed: 09/11/2023]
Abstract
Structural engineering of molecules for condensation is an emerging technique within synthetic biology. Liquid-liquid phase separation of biomolecules leading to condensation is a central step in the assembly of biological materials into their functional forms. Intracellular condensates can also function within cells in a regulatory manner to facilitate reaction pathways and to compartmentalize interactions. We need to develop a strong understanding of how to design molecules for condensates and how their in vivo-in vitro properties are related. The spider silk protein NT2RepCT undergoes condensation during its fiber-forming process. Using parallel in vivo and in vitro characterization, in this study, we mapped the effects of intracellular conditions for NT2RepCT and its several structural variants. We found that intracellular conditions may suppress to some extent condensation whereas molecular crowding affects both condensate properties and their formation. Intracellular characterization of protein condensation allowed experiments on pH effects and solubilization to be performed within yeast cells. The growth of intracellular NT2RepCT condensates was restricted, and Ostwald ripening was not observed in yeast cells, in contrast to earlier observations in E. coli. Our results lead the way to using intracellular condensation to screen for properties of molecular assembly. For characterizing different structural variants, intracellular functional characterization can eliminate the need for time-consuming batch purification and in vitro condensation. Therefore, we suggest that the in vivo-in vitro understanding will become useful in, e.g., high-throughput screening for molecular functions and in strategies for designing tunable intracellular condensates.
Collapse
Affiliation(s)
- Jianhui Feng
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Bartosz Gabryelczyk
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Isabell Tunn
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Ekaterina Osmekhina
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| | - Markus B. Linder
- Department of Bioproducts
and Biosystems, School of Chemical Engineering and Academy of Finland
Center of Excellence in Life-Inspired Hybrid Materials (LIBER), Aalto University, Espoo 02150, Finland
| |
Collapse
|
13
|
Trossmann VT, Lentz S, Scheibel T. Factors Influencing Properties of Spider Silk Coatings and Their Interactions within a Biological Environment. J Funct Biomater 2023; 14:434. [PMID: 37623678 PMCID: PMC10455157 DOI: 10.3390/jfb14080434] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/10/2023] [Accepted: 08/16/2023] [Indexed: 08/26/2023] Open
Abstract
Biomaterials are an indispensable part of biomedical research. However, although many materials display suitable application-specific properties, they provide only poor biocompatibility when implanted into a human/animal body leading to inflammation and rejection reactions. Coatings made of spider silk proteins are promising alternatives for various applications since they are biocompatible, non-toxic and anti-inflammatory. Nevertheless, the biological response toward a spider silk coating cannot be generalized. The properties of spider silk coatings are influenced by many factors, including silk source, solvent, the substrate to be coated, pre- and post-treatments and the processing technique. All these factors consequently affect the biological response of the environment and the putative application of the appropriate silk coating. Here, we summarize recently identified factors to be considered before spider silk processing as well as physicochemical characterization methods. Furthermore, we highlight important results of biological evaluations to emphasize the importance of adjustability and adaption to a specific application. Finally, we provide an experimental matrix of parameters to be considered for a specific application and a guided biological response as exemplarily tested with two different fibroblast cell lines.
Collapse
Affiliation(s)
- Vanessa T. Trossmann
- Chair of Biomaterials, Faculty of Engineering Science, University of Bayreuth, Prof.-Rüdiger-Bormann-Straße 1, 95447 Bayreuth, Germany; (V.T.T.); (S.L.)
| | - Sarah Lentz
- Chair of Biomaterials, Faculty of Engineering Science, University of Bayreuth, Prof.-Rüdiger-Bormann-Straße 1, 95447 Bayreuth, Germany; (V.T.T.); (S.L.)
| | - Thomas Scheibel
- Chair of Biomaterials, Faculty of Engineering Science, University of Bayreuth, Prof.-Rüdiger-Bormann-Straße 1, 95447 Bayreuth, Germany; (V.T.T.); (S.L.)
