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Chi J, Ou Y, Li F, Zhang W, Zhai H, Liu T, Chen Q, Zhou X, Fang L. Cooperative roles of phosphate and dissolved organic matter in inhibiting ferrihydrite transformation and their distinct fates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168376. [PMID: 37952664 DOI: 10.1016/j.scitotenv.2023.168376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/28/2023] [Accepted: 11/04/2023] [Indexed: 11/14/2023]
Abstract
Phosphate and dissolved organic matter (DOM) mediate the crystalline transformation of ferrihydrite catalyzed by Fe(II) in subsurface environments such as soils and groundwater. However, the cooperative mechanisms underlying the mediation of phosphate and DOM in crystalline transformation of ferrihydrite and the feedback effects on their own distribution and speciation remain unresolved. In this study, solid characterization indicates that phosphate and DOM can collectively inhibit the crystalline transformation of ferrihydrite to lepidocrocite and thus goethite, via synergetic effects of inhibiting recrystallization and electron transfer. Phosphate can be retained on the surface or transformed to a nonextractable form within Fe oxyhydroxides; DOM is either released into the solution or preserved in an extractable form, while it is not incorporated or retained in the interior. Element distribution and DOM composition analysis on Fe oxyhydroxides reveals even distribution of phosphate on the newly formed Fe oxyhydroxides, while the distribution of DOM depends on its specific species. Electrochemical and dynamic force spectroscopic results provide molecular-scale thermodynamic evidence explaining the inhibition of electron transfer between Fe(II) and ferrihydrite by phosphate and DOM, thus influecing the crystalline transformation of ferrihydrite and the distribution of phosphate and DOM. This study provides new insights into the coupled biogeological cycle of Fe with phosphate and DOM in aquatic and terrestrial environments.
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Affiliation(s)
- Jialin Chi
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Yanan Ou
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; Beijing Key Laboratory of Farmyard Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Hang Zhai
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Tongxu Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Qing Chen
- Beijing Key Laboratory of Farmyard Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaoxia Zhou
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Liping Fang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
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2
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Cai J, Moradian-Oldak J. Triple Function of Amelogenin Peptide-Chitosan Hydrogel for Dentin Repair. J Dent Res 2023; 102:1434-1443. [PMID: 37880947 PMCID: PMC10767697 DOI: 10.1177/00220345231198228] [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] [Indexed: 10/27/2023] Open
Abstract
Biomimetic strategies like peptide-guided collagen mineralization promise to enhance the effectiveness of dentin remineralization. We recently reported that rationally designed amelogenin-derived peptides P26 and P32 promoted apatite nucleation, mineralized collagen, and showed potential in enamel regrowth and dentin remineralization. To facilitate the clinical application of amelogenin-derived peptides and to uncover their effectiveness in repairing dentin, we have now implemented a chitosan (CS) hydrogel for peptide delivery and have investigated the effects of P26-CS and P32-CS hydrogels on dentin remineralization using 2 in situ experimental models that exhibited different levels of demineralization. The efficacy of the peptide-CS hydrogels in dentin repair was evaluated by characterizing the microstructure, mineral density, mineral phase, and nanomechanical properties of the remineralized samples. The new strategy of atomic force microscopy PeakForce quantitative nanomechanical mapping was used for direct visualization and nanomechanical analysis of repaired dentin lesions across the lesion depth. Results from the 2 models indicated the potential triple functions of peptide-CS hydrogels for dentin repair: building a highly organized protective mineralized layer on dentin, occluding dentinal tubules by peptide-guided in situ mineralization, and promoting biomimetic dentinal collagen remineralization. Importantly, peptides released from the CS hydrogel could diffuse into the dentinal matrix and penetrate the dentinal tubules, leading to both surface and subsurface remineralization and tubule occlusion. Given our previous findings on peptide-CS hydrogels' potential for remineralizing enamel, we see further promise for hydrogels to treat tooth defects involving multiple hard tissues, as in the case of noncarious cervical lesions.
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Affiliation(s)
- J. Cai
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - J. Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
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3
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Zhang T, Wu L, Song Y, Li X, Niu X, Sun Y, Liu J, Feng G, Lei S. Functional Covalent Organic Framework (COF) Nanoparticles for Biomimic Mineralization and Bacteria Inhabitation. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37919250 DOI: 10.1021/acsami.3c13249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Biomimic mineralization of hard tissues with hierarchical structures is a challenging task, while designing multifunctional materials possessing both the ability of biomimic mineralization and drug delivery is even more difficult. Herein, inspired by the multilevel structure and mineralization ability of amelogenin, a novel carboxyl-functionalized covalent organic framework (COF) nanosphere material was designed and synthesized, which exhibited a significant biomimetic remineralization ability as demonstrated on SiO2 glass, Ti6Al4V, and an acid-etched enamel surface. Furthermore, the nanoporous structure also enables the COF nanospheres to serve as a drug delivery system for the controlled release of antibacterial drugs. This work provides a promising strategy for the design of multifunctional biomimic materials.
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Affiliation(s)
- Tian Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Lingli Wu
- Medical College, Northwest Minzu University, Lanzhou 730000, China
| | - Yaru Song
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Xiaojuan Li
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Xinxin Niu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Yajing Sun
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Jie Liu
- Tianjin Key Laboratory of Life and Health Detection, Life and Health Intelligent Research Institute, Tianjin University of Technology, Tianjin 300384, China
| | - Guangyuan Feng
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Shengbin Lei
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
- School of Chemistry and Chemical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
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4
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Akkineni S, Doerk GS, Shi C, Jin B, Zhang S, Habelitz S, De Yoreo JJ. Biomimetic Mineral Synthesis by Nanopatterned Supramolecular-Block Copolymer Templates. NANO LETTERS 2023; 23:4290-4297. [PMID: 37141413 PMCID: PMC10215289 DOI: 10.1021/acs.nanolett.3c00480] [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: 02/06/2023] [Revised: 04/11/2023] [Indexed: 05/06/2023]
Abstract
Supramolecular structures of matrix proteins in mineralizing tissues are known to direct the crystallization of inorganic materials. Here we demonstrate how such structures can be synthetically directed into predetermined patterns for which functionality is maintained. The study employs block copolymer lamellar patterns with alternating hydrophilic and hydrophobic regions to direct the assembly of amelogenin-derived peptide nanoribbons that template calcium phosphate nucleation by creating a low-energy interface. Results show that the patterned nanoribbons retain their β-sheet structure and function and direct the formation of filamentous and plate-shaped calcium phosphate with high fidelity, where the phase, amorphous or crystalline, depends on the choice of mineral precursor and the fidelity depends on peptide sequence. The common ability of supramolecular systems to assemble on surfaces with appropriate chemistry combined with the tendency of many templates to mineralize multiple inorganic materials implies this approach defines a general platform for bottom-up-patterning of hybrid organic-inorganic materials.
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Affiliation(s)
- Susrut Akkineni
- Department
of Materials Science and Engineering, University
of Washington, Seattle, Washington 98195, United States
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Gregory S Doerk
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, 735 Brookhaven Avenue, Upton, New York 11973, United States
| | - Chenyang Shi
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Biao Jin
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Shuai Zhang
- Department
of Materials Science and Engineering, University
of Washington, Seattle, Washington 98195, United States
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Stefan Habelitz
- Department
of Preventive and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, California 94143, United States
| | - James J De Yoreo
- Department
of Materials Science and Engineering, University
of Washington, Seattle, Washington 98195, United States
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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5
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Atomic Details of Biomineralization Proteins Inspiring Protein Design and Reengineering for Functional Biominerals. CHEMISTRY 2022. [DOI: 10.3390/chemistry4030059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Biominerals are extraordinary materials that provide organisms with a variety of functions to support life. The synthesis of biominerals and organization at the macroscopic level is a consequence of the interactions of these materials with proteins. The association of biominerals and proteins is very ancient and has sparked a wealth of research across biological, medical and material sciences. Calcium carbonate, hydroxyapatite, and silica represent widespread natural biominerals. The atomic details of the interface between macromolecules and these biominerals is very intriguing from a chemical perspective, considering the association of chemical entities that are structurally different. With this review I provide an overview of the available structural studies of biomineralization proteins, explored from the Protein Data Bank (wwPDB) archive and scientific literature, and of how these studies are inspiring the design and engineering of proteins able to synthesize novel biominerals. The progression of this review from classical template proteins to silica polymerization seeks to benefit researchers involved in various interdisciplinary aspects of a biomineralization project, who need background information and a quick update on advances in the field. Lessons learned from structural studies are exemplary and will guide new projects for the imaging of new hybrid biomineral/protein superstructures at the atomic level.
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Ge X, Zhang W, Putnis CV, Wang L. Direct observation of humic acid-promoted hydrolysis of phytate through stabilizing a conserved catalytic domain in phytase. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1082-1093. [PMID: 35730733 DOI: 10.1039/d2em00065b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
As a potential phosphorus (P) pool, the enzymatic hydrolysis of organic phosphorus (Po) is of fundamental importance due to the release of bioavailable inorganic phosphate (Pi) for agronomic P sustainability. However, little is known about the role of soil organic matter (SOM) in the hydrolysis process of phytate by phytase and the subsequent chemical behaviors involving the hydrolysis product (Pi) at different soil interfaces. Here, by using liquid-cell atomic force microscopy (AFM), we present a model system to in situ quantify the nucleation kinetics of phytase-released Pi when precipitating with representative soil multivalent cations (Ca2+/Fe3+) on typical soil mineral/organic interfaces in the presence/absence of humic acid (HA), which involves complex phytase-interface-HA interactions. We observed that a higher HA concentration resulted in a faster nucleation rate of amorphous calcium/iron phosphate (ACP/AIP) on bare and organically-coated (-OH/-COOH) mica surfaces compared with the HA-free control. Besides, the nucleation rate of ACP/AIP induced by organic interfaces was much more significant than that induced by clay mineral interfaces. By combining enzyme activity/stability experiments and AFM-based PeakForce quantitative nanomechanical mapping (PF-QNM) measurements, we directly quantified the contribution of noncovalent phytase-HA interaction to the increase in enzymatic activity from complex phytase-interface-HA interactions. Furthermore, the direct complexation of phytase-HA resulted in the stabilization of a conserved active catalytic domain (ACD) in phytase through the enhanced formation of both an ordered, stereochemically-favored catalytic domain and an unordered non-catalytic domain, which was revealed by Raman secondary structure determination. The results provide direct insights into how HA regulates the catalytic activity of phytase controlling Po fates and how soil interfaces determine the behaviors of released Pi to affect its availability, and thereby contribute to P sustainability in soils.