- Bayreuth Center for Colloids and Interfaces (BZKG), University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
- Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
- Bayreuth Center for Molecular Biosciences (BZMB), University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
- Bayreuth Materials Center (BayMAT), University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
- Faculty of Medicine, University of Würzburg, Pleicherwall 2, 97070 Würzburg, Germany
| |
Collapse
|
14
|
Leppert A, Chen G, Lama D, Sahin C, Railaite V, Shilkova O, Arndt T, Marklund EG, Lane DP, Rising A, Landreh M. Liquid-Liquid Phase Separation Primes Spider Silk Proteins for Fiber Formation via a Conditional Sticker Domain. NANO LETTERS 2023. [PMID: 37084706 DOI: 10.1021/acs.nanolett.3c00773] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Many protein condensates can convert to fibrillar aggregates, but the underlying mechanisms are unclear. Liquid-liquid phase separation (LLPS) of spider silk proteins, spidroins, suggests a regulatory switch between both states. Here, we combine microscopy and native mass spectrometry to investigate the influence of protein sequence, ions, and regulatory domains on spidroin LLPS. We find that salting out-effects drive LLPS via low-affinity stickers in the repeat domains. Interestingly, conditions that enable LLPS simultaneously cause dissociation of the dimeric C-terminal domain (CTD), priming it for aggregation. Since the CTD enhances LLPS of spidroins but is also required for their conversion into amyloid-like fibers, we expand the stickers and spacers-model of phase separation with the concept of folded domains as conditional stickers that represent regulatory units.
Collapse
Affiliation(s)
- Axel Leppert
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
| | - Gefei Chen
- Department of Biosciences and Nutrition, Karolinska Institutet, S-14157 Huddinge, Sweden
| | - Dilraj Lama
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
| | - Cagla Sahin
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
- Linderstro̷m-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Vaida Railaite
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
| | - Olga Shilkova
- Department of Biosciences and Nutrition, Karolinska Institutet, S-14157 Huddinge, Sweden
| | - Tina Arndt
- Department of Biosciences and Nutrition, Karolinska Institutet, S-14157 Huddinge, Sweden
| | - Erik G Marklund
- Department of Chemistry - BMC, Uppsala University, S-75123 Uppsala, Sweden
| | - David P Lane
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
| | - Anna Rising
- Department of Biosciences and Nutrition, Karolinska Institutet, S-14157 Huddinge, Sweden
- Department of Anatomy Physiology and Biochemistry, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, S-17165 Solna, Sweden
- Department of Cell and Molecular Biology, Uppsala University, S-75124 Uppsala, Sweden
| |
Collapse
|
15
|
Oktaviani NA, Malay AD, Matsugami A, Hayashi F, Numata K. Unusual p Ka Values Mediate the Self-Assembly of Spider Dragline Silk Proteins. Biomacromolecules 2023; 24:1604-1616. [PMID: 36990448 PMCID: PMC10091414 DOI: 10.1021/acs.biomac.2c01344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/17/2023] [Indexed: 03/31/2023]
Abstract
Spider dragline silk is a remarkably tough biomaterial and composed primarily of spidroins MaSp1 and MaSp2. During fiber self-assembly, the spidroin N-terminal domains (NTDs) undergo rapid dimerization in response to a pH gradient. However, obtaining a detailed understanding of this mechanism has been hampered by a lack of direct evidence regarding the protonation states of key ionic residues. Here, we elucidated the solution structures of MaSp1 and MaSp2 NTDs from Trichonephila clavipes and determined the experimental pKa values of conserved residues involved in dimerization using NMR. Surprisingly, we found that the Asp40 located on an acidic cluster protonates at an unusually high pH (∼6.5-7.1), suggesting the first step in the pH response. Then, protonation of Glu119 and Glu79 follows, with pKas above their intrinsic values, contributing toward stable dimer formation. We propose that exploiting the atypical pKa values is a strategy to achieve tight spatiotemporal control of spider silk self-assembly.