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Affiliation(s)
- Xinfei Ge
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster, Münster 48149, Germany
- School of Molecular and Life Science, Curtin University, Perth 6845, Australia
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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7
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Akkineni S, Zhu C, Chen J, Song M, Hoff SE, Bonde J, Tao J, Heinz H, Habelitz S, De Yoreo JJ. Amyloid-like amelogenin nanoribbons template mineralization via a low-energy interface of ion binding sites. Proc Natl Acad Sci U S A 2022; 119:e2106965119. [PMID: 35522709 PMCID: PMC9172371 DOI: 10.1073/pnas.2106965119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 03/16/2022] [Indexed: 12/02/2022] Open
Abstract
Protein scaffolds direct the organization of amorphous precursors that transform into mineralized tissues, but the templating mechanism remains elusive. Motivated by models for the biomineralization of tooth enamel, wherein amyloid-like amelogenin nanoribbons guide the mineralization of apatite filaments, we investigated the impact of nanoribbon structure, sequence, and chemistry on amorphous calcium phosphate (ACP) nucleation. Using full-length human amelogenin and peptide analogs with an amyloid-like domain, films of β-sheet nanoribbons were self-assembled on graphite and characterized by in situ atomic force microscopy and molecular dynamics simulations. All sequences substantially reduce nucleation barriers for ACP by creating low-energy interfaces, while phosphoserines along the length of the nanoribbons dramatically enhance kinetic factors associated with ion binding. Furthermore, the distribution of negatively charged residues along the nanoribbons presents a potential match to the Ca–Ca distances of the multi-ion complexes that constitute ACP. These findings show that amyloid-like amelogenin nanoribbons provide potent scaffolds for ACP mineralization by presenting energetically and stereochemically favorable templates of calcium phosphate ion binding and suggest enhanced surface wetting toward calcium phosphates in general.
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Affiliation(s)
- Susrut Akkineni
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Cheng Zhu
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Jiajun Chen
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Miao Song
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Samuel E. Hoff
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Johan Bonde
- Division of Pure and Applied Biochemistry, Center for Applied Life Sciences, Lund University, Lund, SE-221 00, Sweden
| | - Jinhui Tao
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Hendrik Heinz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Stefan Habelitz
- Department of Preventative and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, CA 94143
| | - James J. De Yoreo
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
- Physical Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352
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8
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Ge X, Zhang W, Putnis CV, Wang L. Molecular mechanisms for the humic acid-enhanced formation of the ordered secondary structure of a conserved catalytic domain in phytase. Phys Chem Chem Phys 2022; 24:4493-4503. [PMID: 35113120 DOI: 10.1039/d2cp00054g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Changes in the secondary structure of phytase, particularly the conserved active catalytic domain (ACD, SRHGVRAPHD) are extremely important for the varied catalytic activity during hydrolyzing phytate in the presence of humic acid (HA). However, little is known about the molecular-scale mechanisms of how HA influences the secondary structure of ACD found in phytase. First, in situ surface-enhanced Raman spectroscopy (SERS) results show the secondary structure transformation of ACD from the unordered random coil to the ordered β-sheet structure after treatment with HA. Then, we use an atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) technique that can in situ directly probe the single-molecule interaction of ACD with HA and underlying changes in ACD secondary structure in the approach-retraction cycles in real time. Based on the SMFS results, we further detect the HA-enhanced formation of H-bonding between amide groups in the ACD backbone after noncovalently interacting with HA in the absence of phytate. Following the addition of phytate, the calculated contour length (Lc) and the free energies (ΔGb) of functional groups within ACD(-1/2) binding to mica/HA collectively demonstrate the formation of the organized intermediate structural state of ACD following its covalent binding to phytate. These spectroscopic and single-molecule determinations provide the molecular-scale understanding regarding the detailed mechanisms of HA-enhancement of the ordered β-sheet secondary structure of ACD through chemical functionalities in ACD noncovalently interacting with HA. Therefore, we suggest that similar studies of the interactions of other soil enzymes and plant nutrients may reveal predominant roles of dissolved organic matter (DOM) in controlling elemental cycling and fate for sustainable agriculture development.
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Affiliation(s)
- Xinfei Ge
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster, 48149 Münster, Germany.,School of Molecular and Life Science, Curtin University, Perth 6845, Australia
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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9
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Chen J, Huang Z, Wang F, Gong M, Zhang X, Wang Y, Hu Z, Zeng Z, Wang Y. The restricted adhesion of bone marrow mesenchymal stem cells by stepped structures on surfaces of hydroxyapatite. RSC Adv 2022; 12:12002-12010. [PMID: 35481104 PMCID: PMC9019829 DOI: 10.1039/d2ra00756h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/09/2022] [Indexed: 01/27/2023] Open
Abstract
Currently, many researches have developed several strategies to design the surface structures of hydroxyapatite (HA), and have proved that the surface structures are pivotal in guiding the adhesion of bone marrow mesenchymal stem cells (BMSCs) as well as subsequent cellular behaviours. Most of these strategies, such as altering roughness and constructing surface patterning of HA, involve the construction of geometric topographies at the micro/nanoscale. However, besides geometric topographies, crystal defects are also important characteristics of surface structures and would alter many local physicochemical properties, which is critical for contact between cells and bioceramic surfaces. For the practical applications of crystal defects, a major hindrance is that crystal defects are usually unstable and easily eliminated during crystallization, which limits the large-scale fabrication of materials with crystal defects. In this work, given that stepped structures contain massive stable crystal defects on their step edges and kinks, we proposed a feasible and efficient method to fabricate HA dishes with stepped structures on their surfaces. First, plate-like HA mesocrystals were prepared from CaHPO4via topotactic transformation, and were shaped into HA dishes by vacuum-filtration. Then, a sintering process was applied to facilitate the formation of stepped structures on the surfaces. We demonstrated that the generation of stepped structures could restrict the adhesion of BMSCs and showed the restriction effect is highly correlated with the density of exposed stepped structures. This phenomenon is interesting and the construction of a cell adhesion model is robust and easy, the underlying mechanisms of which deserve further exploration. Furthermore, constructing stepped structures on surfaces may be a new useful strategy to regulate cell adhesion and could also cooperate with other methods that do not need change in the surface crystal structure. Stepped structures largely exposed on surfaces of HA significantly restrict the adhesion of bone marrow mesenchymal stem cells.![]()
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Affiliation(s)
- Jin Chen
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
- Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Zhuo Huang
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Fang Wang
- Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Min Gong
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Xueli Zhang
- Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Yajing Wang
- The Affiliated Stomatological Hospital of Guizhou Medical University, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Zuquan Hu
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Zhu Zeng
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
- Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025, P. R. China
| | - Yun Wang
- Key Laboratory of Biology and Medical Engineering/Immune Cells and Antibody Engineering Research Center of Guizhou Province, School of Biology and Engineering, Guizhou Medical University, Guiyang, 550025, P. R. China
- Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025, P. R. China
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10
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Acero PN, Mohr S, Bernabei M, Fernández C, Domínguez B, Ewen JP. Molecular Simulations of Surfactant Adsorption on Iron Oxide from Hydrocarbon Solvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14582-14596. [PMID: 34878282 DOI: 10.1021/acs.langmuir.1c02133] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The performance of organic friction modifiers (OFMs) depends on their ability to adsorb onto surfaces and form protective monolayers. Understanding the relationship between OFM concentration in the base oil and the resulting surface coverage is important for improving lubricant formulations. Here, we use molecular dynamics (MD) simulations to study the adsorption of three OFMs─stearic acid (SA), glycerol monoostearate (GMS), and glycerol monooleate (GMO)─onto a hematite surface from two hydrocarbon solvents─n-hexadecane and poly(α-olefin) (PAO). We calculate the potential of mean force of the adsorption process using the adaptive biasing force algorithm, and the adsorption strength increases in the order SA < GMS < GMO. We estimate the minimum area occupied by OFM molecules on the surface using annealing MD simulations and obtained a similar hard-disk area for GMS and GMO but a lower value for SA. Using the MD results, we determine the adsorption isotherms using the molecular thermodynamic theory (MTT), which agree well with one previous experimental data set for SA on hematite. For two other experimental data sets for SA, lateral interactions between surfactant molecules need to be accounted for within the MTT framework. SA forms monolayers with lower surface coverage than GMO and GMS at low concentrations but also has the highest plateau coverage. We validate the adsorption energies from the MD simulations using high-frequency reciprocating rig friction experiments with different concentrations of the OFMs in PAO. For OFMs with saturated tailgroups (SA and GMS), we obtain good agreement between the simulations and the experiments. The results deviate for OFMs containing Z-unsaturated tailgroups (GMO) due to the additional steric hindrance, which is not accounted for in the current simulation framework. This study demonstrates that MD simulations, alongside MTT, are an accurate and efficient tool to predict adsorption isotherms at solid-liquid interfaces.