Collapse
Affiliation(s)
- Nur Alia Oktaviani
- Biomacromolecules
Research Team, RIKEN Center for the Sustainable
Resource Sciences, 2-1
Hirosawa, Wako, Saitama 351-0198, Japan
| | - Ali D. Malay
- Biomacromolecules
Research Team, RIKEN Center for the Sustainable
Resource Sciences, 2-1
Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akimasa Matsugami
- Advanced
NMR Application and Platform Team, NMR Research and Collaboration
Group, NMR Science and Development Division, RIKEN SPring-8 Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Fumiaki Hayashi
- Advanced
NMR Application and Platform Team, NMR Research and Collaboration
Group, NMR Science and Development Division, RIKEN SPring-8 Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Keiji Numata
- Biomacromolecules
Research Team, RIKEN Center for the Sustainable
Resource Sciences, 2-1
Hirosawa, Wako, Saitama 351-0198, Japan
- Department
of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyotodaigaku,
Katsura, Kyoto 615-8510, Japan
- Institute
for Advanced Bioscience, Keio University, 403-1 Nihonkoku, Daihouji, Tsuruoka, Yamagata 997-0017, Japan
| |
Collapse
|
16
|
Rising A, Harrington MJ. Biological Materials Processing: Time-Tested Tricks for Sustainable Fiber Fabrication. Chem Rev 2023; 123:2155-2199. [PMID: 36508546 DOI: 10.1021/acs.chemrev.2c00465] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
There is an urgent need to improve the sustainability of the materials we produce and use. Here, we explore what humans can learn from nature about how to sustainably fabricate polymeric fibers with excellent material properties by reviewing the physical and chemical aspects of materials processing distilled from diverse model systems, including spider silk, mussel byssus, velvet worm slime, hagfish slime, and mistletoe viscin. We identify common and divergent strategies, highlighting the potential for bioinspired design and technology transfer. Despite the diversity of the biopolymeric fibers surveyed, we identify several common strategies across multiple systems, including: (1) use of stimuli-responsive biomolecular building blocks, (2) use of concentrated fluid precursor phases (e.g., coacervates and liquid crystals) stored under controlled chemical conditions, and (3) use of chemical (pH, salt concentration, redox chemistry) and physical (mechanical shear, extensional flow) stimuli to trigger the transition from fluid precursor to solid material. Importantly, because these materials largely form and function outside of the body of the organisms, these principles can more easily be transferred for bioinspired design in synthetic systems. We end the review by discussing ongoing efforts and challenges to mimic biological model systems, with a particular focus on artificial spider silks and mussel-inspired materials.
Collapse
Affiliation(s)
- Anna Rising
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge 141 52, Sweden.,Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala 750 07, Sweden
| | | |
Collapse
|
17
|
Otis JB, Sharpe S. Sequence Context and Complex Hofmeister Salt Interactions Dictate Phase Separation Propensity of Resilin-like Polypeptides. Biomacromolecules 2022; 23:5225-5238. [PMID: 36378745 DOI: 10.1021/acs.biomac.2c01027] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Resilin is an elastic material found in insects with exceptional durability, resilience, and extensibility, making it a promising biomaterial for tissue engineering. The monomeric precursor, pro-resilin, undergoes thermo-responsive self-assembly through liquid-liquid phase separation (LLPS). Understanding the molecular details of this assembly process is critical to developing complex biomaterials. The present study investigates the interplay between the solvent, sequence syntax, structure, and dynamics in promoting LLPS of resilin-like-polypeptides (RLPs) derived from domains 1 and 3 of Drosophila melanogaster pro-resilin. NMR, UV-vis, and microscopy data demonstrate that while kosmotropic salts and low pH promote LLPS, the effects of chaotropic salts with increasing pH are more complex. Subtle variations between the repeating amino acid motifs of resilin domain 1 and domain 3 lead to significantly different salt and pH dependence of LLPS, with domain 3 sequence motifs more strongly favoring phase separation under most conditions. These findings provide new insight into the molecular drivers of RLP phase separation and the complex roles of both RLP sequence and solution composition in fine-tuning assembly conditions.
Collapse
Affiliation(s)
- James Brandt Otis
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ONM5G 0A4, Canada.,Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ONM5S 1A8, Canada
| | - Simon Sharpe
- Molecular Medicine, Hospital for Sick Children, 686 Bay St, Toronto, ONM5G 0A4, Canada.,Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ONM5S 1A8, Canada
| |
Collapse
|
18
|
Abstract
![]()
The tiny spider makes
dragline silk fibers with unbeatable toughness,
all under the most innocuous conditions. Scientists have persistently
tried to emulate its natural silk spinning process using recombinant
proteins with a view toward creating a new wave of smart materials,
yet most efforts have fallen short of attaining the native fiber’s
excellent mechanical properties. One reason for these shortcomings
may be that artificial spider silk systems tend to be overly simplified
and may not sufficiently take into account the true complexity of
the underlying protein sequences and of the multidimensional aspects
of the natural self-assembly process that give rise to the hierarchically
structured fibers. Here, we discuss recent findings regarding the
material constituents of spider dragline silk, including novel spidroin
subtypes, nonspidroin proteins, and possible involvement of post-translational
modifications, which together suggest a complexity that transcends
the two-component MaSp1/MaSp2 system. We subsequently consider insights
into the spidroin domain functions, structures, and overall mechanisms
for the rapid transition from disordered soluble protein into a highly
organized fiber, including the possibility of viewing spider silk
self-assembly through a framework relevant to biomolecular condensates.