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Affiliation(s)
- Pablo Navarro Acero
- Nextmol (Bytelab Solutions SL), Carrer de Roc Boronat 117, 08 018 Barcelona, Spain
- Barcelona Supercomputing Center (BSC-CNS), Plaça Eusebi Güell, 1-3, 08 034 Barcelona, Spain
| | - Stephan Mohr
- Nextmol (Bytelab Solutions SL), Carrer de Roc Boronat 117, 08 018 Barcelona, Spain
- Barcelona Supercomputing Center (BSC-CNS), Plaça Eusebi Güell, 1-3, 08 034 Barcelona, Spain
| | - Marco Bernabei
- Repsol Technology Lab, DC Technology & Corporate Venturing, Agustín de Betancourt s/n, 28 935 Mostoles, Madrid, Spain
| | - Carlos Fernández
- Repsol Technology Lab, DC Technology & Corporate Venturing, Agustín de Betancourt s/n, 28 935 Mostoles, Madrid, Spain
| | - Beatriz Domínguez
- Repsol Technology Lab, DC Technology & Corporate Venturing, Agustín de Betancourt s/n, 28 935 Mostoles, Madrid, Spain
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
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11
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Abstract
Biomineralization of enamel, dentin, and bone involves the deposition of apatite mineral crystals within an organic matrix. Bone and teeth are classic examples of biomaterials with unique biomechanical properties that are crucial to their function. The collagen-based apatite mineralization and the important function of noncollagenous proteins are similar in dentin and bone; however, enamel is formed in a unique amelogenin-containing protein matrix. While the structure and organic composition of enamel are different from those of dentin and bone, the principal molecular mechanisms of protein-protein interactions, protein self-assembly, and control of crystallization events by the organic matrix are common among these apatite-containing tissues. This review briefly summarizes enamel and dentin matrix components and their interactions with other extracellular matrix components and calcium ions in mediating the mineralization process. We highlight the crystallization events that are controlled by the protein matrix and their interactions in the extracellular matrix during enamel and dentin biomineralization. Strategies for peptide-inspired biomimetic growth of tooth enamel and bioinspired mineralization of collagen to stimulate repair of demineralized dentin and bone tissue engineering are also addressed.
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Affiliation(s)
- J Moradian-Oldak
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - A George
- Brodie Tooth Development Genetics & Regenerative Medicine Research Laboratory, Department of Oral Biology, University of Illinois at Chicago, Chicago, IL, USA
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12
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Hoff SE, Liu J, Heinz H. Binding mechanism and binding free energy of amino acids and citrate to hydroxyapatite surfaces as a function of crystallographic facet, pH, and electrolytes. J Colloid Interface Sci 2021; 605:685-700. [PMID: 34365305 DOI: 10.1016/j.jcis.2021.07.109] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022]
Abstract
Hydroxyapatite (HAP) is the major mineral phase in bone and teeth. The interaction of individual amino acids and citrate ions with different crystallographic HAP surfaces has remained uncertain for decades, creating a knowledge gap to rationally design interactions with peptides, proteins, and drugs. In this contribution, we quantify the binding mechanisms and binding free energies of the 20 end-capped natural amino acids and citrate ions on the basal (001) and prismatic (010)/(020) planes of hydroxyapatite at pH values of 7 and 5 for the first time at the molecular scale. We utilized over 1500 steered molecular dynamics simulations with highly accurate potentials that reproduce surface and hydration energies of (hkl) hydroxyapatite surfaces at different pH values. Charged residues demonstrate a much higher affinity to HAP than charge-neutral species due to the formation of superficial ion pairs and ease of penetration into layers of water molecules on the mineral surface. Binding free energies range from 0 to -60 kJ/mol and were determined with ∼ 10% uncertainty. The highest affinity was found for citrate, followed by Asp(-) and Glu(-), and followed after a gap by Arg(+), Lys(+), as well as by His(+) at pH 5. The (hkl)-specific area density of calcium ions, the protonation state of phosphate ions, and subsurface directional order of the ions in HAP lead to surface-specific binding patterns. Amino acids without ionic side groups exhibit weak binding, between -3 and 0 kJ/mol, due to difficulties to penetrate the first layer of water molecules on the apatite surfaces. We explain recognition processes that remained elusive in experiments, in prior simulations, discuss agreement with available data, and reconcile conflicting interpretations. The findings can serve as useful input for the design of peptides, proteins, and drug molecules for the modification of bone and teeth-related materials, as well as control of apatite mineralization.
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Affiliation(s)
- Samuel E Hoff
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Juan Liu
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA; Department of Materials Science and Engineering, Dalian Maritime University, Dalian, Liaoning 116026, China
| | - Hendrik Heinz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA.
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13
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Alvisi N, Gutiérrez-Mejía FA, Lokker M, Lin YT, de Jong AM, van Delft F, de Vries R. Self-Assembly of Elastin-like Polypeptide Brushes on Silica Surfaces and Nanoparticles. Biomacromolecules 2021; 22:1966-1979. [PMID: 33871996 PMCID: PMC8154268 DOI: 10.1021/acs.biomac.1c00067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Control over the placement and activity of biomolecules on solid surfaces is a key challenge in bionanotechnology. While covalent approaches excel in performance, physical attachment approaches excel in ease of processing, which is equally important in many applications. We show how the precision of recombinant protein engineering can be harnessed to design and produce protein-based diblock polymers with a silica-binding and highly hydrophilic elastin-like domain that self-assembles on silica surfaces and nanoparticles to form stable polypeptide brushes that can be used as a scaffold for later biofunctionalization. From atomic force microscopy-based single-molecule force spectroscopy, we find that individual silica-binding peptides have high unbinding rates. Nevertheless, from quartz crystal microbalance measurements, we find that the self-assembled polypeptide brushes cannot easily be rinsed off. From atomic force microscopy imaging and bulk dynamic light scattering, we find that the binding to silica induces fibrillar self-assembly of the peptides. Hence, we conclude that the unexpected stability of these self-assembled polypeptide brushes is at least in part due to peptide-peptide interactions of the silica-binding blocks at the silica surface.
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Affiliation(s)
- Nicolò Alvisi
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, Wageningen 6708 WE, The Netherlands
| | - Fabiola A Gutiérrez-Mejía
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, Wageningen 6708 WE, The Netherlands
| | - Meike Lokker
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, Wageningen 6708 WE, The Netherlands
| | - Yu-Ting Lin
- Department of Applied Physics and Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Arthur M de Jong
- Department of Applied Physics and Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Floris van Delft
- Laboratory of Organic Chemistry, Wageningen University and Research, Stippeneng 4, Wageningen 6708 WE, The Netherlands
| | - Renko de Vries
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, Wageningen 6708 WE, The Netherlands
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14
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Wang D, Deng J, Deng X, Fang C, Zhang X, Yang P. Controlling Enamel Remineralization by Amyloid-Like Amelogenin Mimics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002080. [PMID: 32583928 DOI: 10.1002/adma.202002080] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/16/2020] [Indexed: 06/11/2023]
Abstract
In situ regeneration of the enamel-like structure of hydroxyapatite (HAp) crystals under oral conditions is significant for dental caries treatment. However, it is still a challenge for dentists to duplicate the elegant and well-aligned apatite structure bonding to the surface of demineralized enamel. A biocompatible amelogenin-inspired matrix, a phase-transited lysozyme (PTL) film mimicking an N-terminal amelogenin with central domain (N-Ame) combined with synthetic peptide (C-AMG) based on the functional domains of C-terminal telopeptide (C-Ame) is shown here, which is formed by amyloid-like lysozyme aggregation at the enamel interface through a rapid one-step aqueous coating process. In the PTL/C-AMG matrix, C-AMG facilitated the oriented arrangement of amorphous calcium phosphate (ACP) nanoparticles and their transformation to ordered enamel-like HAp crystals, while PTL served as a strong interfacial anchor to immobilize the C-AMG peptide and PTL/C-AMG matrix on versatile substrate surfaces. PTL/C-AMG film-coated enamel induced both of the in vivo and in vitro synthesis of HAp crystals, facilitated epitaxial growth of HAp crystals and recovered the highly oriented structure and mechanical properties to levels nearly identical to those of natural enamel. This work underlines the importance of amyloid-like protein aggregates in the biomineralization of enamel, providing a promising strategy for treating dental caries.
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Affiliation(s)
- Dong Wang
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, 710048, China
| | - Jingjing Deng
- School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin, 30070, China
| | - Xuliang Deng
- Department of Geriatric Dentistry, School and Hospital of Stomatology, Peking University, 22 Zhongguancun South Street, Beijing, 100081, China
| | - Changqing Fang
- School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, 710048, China
- The Faculty of Printing, Packaging Engineering and Digital Media Technology, Xi'an University of Technology, Xi'an, 710048, China
| | - Xu Zhang
- School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin, 30070, China
| | - Peng Yang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
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15
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Zhang J, Wang L, Zhang W, Putnis CV. Phosphorylated/Nonphosphorylated Motifs in Amelotin Turn Off/On the Acidic Amorphous Calcium Phosphate-to-Apatite Phase Transformation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2102-2109. [PMID: 32036670 DOI: 10.1021/acs.langmuir.9b02735] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Amelotin (AMTN) as a matrix protein exerts a direct effect on biomineralization by modulating apatite (HAP) formation during the dental enamel maturation stage through the specific interaction of a potentially phosphorylated Ser-Ser-Glu-Glu-Leu (SSEEL) peptide fragment with calcium phosphate (Ca-P) surfaces. However, the roles of (non)phosphorylation of this evolutionarily conserved subdomain within AMTN remain poorly understood. Here, we show, by time-resolved atomic force microscopy (AFM) imaging of in situ HAP crystallization via the HPO42--rich amorphous calcium phosphate (acidic ACP), the on/off switching of the phase transformation process through a nonphosphorylation-to-phosphorylation transition of the SSEEL motif. Using high-resolution transmission electron microscopy (HRTEM), we observed that the acidic ACP phase is stabilized by the phosphorylated SSEEL motif, delaying its transformation to HAP, whereas the nonphosphorylated counterpart promotes HAP formation by accelerating the dissolution-recrystallization of the acidic ACP substrate. Dynamic force spectroscopy measurements demonstrate greater binding energies of nonphosphorylated SSEEL to the acidic ACP substrate by the formation of molecular peptide-ACP bonding, explaining the enhanced dissolution of the acidic ACP substrate by stronger complexion with surface Ca2+ ions. Our findings demonstrate direct evidence for the switching role of (non)phosphorylation of an evolutionarily conserved subdomain within AMTN in controlling the phase transition of growing enamel and designing tissue regeneration biomaterials.