Finally, we consider the concept of “biomimetics” as
it applies to artificial spider silk production with a focus on key
practical aspects of design and evaluation that may hopefully inform
efforts to more closely reproduce the remarkable structure and function
of the native silk fiber using artificial methods.
Collapse
Affiliation(s)
- Ali D Malay
- Biomacromolecules Research Team, Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hamish C Craig
- Biomacromolecules Research Team, Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Jianming Chen
- Biomacromolecules Research Team, Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Nur Alia Oktaviani
- Biomacromolecules Research Team, Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.,Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
19
|
Chen J, Tsuchiya K, Masunaga H, Malay AD, Numata K. A silk composite fiber reinforced by telechelic-type polyalanine and its strengthening mechanism. Polym Chem 2022. [DOI: 10.1039/d2py00030j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A telechelic-type polyalanine was doped in silkworm silk fibroins to prepare reinforced composite fibers, which exhibited 42% and 51% higher mechanical properties than silk-only fibers in terms of tensile strength and toughness, respectively.
Collapse
Affiliation(s)
- Jianming Chen
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kousuke Tsuchiya
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Hiroyasu Masunaga
- Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Ali D. Malay
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
20
|
Malay AD, Suzuki T, Katashima T, Kono N, Arakawa K, Numata K. Spider silk self-assembly via modular liquid-liquid phase separation and nanofibrillation. SCIENCE ADVANCES 2020; 6:6/45/eabb6030. [PMID: 33148640 PMCID: PMC7673682 DOI: 10.1126/sciadv.abb6030] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 09/16/2020] [Indexed: 05/17/2023]
Abstract
Spider silk fiber rapidly assembles from spidroin protein in soluble state via an incompletely understood mechanism. Here, we present an integrated model for silk formation that incorporates the effects of multiple chemical and physical gradients on the different spidroin functional domains. Central to the process is liquid-liquid phase separation (LLPS) that occurs in response to multivalent anions such as phosphate, mediated by the carboxyl-terminal and repetitive domains. Acidification coupled with LLPS triggers the swift self-assembly of nanofibril networks, facilitated by dimerization of the amino-terminal domain, and leads to a liquid-to-solid phase transition. Mechanical stress applied to the fibril structures yields macroscopic fibers with hierarchical organization and enriched for β-sheet conformations. Studies using native silk gland material corroborate our findings on spidroin phase separation. Our results suggest an intriguing parallel between silk assembly and other LLPS-mediated mechanisms, such as found in intracellular membraneless organelles and protein aggregation disorders.
Collapse
Affiliation(s)
- Ali D Malay
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takuya Katashima
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Nobuaki Kono
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan
| | - Kazuharu Arakawa
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
- Department of Material Chemistry, Kyoto University, Katsura, Nishikyo, Kyoto 615-8510, Japan
| |
Collapse
|
21
|
Oktaviani NA, Malay AD, Matsugami A, Hayashi F, Numata K. Nearly complete 1H, 13C and 15N chemical shift assignment of monomeric form of N-terminal domain of Nephila clavipes major ampullate spidroin 2. BIOMOLECULAR NMR ASSIGNMENTS 2020; 14:335-338. [PMID: 32767002 DOI: 10.1007/s12104-020-09972-5] [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] [Received: 06/27/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Spider dragline silk is well recognized due to its excellent mechanical properties. Dragline silk protein mainly consists of two proteins, namely, major ampullate spidroin 1 (MaSp1) and major ampullate spidroin 2 (MaSp2). The MaSp N-terminal domain (NTD) conformation displays a strong dependence on ion and pH gradients, which is crucial for the self-assembly behavior of spider silk. In the spider major ampullate gland, where the pH is neutral and concentration of NaCl is high, the NTD forms a monomer. In contrast, within the spinning duct, where pH becomes more acidic (to pH ~ 5) and the concentration of salt is low, NTD forms a dimer in antiparallel orientation. In this study, we report near-complete backbone and side chain chemical shift assignment of the monomeric form of NTD of MaSp2 from Nephila clavipes at pH 7 in the presence of 300 mM NaCl. Our NMR data demonstrate that secondary structure of monomeric form of NTD MaSp2 consists of five helix regions.
Collapse
Affiliation(s)
- Nur Alia Oktaviani
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
| | - Ali D Malay
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Akimasa Matsugami
- Advanced NMR Application and Platform Team, NMR Research and Collaboration Group, NMR Science and Development Division, RIKEN SPring-8 Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Fumiaki Hayashi
- Advanced NMR Application and Platform Team, NMR Research and Collaboration Group, NMR Science and Development Division, RIKEN SPring-8 Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
| |
Collapse
|
22
|
Chen J, Ohta Y, Nakamura H, Masunaga H, Numata K. Aqueous spinning system with a citrate buffer for highly extensible silk fibers. Polym J 2020. [DOI: 10.1038/s41428-020-00419-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
23
|
Wu J, Guo W, Zhang L, Wang Y, Liu L, Wang W, Sun Y, Tao J, Wang X. One-step preparation and characterization of silk nano- and microspheres. Polym J 2020. [DOI: 10.1038/s41428-020-0392-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
24
|
Finnigan W, Roberts AD, Ligorio C, Scrutton NS, Breitling R, Blaker JJ, Takano E. The effect of terminal globular domains on the response of recombinant mini-spidroins to fiber spinning triggers. Sci Rep 2020; 10:10671. [PMID: 32606438 PMCID: PMC7327021 DOI: 10.1038/s41598-020-67703-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 06/11/2020] [Indexed: 12/31/2022] Open
Abstract
Spider silk spidroins consist of long repetitive protein strands, flanked by globular terminal domains. The globular domains are often omitted in recombinant spidroins, but are thought to be essential for the spiders' natural spinning process. Mimicking this spinning process could be an essential step towards producing strong synthetic spider silk. Here we describe the production of a range of mini-spidroins with both terminal domains, and characterize their response to a number of biomimetic spinning triggers. Our results suggest that mini-spidroins which are able to form protein micelles due to the addition of both terminal domains exhibit shear-thinning, a property which native spidroins also show. Furthermore, our data also suggest that a pH drop alone is insufficient to trigger assembly in a wet-spinning process, and must be combined with salting-out for effective fiber formation. With these insights, we applied these assembly triggers for relatively biomimetic wet spinning. This work adds to the foundation of literature for developing improved biomimetic spinning techniques, which ought to result in synthetic silk that more closely approximates the unique properties of native spider silk.
Collapse
Affiliation(s)
- William Finnigan
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Aled D Roberts
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Cosimo Ligorio
- Department of Materials, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Nigel S Scrutton
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Rainer Breitling
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Jonny J Blaker
- Bio-Active Materials Group, Department of Materials, The University of Manchester, Manchester, M13 9PL, UK
| | - Eriko Takano
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK.
| |
Collapse
|
25
|
Sogawa H, Nakano K, Tateishi A, Tajima K, Numata K. Surface Analysis of Native Spider Draglines by FE-SEM and XPS. Front Bioeng Biotechnol 2020; 8:231. [PMID: 32266250 PMCID: PMC7099578 DOI: 10.3389/fbioe.2020.00231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 03/05/2020] [Indexed: 11/13/2022] Open
Abstract
Although the physical and biological functions of the skin layer of spider dragline have been studied and partially clarified, the morphology and elemental contents of the skin layer of silk fibers have not been investigated in detail to date. Here, the surface of Nephila clavata spider dragline was evaluated by field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) to obtain clear surface morphological and molecular information. The FE-SEM images of the spider dragline indicate that the spider dragline forms a bundle of microfibrils. This hierarchical structure might induce faint fibrilar and network-like patterns on the surface of the dragline. XPS analysis revealed the presence of Na, P, and S, which are reasonably explained by considering the biological components of the major ampullate gland of spiders. The results obtained here are preliminary but will be important to consider the molecular transition of silk proteins to form excellent hierarchical structures during the spider dragline spinning process.
Collapse
Affiliation(s)
- Hiromitsu Sogawa
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Kyohei Nakano
- Emergent Functional Polymers Research Team, RIKEN Center for Emergent Matter Science, Saitama, Japan
| | - Ayaka Tateishi
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Keisuke Tajima
- Emergent Functional Polymers Research Team, RIKEN Center for Emergent Matter Science, Saitama, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| |
Collapse
|