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Affiliation(s)
- Jing Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster, 48149 Münster, Germany
- Department of Chemistry, Curtin University, Perth 6845, Australia
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16
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Šupová M. The Significance and Utilisation of Biomimetic and Bioinspired Strategies in the Field of Biomedical Material Engineering: The Case of Calcium Phosphat-Protein Template Constructs. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E327. [PMID: 31936830 PMCID: PMC7013803 DOI: 10.3390/ma13020327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/03/2020] [Accepted: 01/07/2020] [Indexed: 02/07/2023]
Abstract
This review provides a summary of recent research on biomimetic and bioinspired strategies applied in the field of biomedical material engineering and focusing particularly on calcium phosphate-protein template constructs inspired by biomineralisation. A description of and discussion on the biomineralisation process is followed by a general summary of the application of the biomimetic and bioinspired strategies in the fields of biomedical material engineering and regenerative medicine. Particular attention is devoted to the description of individual peptides and proteins that serve as templates for the biomimetic mineralisation of calcium phosphate. Moreover, the review also presents a description of smart devices including delivery systems and constructs with specific functions. The paper concludes with a summary of and discussion on potential future developments in this field.
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Affiliation(s)
- Monika Šupová
- Department of Composites and Carbon Materials, Institute of Rock Structure and Mechanics, The Czech Academy of Sciences, V Holešovičkách 41, 182 09 Prague, Czech Republic
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17
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Tokunou Y, Okamoto A. Geometrical Changes in the Hemes of Bacterial Surface c-Type Cytochromes Reveal Flexibility in Their Binding Affinity with Minerals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7529-7537. [PMID: 30351954 DOI: 10.1021/acs.langmuir.8b02977] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Microbial extracellular electron transport occurs via the physical and electrical association of outer-membrane c-type cytochromes (OM c-Cyts) with extracellular solid surfaces. However, studies investigating the characteristics of cytochrome binding with solid materials have been limited to the use of purified units of OM c-Cyts dissolved in solution, rather than OM c-Cyts in intact cells, because of the lack of a methodology that specifically allows for the monitoring of OM c-Cyts in whole-cells. Here, we utilized circular dichroism (CD) spectroscopy to examine the molecular mechanisms and binding characteristics of the interaction between MtrC, a unit of OM c-Cyts, in whole Shewanella oneidensis MR-1 cells and hematite nanoparticles. The addition of hematite nanoparticles significantly decreased the intensity of the Soret CD peaks, indicating geometrical changes in the hemes in MtrC associated with their physical contact with hematite. The binding affinity of MtrC estimated using CD spectra changed predominantly depending upon the redox state of MtrC and the concentration of the hematite nanoparticles. In contrast, purified MtrC demonstrated a constant binding affinity following a Langmuir isotherm, with a standard Gibbs free energy of -43 kJ mol-1, suggesting that the flexibility in the binding affinity of MtrC with hematite was specific in membrane-bound protein complex conditions. Overall, these findings suggest that the binding affinity as well as the heme geometry of OM c-Cyts are flexibly modulated in the membrane complex associated with microbe-mineral interactions.
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Affiliation(s)
- Yoshihide Tokunou
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8656 , Japan
- International Center for Materials Nanoarchitectonics , National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Akihiro Okamoto
- International Center for Materials Nanoarchitectonics , National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
- Center for Functional Sensor & Actuator , National Institute for Materials Science , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
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18
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Zhai H, Qin L, Zhang W, Putnis CV, Wang L. Dynamics and Molecular Mechanism of Phosphate Binding to a Biomimetic Hexapeptide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10472-10479. [PMID: 30138561 DOI: 10.1021/acs.est.8b03062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Phosphorus (P) recovery from wastewater is essential for sustainable P management. A biomimetic hexapeptide (SGAGKT) has been demonstrated to bind inorganic P in P-rich environments, however the dynamics and molecular mechanisms of P-binding to the hexapeptide still remain largely unknown. We used dynamic force spectroscopy (DFS) to directly distinguish the P-unbound and P-bound SGAGKT adsorbed to a mica (001) surface by measuring the single-molecule binding free energy (Δ Gb). Using atomic force microscopy (AFM) to determine real-time step retreat velocities of triangular etch pits formed at the nanoscale on the dissolving (010) face of brushite (CaHPO4·2H2O) in the presence of SGAGKT, we observed that SGAGKT peptides promoted in situ dissolution through an enhanced P-binding driven by hydrogen bonds in a P-loop being capable of discriminating phosphate over arsenate, concomitantly forming a thermodynamically favored SGAGKT-HPO42- complexation at pH 8.0 and relatively low ionic strength, consistent with the DFS and isothermal titration calorimetry (ITC) determinations. The findings reveal the thermodynamic and kinetic basis for binding of phosphate to SGAGKT and provide direct evidence for phosphate discrimination in phosphate/arsenate-rich environments.
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Affiliation(s)
- Hang Zhai
- College of Resources and Environment , Huazhong Agricultural University , Wuhan 430070 , China
| | - Lihong Qin
- College of Resources and Environment , Huazhong Agricultural University , Wuhan 430070 , China
| | - Wenjun Zhang
- College of Resources and Environment , Huazhong Agricultural University , Wuhan 430070 , China
| | - Christine V Putnis
- Institut für Mineralogie , University of Münster , 48149 Münster , Germany
- Department of Chemistry , Curtin University , Perth , WA6845 , Australia
| | - Lijun Wang
- College of Resources and Environment , Huazhong Agricultural University , Wuhan 430070 , China
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19
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Kumar M, Choudhary MK, Rimer JD. Transient modes of zeolite surface growth from 3D gel-like islands to 2D single layers. Nat Commun 2018; 9:2129. [PMID: 29844357 PMCID: PMC5974312 DOI: 10.1038/s41467-018-04296-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 04/10/2018] [Indexed: 11/09/2022] Open
Abstract
Zeolite crystallization occurs by multifaceted processes involving molecule attachment and nonclassical pathways governed by the addition of amorphous precursors. Here, we use scanning probe microscopy to monitor zeolite LTA crystallization in situ with a spatiotemporal resolution that captures dynamic processes in real time. We report a distinctive pathway involving the formation of gel-like islands from supersaturated solutions comprised of (alumino)silicate molecules. Three-dimensional assembly and evolution of these islands constitutes a unique mode of growth that differs from classical theories. Time-resolved imaging also reveals that growth can occur by (nearly) oriented attachment. At later stages of crystallization, a progressive transition to lower supersaturation shifts growth to a layered mechanism involving two-dimensional nucleation and spreading of layers. Here, we show that LTA crystallization occurs by multiple pathways, thereby reconciling putative hypotheses of growth mechanisms while also highlighting new modes of nonclassical crystallization that may prove relevant to other zeolites and related materials.
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Affiliation(s)
- Manjesh Kumar
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA
| | - Madhuresh K Choudhary
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA
| | - Jeffrey D Rimer
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX, 77204, USA.
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20
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Lubin JH, Pacella MS, Gray JJ. A Parametric Rosetta Energy Function Analysis with LK Peptides on SAM Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5279-5289. [PMID: 29630384 DOI: 10.1021/acs.langmuir.8b00212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Although structures have been determined for many soluble proteins and an increasing number of membrane proteins, experimental structure determination methods are limited for complexes of proteins and solid surfaces. An economical alternative or complement to experimental structure determination is molecular simulation. Rosetta is one software suite that models protein-surface interactions, but Rosetta is normally benchmarked on soluble proteins. For surface interactions, the validity of the energy function is uncertain because it is a combination of independent parameters from energy functions developed separately for solution proteins and mineral surfaces. Here, we assess the performance of the RosettaSurface algorithm and test the accuracy of its energy function by modeling the adsorption of leucine/lysine (LK)-repeat peptides on methyl- and carboxy-terminated self-assembled monolayers (SAMs). We investigated how RosettaSurface predictions for this system compare with the experimental results, which showed that on both surfaces, LK-α peptides folded into helices and LK-β peptides held extended structures. Utilizing this model system, we performed a parametric analysis of Rosetta's Talaris energy function and determined that adjusting solvation parameters offered improved predictive accuracy. Simultaneously increasing lysine carbon hydrophilicity and the hydrophobicity of the surface methyl head groups yielded computational predictions most closely matching the experimental results. De novo models still should be interpreted skeptically unless bolstered in an integrative approach with experimental data.
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21
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Mukherjee K, Ruan Q, Nutt S, Tao J, De Yoreo JJ, Moradian-Oldak J. Peptide-Based Bioinspired Approach to Regrowing Multilayered Aprismatic Enamel. ACS OMEGA 2018; 3:2546-2557. [PMID: 29623301 PMCID: PMC5879487 DOI: 10.1021/acsomega.7b02004] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 02/22/2018] [Indexed: 05/28/2023]
Abstract
The gradual discovery of functional domains in native enamel matrix proteins has enabled the design of smart bioinspired peptides for tooth enamel mimetics and repair. In this study, we expanded upon the concept of biomineralization to design smaller amelogenin-inspired peptides with conserved functional domains for clinical translation. The synthetic peptides displayed a characteristic nanostructured scaffold reminiscent of 'nanospheres' seen in the enamel matrix and effectively controlled apatite nucleation in vitro resulting in the formation of smaller crystallites. Following application of the peptides to sectioned human molar teeth, a robust, oriented, synthetic aprismatic enamel was observed after 7 days of incubation in situ. There was a two-fold increase in the hardness and modulus of the regrown enamel-like apatite layers and an increase in the attachment of the tooth-regrown layer interface compared to control samples. Repeated peptide applications generated multiple enamel-like hydroxyapatite (HAP) layers of limited thickness produced by epitaxial growth in which c-axis oriented nanorods evolved on the surface of native enamel. We conclude that peptide analogues with active domains can effectively regulate the orientation of regenerated HAP layers to influence functional response. Moreover, this enamel biofabrication approach demonstrates the peptide-mediated growth of multiple microscale HAP arrays of organized microarchitecture with potential for enamel repair.
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Affiliation(s)
- Kaushik Mukherjee
- Center
for Craniofacial Molecular Biology, Division of Biomedical Sciences,
Herman Ostrow School of Dentistry, University
of Southern California, 2250 Alcazar Street, 90033 Los Angeles, United States
| | - Qichao Ruan
- Center
for Craniofacial Molecular Biology, Division of Biomedical Sciences,
Herman Ostrow School of Dentistry, University
of Southern California, 2250 Alcazar Street, 90033 Los Angeles, United States
| | - Steven Nutt
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, 3651 Watt Way, 90089 Los Angeles, United States
| | - Jinhui Tao
- Physical
Sciences Division, Pacific Northwest National
Laboratory, 902 Battelle
Blvd, 99352 Richland, United States
| | - James J. De Yoreo
- Physical
Sciences Division, Pacific Northwest National
Laboratory, 902 Battelle
Blvd, 99352 Richland, United States
| | - Janet Moradian-Oldak
- Center
for Craniofacial Molecular Biology, Division of Biomedical Sciences,
Herman Ostrow School of Dentistry, University
of Southern California, 2250 Alcazar Street, 90033 Los Angeles, United States
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22
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Li M, Wang L, Putnis CV. Atomic force microscopy imaging of classical and nonclassical surface growth dynamics of calcium orthophosphates. CrystEngComm 2018. [DOI: 10.1039/c7ce02100c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This review highlights in situ atomic force microscopy observations of the classical and nonclassical surface growth dynamics of calcium orthophosphates.
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Affiliation(s)
- Meng Li
- College of Resources and Environment
- Huazhong Agricultural University
- Wuhan 430070
- China
| | - Lijun Wang
- College of Resources and Environment
- Huazhong Agricultural University
- Wuhan 430070
- China
| | - Christine V. Putnis
- Institut für Mineralogie
- University of Münster
- 48149 Münster
- Germany
- Department of Chemistry
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23
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Xue Z, Shen Q, Liang L, Shen JW, Wang Q. Adsorption Behavior and Mechanism of SCA-1 on a Calcite Surface: A Molecular Dynamics Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11321-11331. [PMID: 28666388 DOI: 10.1021/acs.langmuir.7b01217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The crystallization mechanism for natural mineral, especially the role of biological molecules in biomineralization, is still under debate. Protein adsorption on material surfaces plays a key role in biomineralization. In this article, molecular dynamics (MD) simulations were performed to systematically investigate the adsorption behavior of struthio camelus eggshell protein struthiocalcin-1 (SCA-1) on the calcite (104) surface with several different starting orientations in an explicit water environment. For each binding configuration, detailed adsorption behaviors and a mechanism were presented with the analysis of interaction energy, binding residues, hydrogen bonding, and structures (such as DSSP, dipole moment, and the electrostatic potential calculation). The results indicate that the positively charged and polar residues are the dominant residues for protein adsorption on the calcite (104) surface, and the strong electrostatic interaction drives the binding of model protein to the surface. The hydrogen bond bridge was found to play an important role in surface interactions as well. These results also demonstrate that SCA-1 is relatively rigid in spite of strong adsorption with few structural changes in α-helix and β-sheet contents. The results of the orientation calculation suggest that the dipole moment of the protein tends to remain parallel to calcite in most stable cases, which was confirmed by electrostatic potential isosurfaces analysis.
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Affiliation(s)
- Zhengyang Xue
- Department of Chemistry, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Qiying Shen
- School of Medicine, Hangzhou Normal University , Hangzhou 310016, People's Republic of China
| | - Lijun Liang
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University , Hangzhou, People's Republic of China
| | - Jia-Wei Shen
- School of Medicine, Hangzhou Normal University , Hangzhou 310016, People's Republic of China
| | - Qi Wang
- Department of Chemistry, Zhejiang University , Hangzhou 310027, People's Republic of China
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24
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Pandya M, Lin T, Li L, Allen MJ, Jin T, Luan X, Diekwisch TGH. Posttranslational Amelogenin Processing and Changes in Matrix Assembly during Enamel Development. Front Physiol 2017; 8:790. [PMID: 29089900 PMCID: PMC5651044 DOI: 10.3389/fphys.2017.00790] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/26/2017] [Indexed: 01/20/2023] Open
Abstract
The extracellular tooth enamel matrix is a unique, protein-rich environment that provides the structural basis for the growth of long and parallel oriented enamel crystals. Here we have conducted a series of in vivo and in vitro studies to characterize the changes in matrix shape and organization that take place during the transition from ameloblast intravesicular matrices to extracellular subunit compartments and pericrystalline sheath proteins, and correlated these changes with stages of amelogenin matrix protein posttranslational processing. Our transmission electron microscopic studies revealed a 2.5-fold difference in matrix subunit compartment dimensions between secretory vesicle and extracellular enamel protein matrix as well as conformational changes in matrix structure between vesicles, stippled materials, and pericrystalline matrix. Enamel crystal growth in organ culture demonstrated granular mineral deposits associated with the enamel matrix framework, dot-like mineral deposits along elongating initial enamel crystallites, and dramatic changes in enamel matrix configuration following the onset of enamel crystal formation. Atomic force micrographs provided evidence for the presence of both linear and hexagonal/ring-shaped full-length recombinant amelogenin protein assemblies on mica surfaces, while nickel-staining of the N-terminal amelogenin N92 His-tag revealed 20 nm diameter oval and globular amelogenin assemblies in N92 amelogenin matrices. Western blot analysis comparing loosely bound and mineral-associated protein fractions of developing porcine enamel organs, superficial and deep enamel layers demonstrated (i) a single, full-length amelogenin band in the enamel organ followed by 3 kDa cleavage upon entry into the enamel layer, (ii) a close association of 8–16 kDa C-terminal amelogenin cleavage products with the growing enamel apatite crystal surface, and (iii) a remaining pool of N-terminal amelogenin fragments loosely retained between the crystalline phases of the deep enamel layer. Together, our data establish a temporo-spatial correlation between amelogenin protein processing and the changes in enamel matrix configuration that take place during the transition from intracellular vesicle compartments to extracellular matrix assemblies and the formation of protein coats along elongating apatite crystal surfaces. In conclusion, our study suggests that enzymatic cleavage of the amelogenin enamel matrix protein plays a key role in the patterning of the organic matrix framework as it affects enamel apatite crystal growth and habit.
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Affiliation(s)
- Mirali Pandya
- Texas A&M Center for Craniofacial Research and Diagnosis, Dallas, TX, United States
| | - Tiffani Lin
- UCLA School of Dentistry, Los Angeles, CA, United States.,Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
| | - Leo Li
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States.,University of Michigan Medical School, Ann Arbor, MI, United States
| | | | - Tianquan Jin
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States.,Biocytogen, Worcester, MA, United States
| | - Xianghong Luan
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
| | - Thomas G H Diekwisch
- Texas A&M Center for Craniofacial Research and Diagnosis, Dallas, TX, United States.,Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
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25
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Srinivasan K, Banerjee S, Parimal S, Sejergaard L, Berkovich R, Barquera B, Garde S, Cramer SM. Single Molecule Force Spectroscopy and Molecular Dynamics Simulations as a Combined Platform for Probing Protein Face-Specific Binding. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10851-10860. [PMID: 28949551 DOI: 10.1021/acs.langmuir.7b03011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Biomolecular interactions frequently occur in orientation-specific manner. For example, prior nuclear magnetic resonance spectroscopy experiments in our lab have suggested the presence of a group of strongly binding residues on a particular face of the protein ubiquitin for interactions with Capto MMC multimodal ligands ("Capto" ligands) (Srinivasan, K.; et al. Langmuir 2014, 30 (44), 13205-13216). We present a clear confirmation of those studies by performing single-molecule force spectroscopy (SMFS) measurements of unbinding complemented with molecular dynamics (MD) calculations of the adsorption free energy of ubiquitin in two distinct orientations with self-assembled monolayers (SAMs) functionalized with "Capto" ligands. These orientations were maintained in the SMFS experiments by tethering ubiquitin mutants to SAM surfaces through strategically located cysteines, thus exposing the desired faces of the protein. Analogous orientations were maintained in MD simulations using suitable constraining methods. Remarkably, despite differences between the finer details of experimental and simulation methodologies, they confirm a clear preference for the previously hypothesized binding face of ubiquitin. Furthermore, MD simulations provided significant insights into the mechanism of protein binding onto this multimodal surface. Because SMFS and MD simulations both directly probe protein-surface interactions, this work establishes a key link between experiments and simulations at molecular scale through the determination of protein face-specific binding energetics. Our approach may have direct applications in biophysical systems where face- or orientation-specific interactions are important, such as biomaterials, sensors, and biomanufacturing.
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Affiliation(s)
- Kartik Srinivasan
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Suvrajit Banerjee
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Siddharth Parimal
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Lars Sejergaard
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Ronen Berkovich
- Department of Chemical Engineering, Ben-Gurion University , Beer-Sheva 84105, Israel
| | - Blanca Barquera
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Department of Biology, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Shekhar Garde
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Steven M Cramer
- Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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26
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Fukushima T, Gupta S, Rad B, Cornejo JA, Petzold CJ, Chan LJG, Mizrahi RA, Ralston CY, Ajo-Franklin CM. The Molecular Basis for Binding of an Electron Transfer Protein to a Metal Oxide Surface. J Am Chem Soc 2017; 139:12647-12654. [DOI: 10.1021/jacs.7b06560] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Tatsuya Fukushima
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sayan Gupta
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Behzad Rad
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jose A. Cornejo
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Christopher J. Petzold
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Leanne Jade G. Chan
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Rena A. Mizrahi
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Corie Y. Ralston
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Caroline M. Ajo-Franklin
- Molecular Foundry, Molecular
Biophysics and Integrated Biosciences, and Biological Systems and
Engineering Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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27
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Newcomb CJ, Qafoku NP, Grate JW, Bailey VL, De Yoreo JJ. Developing a molecular picture of soil organic matter-mineral interactions by quantifying organo-mineral binding. Nat Commun 2017; 8:396. [PMID: 28855506 PMCID: PMC5577185 DOI: 10.1038/s41467-017-00407-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 06/27/2017] [Indexed: 01/13/2023] Open
Abstract
Long residence times of soil organic matter have been attributed to reactive mineral surface sites that sorb organic species and cause inaccessibility due to physical isolation and chemical stabilization at the organic–mineral interface. Instrumentation for probing this interface is limited. As a result, much of the micron- and molecular-scale knowledge about organic–mineral interactions remains largely qualitative. Here we report the use of force spectroscopy to directly measure the binding between organic ligands with known chemical functionalities and soil minerals in aqueous environments. By systematically studying the role of organic functional group chemistry with model minerals, we demonstrate that chemistry of both the organic ligand and mineral contribute to values of binding free energy and that changes in pH and ionic strength produce significant differences in binding energies. These direct measurements of molecular binding provide mechanistic insights into organo–mineral interactions, which could potentially inform land-carbon models that explicitly include mineral-bound C pools. Most molecular scale knowledge on soil organo–mineral interactions remains qualitative due to instrument limitations. Here, the authors use force spectroscopy to directly measure free binding energy between organic ligands and minerals and find that both chemistry and environmental conditions affect binding.
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Affiliation(s)
- C J Newcomb
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA
| | - N P Qafoku
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA
| | - J W Grate
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA
| | - V L Bailey
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA
| | - J J De Yoreo
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA. .,Department of Materials Science and Engineering, University of Washington, 302 Roberts Hall, Seattle, Washington, 98195, USA.
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28
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Lacruz RS, Habelitz S, Wright JT, Paine ML. DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE. Physiol Rev 2017; 97:939-993. [PMID: 28468833 DOI: 10.1152/physrev.00030.2016] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
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Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Stefan Habelitz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - J Timothy Wright
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Michael L Paine
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
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29
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Ma X, Zhang S, Jiao F, Newcomb CJ, Zhang Y, Prakash A, Liao Z, Baer MD, Mundy CJ, Pfaendtner J, Noy A, Chen CL, De Yoreo JJ. Tuning crystallization pathways through sequence engineering of biomimetic polymers. NATURE MATERIALS 2017; 16:767-774. [PMID: 28414316 DOI: 10.1038/nmat4891] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 03/09/2017] [Indexed: 06/07/2023]
Abstract
Two-step nucleation pathways in which disordered, amorphous, or dense liquid states precede the appearance of crystalline phases have been reported for a wide range of materials, but the dynamics of such pathways are poorly understood. Moreover, whether these pathways are general features of crystallizing systems or a consequence of system-specific structural details that select for direct versus two-step processes is unknown. Using atomic force microscopy to directly observe crystallization of sequence-defined polymers, we show that crystallization pathways are indeed sequence dependent. When a short hydrophobic region is added to a sequence that directly forms crystalline particles, crystallization instead follows a two-step pathway that begins with the creation of disordered clusters of 10-20 molecules and is characterized by highly non-linear crystallization kinetics in which clusters transform into ordered structures that then enter the growth phase. The results shed new light on non-classical crystallization mechanisms and have implications for the design of self-assembling polymer systems.
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Affiliation(s)
- Xiang Ma
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Shuai Zhang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Fang Jiao
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Christina J Newcomb
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Yuliang Zhang
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Arushi Prakash
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Zhihao Liao
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- Center for Biomaterials and Biopathways, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Marcel D Baer
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Christopher J Mundy
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - James Pfaendtner
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Aleksandr Noy
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- School of Natural Sciences University of California Merced, Merced, California 95343, USA
| | - Chun-Long Chen
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - James J De Yoreo
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
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30
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Li M, Wang L, Putnis CV. Energetic Basis for Inhibition of Calcium Phosphate Biomineralization by Osteopontin. J Phys Chem B 2017; 121:5968-5976. [DOI: 10.1021/acs.jpcb.7b04163] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Meng Li
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Christine V. Putnis
- Institut
für Mineralogie, University of Münster, 48149 Münster, Germany
- Department of Chemistry, Curtin University, Perth, Western Australia 6845, Australia
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31
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Liu C, Zhai H, Zhang Z, Li Y, Xu X, Tang R. Cells Recognize and Prefer Bone-like Hydroxyapatite: Biochemical Understanding of Ultrathin Mineral Platelets in Bone. ACS APPLIED MATERIALS & INTERFACES 2016; 8:29997-30004. [PMID: 27750425 DOI: 10.1021/acsami.6b10374] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hydroxyapatite (HAP) nanocrystallites in all types of bones are distinguished by their ultrathin characteristics, which are uniaxially oriented with fibrillar collagen to uniquely expose the (100) faces. We speculate that living organisms prefer the specific crystal morphology and orientation of HAP because of the interactions between cells and crystals at the mineral-cell interface. Here, bone-like platy HAP (p-HAP) and two different rod-like HAPs were synthesized to investigate the ultrathin mineral modulating effect on cell bioactivity and bone generation. Cell viability and osteogenic differentiation of mesenchymal stem cells (MSCs) were significantly promoted by the platy HAP with (100) faces compared to rod-like HAPs with (001) faces as the dominant crystal orientation, which indicated that MSCs can recognize the crystal face and prefer the (100) HAP faces. This face-specific preference is dependent on the selective adsorption of fibronectin (FN), a plasma protein that plays a central role in cell adhesion, on the HAP surface. This selective adsorption is further confirmed by molecule dynamics (MD) simulation. Our results demonstrate that it is an intelligent choice for cells to use ultrathin HAP with a large (100) face as a basic building block in the hierarchical structure of bone, which is crucial to the promotion of MSCs osteoinductions during bone formation.
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Affiliation(s)
- Cuilian Liu
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
| | - Halei Zhai
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
| | - Zhisen Zhang
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
| | - Yaling Li
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
| | - Xurong Xu
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
| | - Ruikang Tang
- Center for Biomaterials and Biopathways, Department of Chemistry and ‡Qiushi Academy for Advanced Studies, Zhejiang University , Hangzhou, Zhejiang 310027, China
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32
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Abstract
Understanding protein-inorganic surface interactions is central to the rational design of new tools in biomaterial sciences, nanobiotechnology and nanomedicine. Although a significant amount of experimental research on protein adsorption onto solid substrates has been reported, many aspects of the recognition and interaction mechanisms of biomolecules and inorganic surfaces are still unclear. Theoretical modeling and simulations provide complementary approaches for experimental studies, and they have been applied for exploring protein-surface binding mechanisms, the determinants of binding specificity towards different surfaces, as well as the thermodynamics and kinetics of adsorption. Although the general computational approaches employed to study the dynamics of proteins and materials are similar, the models and force-fields (FFs) used for describing the physical properties and interactions of material surfaces and biological molecules differ. In particular, FF and water models designed for use in biomolecular simulations are often not directly transferable to surface simulations and vice versa. The adsorption events span a wide range of time- and length-scales that vary from nanoseconds to days, and from nanometers to micrometers, respectively, rendering the use of multi-scale approaches unavoidable. Further, changes in the atomic structure of material surfaces that can lead to surface reconstruction, and in the structure of proteins that can result in complete denaturation of the adsorbed molecules, can create many intermediate structural and energetic states that complicate sampling. In this review, we address the challenges posed to theoretical and computational methods in achieving accurate descriptions of the physical, chemical and mechanical properties of protein-surface systems. In this context, we discuss the applicability of different modeling and simulation techniques ranging from quantum mechanics through all-atom molecular mechanics to coarse-grained approaches. We examine uses of different sampling methods, as well as free energy calculations. Furthermore, we review computational studies of protein-surface interactions and discuss the successes and limitations of current approaches.
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33
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Zhao W, Xu Z, Cui Q, Sahai N. Predicting the Structure-Activity Relationship of Hydroxyapatite-Binding Peptides by Enhanced-Sampling Molecular Simulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:7009-7022. [PMID: 27329793 DOI: 10.1021/acs.langmuir.6b01582] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding the molecular structural and energetic basis of the interactions between peptides and inorganic surfaces is critical to their applications in tissue engineering and biomimetic material synthesis. Despite recent experimental progresses in the identification and functionalization of hydroxyapatite (HAP)-binding peptides, the molecular mechanisms of their interactions with HAP surfaces are yet to be explored. In particular, the traditional method of molecular dynamics (MD) simulation suffers from insufficient sampling at the peptide-inorganic interface that renders the molecular-level observation dubious. Here we demonstrate that an integrated approach combining bioinformatics, MD, and metadynamics provides a powerful tool for investigating the structure-activity relationship of HAP-binding peptides. Four low charge density peptides, previously identified by phage display, have been considered. As revealed by bioinformatics and MD, the binding conformation of the peptides is controlled by both the sequence and the amino acid composition. It was found that formation of hydrogen bonds between lysine residue and phosphate ions on the surface dictates the binding of positively charged peptide to HAP. The binding affinities of the peptides to the surface are estimated by free energy calculation using parallel-tempering metadynamics, and the results compare favorably to measurements reported in previous experimental studies. The calculation suggests that the charge density of the peptide primarily controls the binding affinity to the surface, while the backbone secondary structure that may restrain side chain orientation toward the surface plays a minor role. We also report that the application of enhanced-sampling metadynamics effects a major advantage over the steered MD method by significantly improving the reliability of binding free energy calculation. In general, our novel integration of diverse sampling techniques should contribute to the rational design of surface-recognition peptides in biomedical applications.
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Affiliation(s)
| | | | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison , Madison, Wisconsin 53706-1322, United States
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34
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Amyloid-like ribbons of amelogenins in enamel mineralization. Sci Rep 2016; 6:23105. [PMID: 27009419 PMCID: PMC4806362 DOI: 10.1038/srep23105] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/29/2016] [Indexed: 12/27/2022] Open
Abstract
Enamel, the outermost layer of teeth, is an acellular mineralized tissue that cannot regenerate; the mature tissue is composed of high aspect ratio apatite nanocrystals organized into rods and inter-rod regions. Amelogenin constitutes 90% of the protein matrix in developing enamel and plays a central role in guiding the hierarchical organization of apatite crystals observed in mature enamel. To date, a convincing link between amelogenin supramolecular structures and mature enamel has yet to be described, in part because the protein matrix is degraded during tissue maturation. Here we show compelling evidence that amelogenin self-assembles into an amyloid-like structure in vitro and in vivo. We show that enamel matrices stain positive for amyloids and we identify a specific region within amelogenin that self-assembles into β-sheets. We propose that amelogenin nanoribbons template the growth of apatite mineral in human enamel. This is a paradigm shift from the current model of enamel development.
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35
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Cannon DA, Ashkenasy N, Tuttle T. Influence of Solvent in Controlling Peptide-Surface Interactions. J Phys Chem Lett 2015; 6:3944-3949. [PMID: 26722896 DOI: 10.1021/acs.jpclett.5b01733] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Protein binding to surfaces is an important phenomenon in biology and in modern technological applications. Extensive experimental and theoretical research has been focused in recent years on revealing the factors that govern binding affinity to surfaces. Theoretical studies mainly focus on examining the contribution of the individual amino acids or, alternatively, the binding potential energies of the full peptide, which are unable to capture entropic contributions and neglect the dynamic nature of the system. We present here a methodology that involves the combination of nonequilibrium dynamics simulations with strategic mutation of polar residues to reveal the different factors governing the binding free energy of a peptide to a surface. Using a gold-binding peptide as an example, we show that relative binding free energies are a consequence of the balance between strong interactions of the peptide with the surface and the ability for the bulk solvent to stabilize the peptide.
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Affiliation(s)
- Daniel A Cannon
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
| | - Nurit Ashkenasy
- Department of Materials Engineering and the Ilze Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev , Beer-Sheva, Israel
| | - Tell Tuttle
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
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36
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Abstract
Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro, and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel.
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Affiliation(s)
- Qichao Ruan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
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37
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Ruan Q, Moradian-Oldak J. Amelogenin and enamel biomimetics. J Mater Chem B 2015. [DOI: 10.1039/c5tb00163c and 21=21] [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
Mature tooth enamel is acellular and does not regenerate itself.
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Affiliation(s)
- Qichao Ruan
- Center for Craniofacial Molecular Biology
- Herman Ostrow School of Dentistry
- University of Southern California
- Los Angeles
- USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology
- Herman Ostrow School of Dentistry
- University of Southern California
- Los Angeles
- USA
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38
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Abstract
The remarkable properties of bone derive from a highly organized arrangement of coaligned nanometer-scale apatite platelets within a fibrillar collagen matrix. The origin of this arrangement is poorly understood and the crystal structures of hydroxyapatite (HAP) and the nonmineralized collagen fibrils alone do not provide an explanation. Moreover, little is known about collagen-apatite interaction energies, which should strongly influence both the molecular-scale organization and the resulting mechanical properties of the composite. We investigated collagen-mineral interactions by combining dynamic force spectroscopy (DFS) measurements of binding energies with molecular dynamics (MD) simulations of binding and atomic force microscopy (AFM) observations of collagen adsorption on single crystals of calcium phosphate for four mineral phases of potential importance in bone formation. In all cases, we observe a strong preferential orientation of collagen binding, but comparison between the observed orientations and transmission electron microscopy (TEM) analyses of native tissues shows that only calcium-deficient apatite (CDAP) provides an interface with collagen that is consistent with both. MD simulations predict preferred collagen orientations that agree with observations, and results from both MD and DFS reveal large values for the binding energy due to multiple binding sites. These findings reconcile apparent contradictions inherent in a hydroxyapatite or carbonated apatite (CAP) model of bone mineral and provide an energetic rationale for the molecular-scale organization of bone.
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39
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Zhao W, Xu Z, Yang Y, Sahai N. Surface energetics of the hydroxyapatite nanocrystal-water interface: a molecular dynamics study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:13283-13292. [PMID: 25314374 DOI: 10.1021/la503158p] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Face-specific interfacial energies and structures of water at ionic crystal surfaces play a dominant role in a wide range of biological, environmental, technological, and industrial processes. Nanosized, plate-shaped crystals of calcium phosphate (CaP) with nonideal stoichiometry of hydroxyapatite (HAP, ideal stoichiometry Ca10(PO4)6(OH)2) comprise the inorganic component of bone and dentin. The crystal shape and size contribute significantly to these tissues' biomechanical properties. Plate-shaped HAP can be grown in the presence of biomolecules, whereas inorganically grown HAP crystals have a needlelike shape. Crystal morphology reflects the relative surface areas of the faces and, for an ideal inorganically grown crystal, should be governed by the surface energies of the faces with water. Interfacial energies and dynamics also affect biomolecule adsorption. Obtaining face-specific surface energies remains experimentally challenging because of the difficulty in growing large HAP single crystals. Here we employed molecular dynamics (MD) simulations to determine nanocrystalline HAP-water interfacial energies. The (100) face was found to be the most favorable energetically, and (110) and (004) were less hydrophilic. The trend in increasing interfacial energy was accompanied by a decrease in the average coordination number of water oxygen to surface calcium ions. The atomic-level geometry of the faces influenced interfacial energy by limiting lateral diffusion of water and by interrupting the hydrogen bond network. Such unfavorable interactions were limited on (100) compared to the other faces. These results provide a thermodynamic basis for the empirically observed trends in relative surface areas of HAP faces. The penetration of charged biomolecules through the interfacial water to form direct interactions with HAP faces, thus potentially influencing morphology, can also be rationalized.
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Affiliation(s)
- Weilong Zhao
- Department of Polymer Science, University of Akron , 170 University Ave., Akron, Ohio 44325-3909, United States
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40
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Parimal S, Cramer SM, Garde S. Application of a Spherical Harmonics Expansion Approach for Calculating Ligand Density Distributions around Proteins. J Phys Chem B 2014; 118:13066-76. [DOI: 10.1021/jp506849k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Siddharth Parimal
- Howard
P. Isermann Department
of Chemical and Biological Engineering and Center for Biotechnology
and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States
| | - Steven M. Cramer
- Howard
P. Isermann Department
of Chemical and Biological Engineering and Center for Biotechnology
and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States
| | - Shekhar Garde
- Howard
P. Isermann Department
of Chemical and Biological Engineering and Center for Biotechnology
and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States
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41
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Tuning calcite morphology and growth acceleration by a rational design of highly stable protein-mimetics. Sci Rep 2014; 4:6266. [PMID: 25189418 PMCID: PMC5385837 DOI: 10.1038/srep06266] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/15/2014] [Indexed: 12/02/2022] Open
Abstract
In nature, proteins play a significant role in biomineral formation. One of the ultimate goals of bioinspired materials science is to develop highly stable synthetic molecules that mimic the function of these natural proteins by controlling crystal formation. Here, we demonstrate that both the morphology and the degree of acceleration or inhibition observed during growth of calcite in the presence of peptoids can be rationally tuned by balancing the electrostatic and hydrophobic interactions, with hydrophobic interactions playing the dominant role. While either strong electrostatic or hydrophobic interactions inhibit growth and reduces expression of the {104} faces, correlations between peptoid-crystal binding energies and observed changes in calcite growth indicate moderate electrostatic interactions allow peptoids to weakly adsorb while moderate hydrophobic interactions cause disruption of surface-adsorbed water layers, leading to growth acceleration with retained expression of the {104} faces. This study provides fundamental principles for designing peptoids as crystallization promoters, and offers a straightforward screening method based on macroscopic crystal morphology. Because peptoids are sequence-specific, highly stable, and easily synthesized, peptoid-enhanced crystallization offers a broad range of potential applications.
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42
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Zhu L, Liu H, Witkowska HE, Huang Y, Tanimoto K, Li W. Preferential and selective degradation and removal of amelogenin adsorbed on hydroxyapatites by MMP20 and KLK4 in vitro. Front Physiol 2014; 5:268. [PMID: 25104939 PMCID: PMC4109566 DOI: 10.3389/fphys.2014.00268] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 06/26/2014] [Indexed: 11/23/2022] Open
Abstract
The hardest tooth enamel tissue develops from a soft layer of protein-rich matrix, predominated by amelogenin that is secreted by epithelial ameloblasts in the secretory stage of tooth enamel development. During enamel formation, a well-controlled progressive removal of matrix proteins by resident proteases, Matrix metalloproteinase 20 (MMP20), and kallikrein 4 (KLK4), will provide space for the apatite crystals to grow. To better understand the role of amelogenin degradation in enamel biomineralization, the present study was conducted to investigate how the adsorption of amelogenin to hydroxyapatite (HAP) crystals affects its degradation by enamel proteinases, MMP20 and KLK4. Equal quantities of amelogenins confirmed by protein assays before digestions, either adsorbed to HAP or in solution, were incubated with MMP20 or KLK4. The digested samples collected at different time points were analyzed by spectrophotometry, SDS-PAGE, high performance liquid chromatography (HPLC), and LC-MALDI MS/MS. We found that majority of amelogenin adsorbed on HAP was released into the surrounding solution by enzymatic processing (88% for MMP20 and 98% for KLK4). The results show that as compared with amelogenin in solution, the HAP-bound amelogenin was hydrolyzed by both MMP20 and KLK4 at significantly higher rates. Using LC-MALDI MS/MS, more accessible cleavage sites and hydrolytic fragments from MMP20/KLK4 digestion were identified for the amelogenin adsorbed on HAP crystals as compared to the amelogenin in solution. These results suggest that the adsorption of amelogenin to HAP results in their preferential and selective degradation and removal from HAP by MMP20 and KLK4 in vitro. Based on these findings, a new degradation model related to enamel crystal growth is proposed.
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Affiliation(s)
- Li Zhu
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco San Francisco, CA, USA
| | - Haichuan Liu
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco San Francisco, CA, USA
| | - H Ewa Witkowska
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco San Francisco, CA, USA
| | - Yulei Huang
- Department of Oral Medicine, Guanghua School of Stomatology, Sun Yat-sen University Guangdong, China
| | - Kataro Tanimoto
- Departments of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences Hiroshima, Japan
| | - Wu Li
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco San Francisco, CA, USA
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43
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Reconciling disparate views of template-directed nucleation through measurement of calcite nucleation kinetics and binding energies. Proc Natl Acad Sci U S A 2014; 111:1304-9. [PMID: 24434555 DOI: 10.1073/pnas.1312369111] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The physical basis for how macromolecules regulate the onset of mineral formation in calcifying tissues is not well established. A popular conceptual model assumes the organic matrix provides a stereochemical match during cooperative organization of solute ions. In contrast, another uses simple binding assays to identify good promoters of nucleation. Here, we reconcile these two views and provide a mechanistic explanation for template-directed nucleation by correlating heterogeneous nucleation barriers with crystal-substrate-binding free energies. We first measure the kinetics of calcite nucleation onto model substrates that present different functional group chemistries (carboxyl, thiol, phosphate, and hydroxyl) and conformations (C11 and C16 chain lengths). We find rates are substrate-specific and obey predictions of classical nucleation theory at supersaturations that extend above the solubility of amorphous calcium carbonate. Analysis of the kinetic data shows the thermodynamic barrier to nucleation is reduced by minimizing the interfacial free energy of the system, γ. We then use dynamic force spectroscopy to independently measure calcite-substrate-binding free energies, ΔGb. Moreover, we show that within the classical theory of nucleation, γ and ΔGb should be linearly related. The results bear out this prediction and demonstrate that low-energy barriers to nucleation correlate with strong crystal-substrate binding. This relationship is general to all functional group chemistries and conformations. These findings provide a physical model that reconciles the long-standing concept of templated nucleation through stereochemical matching with the conventional wisdom that good binders are good nucleators. The alternative perspectives become internally consistent when viewed through the lens of crystal-substrate binding.
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44
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Bleek K, Taubert A. New developments in polymer-controlled, bioinspired calcium phosphate mineralization from aqueous solution. Acta Biomater 2013; 9:6283-321. [PMID: 23291492 DOI: 10.1016/j.actbio.2012.12.027] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/13/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022]
Abstract
The polymer-controlled and bioinspired precipitation of inorganic minerals from aqueous solution at near-ambient or physiological conditions avoiding high temperatures or organic solvents is a key research area in materials science. Polymer-controlled mineralization has been studied as a model for biomineralization and for the synthesis of (bioinspired and biocompatible) hybrid materials for a virtually unlimited number of applications. Calcium phosphate mineralization is of particular interest for bone and dental repair. Numerous studies have therefore addressed the mineralization of calcium phosphate using a wide variety of low- and high-molecular-weight additives. In spite of the growing interest and increasing number of experimental and theoretical data, the mechanisms of polymer-controlled calcium phosphate mineralization are not entirely clear to date, although the field has made significant progress in the last years. A set of elegant experiments and calculations has shed light on some details of mineral formation, but it is currently not possible to preprogram a mineralization reaction to yield a desired product for a specific application. The current article therefore summarizes and discusses the influence of (macro)molecular entities such as polymers, peptides, proteins and gels on biomimetic calcium phosphate mineralization from aqueous solution. It focuses on strategies to tune the kinetics, morphologies, final dimensions and crystal phases of calcium phosphate, as well as on mechanistic considerations.
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Affiliation(s)
- Katrin Bleek
- Institute of Chemistry, University of Potsdam, D-14476 Potsdam, Germany
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45
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Lupulescu AI, Kumar M, Rimer JD. A facile strategy to design zeolite L crystals with tunable morphology and surface architecture. J Am Chem Soc 2013; 135:6608-17. [PMID: 23570284 DOI: 10.1021/ja4015277] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Tailoring the anisotropic growth rates of materials to achieve desired structural outcomes is a pervasive challenge in synthetic crystallization. Here we discuss a method to selectively control the growth of zeolite crystals, which are used extensively in a wide range of industrial applications. This facile method cooperatively tunes crystal properties, such as morphology and surface architecture, through the use of inexpensive, commercially available chemicals with specificity for binding to crystallographic surfaces and mediating anisotropic growth. We examined over 30 molecules as potential zeolite growth modifiers (ZGMs) of zeolite L (LTL type) crystallization. ZGM efficacy was quantified through a combination of macroscopic (bulk) and microscopic (surface) investigations that identified modifiers capable of dramatically altering the cylindrical morphology of LTL crystals. We demonstrate an ability to tailor properties critical to zeolite performance, such as external porous surface area, crystal shape, and pore length, which can enhance sorbate accessibility to LTL pores, tune the supramolecular organization of guest-host composites, and minimize the diffusion path length, respectively. We report that a synergistic combination of ZGMs and the judicious adjustment of synthesis parameters produce LTL crystals with unique surface features, and a range of length-to-diameter aspect ratios spanning 3 orders of magnitude. A systematic examination of different ZGM structures and molecular compositions (i.e., hydrophobicity and binding moieties) reveal interesting physicochemical properties governing their efficacy and specificity. Results of this study suggest this versatile strategy may prove applicable for a host of framework types to produce unrivaled materials that have eluded more conventional techniques.
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Affiliation(s)
- Alexandra I Lupulescu
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204-4004, USA
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46
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Mijajlovic M, Penna MJ, Biggs MJ. Free energy of adsorption for a peptide at a liquid/solid interface via nonequilibrium molecular dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2919-2926. [PMID: 23394469 DOI: 10.1021/la3047966] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Protein adsorption is of wide interest including in many technological applications such as tissue engineering, nanotechnology, biosensors, drug delivery, and vaccine production among others. Understanding the fundamentals of such technologies and their design would be greatly aided by an ability to efficiently predict the conformation of an adsorbed protein and its free energy of adsorption. In the study reported here, we show that this is possible when data obtained from nonequilibrium thermodynamic integration (NETI) combined with steered molecular dynamics (SMD) is subject to bootstrapping. For the met-enkephalin pentapeptide at a water-graphite interface, we were able to obtain accurate predictions for the location of the adsorbed peptide and its free energy of adsorption from around 50 and 80 SMD simulations, respectively. It was also shown that adsorption in this system is both energetically and entropically driven. The free energy of adsorption was also decomposed into that associated with formation of the cavity in the water near the graphite surface sufficient to accommodate the adsorbed peptide and that associated with insertion of the peptide into this cavity. This decomposition reveals that the former is modestly energetically and entropically unfavorable, whereas the latter is the opposite in both regards to a much greater extent.
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Affiliation(s)
- Milan Mijajlovic
- School of Chemical Engineering, The University of Adelaide, Adelaide, South Australia, Australia 5005
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47
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Gungormus M, Oren EE, Horst JA, Fong H, Hnilova M, Somerman MJ, Snead ML, Samudrala R, Tamerler C, Sarikaya M. Cementomimetics-constructing a cementum-like biomineralized microlayer via amelogenin-derived peptides. Int J Oral Sci 2012; 4:69-77. [PMID: 22743342 PMCID: PMC3412665 DOI: 10.1038/ijos.2012.40] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/03/2012] [Indexed: 01/09/2023] Open
Abstract
Cementum is the outer-, mineralized-tissue covering the tooth root and an essential part of the system of periodontal tissue that anchors the tooth to the bone. Periodontal disease results from the destructive behavior of the host elicited by an infectious biofilm adhering to the tooth root and left untreated, may lead to tooth loss. We describe a novel protocol for identifying peptide sequences from native proteins with the potential to repair damaged dental tissues by controlling hydroxyapatite biomineralization. Using amelogenin as a case study and a bioinformatics scoring matrix, we identified regions within amelogenin that are shared with a set of hydroxyapatite-binding peptides (HABPs) previously selected by phage display. One 22-amino acid long peptide regions referred to as amelogenin-derived peptide 5 (ADP5) was shown to facilitate cell-free formation of a cementum-like hydroxyapatite mineral layer on demineralized human root dentin that, in turn, supported attachment of periodontal ligament cells in vitro. Our findings have several implications in peptide-assisted mineral formation that mimic biomineralization. By further elaborating the mechanism for protein control over the biomineral formed, we afford new insights into the evolution of protein-mineral interactions. By exploiting small peptide domains of native proteins, our understanding of structure-function relationships of biomineralizing proteins can be extended and these peptides can be utilized to engineer mineral formation. Finally, the cementomimetic layer formed by ADP5 has the potential clinical application to repair diseased root surfaces so as to promote the regeneration of periodontal tissues and thereby reduce the morbidity associated with tooth loss.
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Affiliation(s)
- Mustafa Gungormus
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
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48
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Wang L, Nilsen-Hamilton M. Biomineralization proteins: from vertebrates to bacteria. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11515-012-1205-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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Chen CL, Bromley KM, Moradian-Oldak J, DeYoreo JJ. In situ AFM study of amelogenin assembly and disassembly dynamics on charged surfaces provides insights on matrix protein self-assembly. J Am Chem Soc 2011; 133:17406-13. [PMID: 21916473 PMCID: PMC3427831 DOI: 10.1021/ja206849c] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Because self-assembly of matrix proteins is a key step in hard tissue mineralization, developing an understanding of the assembly pathways and underlying mechanisms is likely to be important for successful hard tissue engineering. While many studies of matrix protein assembly have been performed on bulk solutions, in vivo these proteins are likely to be in contact with charged biological surfaces composed of lipids, proteins, or minerals. Here we report the results of an in situ atomic force microscopy (AFM) study of self-assembly by amelogenin--the principal protein of the extracellular matrix in developing enamel--in contact with two different charged substrates: hydrophilic negatively charged bare mica and positively charged 3-aminopropyl triethoxysilane (APS) silanized mica. First we demonstrate an AFM-based protocol for determining the size of both amelogenin monomers and oligomers. Using this protocol, we find that, although amelogenin exists primarily as ~26 nm in diameter nanospheres in bulk solution at a pH of 8.0 studied by dynamic light scattering, it behaves dramatically differently upon interacting with charged substrates at the same pH and exhibits complex substrate-dependent assembly pathways and dynamics. On positively charged APS-treated mica surfaces, amelogenin forms a relatively uniform population of decameric oligomers, which then transform into two main populations: higher-order assemblies of oligomers and amelogenin monomers, while on negatively charged bare mica surfaces, it forms a film of monomers that exhibits tip-induced desorption and patterning. The present study represents a successful attempt to identify the size of amelogenin oligomers and to directly monitor assembly and disassembly dynamics on surfaces. The findings have implications for amelogenin-controlled calcium phosphate mineralization in vitro and may offer new insights into in vivo self-assembly of matrix proteins as well as their control over hard tissue formation.
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Affiliation(s)
- Chun-Long Chen
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
| | - Keith M. Bromley
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, United States
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, United States
| | - James J. DeYoreo
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
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