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Mergelsberg ST, Kim H, Buchko GW, Ginovska B. SAXS of murine amelogenin identifies a persistent dimeric species from pH 5.0 to 8.0. J Struct Biol 2024:108131. [PMID: 39368677 DOI: 10.1016/j.jsb.2024.108131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2024]
Abstract
Amelogenin is an intrinsically disordered protein essential to tooth enamel formation in mammals. Using the latest, advanced small angle X-ray scattering (SAXS) capabilities at synchrotrons and computational models, we revisited measuring the quaternary structure of murine amelogenin as a function of pH and phosphorylation at Ser-16. The SAXS data shows that at the pH extremes, amelogenin exists as an extended monomer at pH 3.0 (Rg = 38.4 Å) and nanospheres at pH 8.0 (Rg = 84.0 Å), consistent with multiple previous observations. At pH 5.0 and above there was no evidence for a significant population of monomeric species. Instead, at pH 5.0 ∼ 80% of the population is a heterogenous dimeric species that increases to ∼ 100% at pH 5.5. The dimer population was observed at all pH > 5 conditions in dynamic equilibrium with a species in the pentamer range at pH < 6.5 and nanospheres at pH 8.0. At pH 8.0 ∼ 40% of the amelogenin remained in the dimeric state. In general, serine-16 phosphorylation of amelogenin appears to modestly stabilize the population of the dimeric species.
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Affiliation(s)
| | - Hoshin Kim
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Garry W Buchko
- Pacific Northwest National Laboratory, Richland, WA 99354, USA; School of Molecular Biosciences, Washington State University, Pullman, Washington, USA
| | - Bojana Ginovska
- Pacific Northwest National Laboratory, Richland, WA 99354, USA.
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2
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Kegulian NC, Visakan G, Bapat RA, Moradian-Oldak J. Ameloblastin and its multifunctionality in amelogenesis: A review. Matrix Biol 2024; 131:62-76. [PMID: 38815936 PMCID: PMC11218920 DOI: 10.1016/j.matbio.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/16/2024] [Accepted: 05/24/2024] [Indexed: 06/01/2024]
Abstract
Extracellular matrix proteins play crucial roles in the formation of mineralized tissues like bone and teeth via multifunctional mechanisms. In tooth enamel, ameloblastin (Ambn) is one such multifunctional extracellular matrix protein implicated in cell signaling and polarity, cell adhesion to the developing enamel matrix, and stabilization of prismatic enamel morphology. To provide a perspective for Ambn structure and function, we begin this review by describing dental enamel and enamel formation (amelogenesis) followed by a description of enamel extracellular matrix. We then summarize the established domains and motifs in Ambn protein, human amelogenesis imperfecta cases, and genetically engineered mouse models involving mutated or null Ambn. We subsequently delineate in silico, in vitro, and in vivo evidence for the amphipathic helix in Ambn as a proposed cell-matrix adhesive and then more recent in vitro evidence for the multitargeting domain as the basis for dynamic interactions of Ambn with itself, amelogenin, and membranes. The multitargeting domain facilitates tuning between Ambn-membrane interactions and self/co-assembly and supports a likely overall role for Ambn as a matricellular protein. We anticipate that this review will enhance the understanding of multifunctional matrix proteins by consolidating diverse mechanisms through which Ambn contributes to enamel extracellular matrix mineralization.
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Affiliation(s)
- Natalie C Kegulian
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Gayathri Visakan
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Rucha Arun Bapat
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar St., CSA 148, Los Angeles, CA 90033, USA.
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3
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Øvrebø Ø, De Lauretis A, Ma Q, Lyngstadaas SP, Perale G, Nilsen O, Rossi F, Haugen HJ. Towards bone regeneration: Understanding the nucleating ability of proline-rich peptides in biomineralisation. BIOMATERIALS ADVANCES 2024; 159:213801. [PMID: 38401402 DOI: 10.1016/j.bioadv.2024.213801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/26/2024] [Accepted: 02/18/2024] [Indexed: 02/26/2024]
Abstract
Obtaining rapid mineralisation is a challenge in current bone graft materials, which has been attributed to the difficulty of guiding the biological processes towards osteogenesis. Amelogenin, a key protein in enamel formation, inspired the design of two intrinsically disordered peptides (P2 and P6) that enhance in vivo bone formation, but the process is not fully understood. In this study, we have elucidated the mechanism by which these peptides induce improved mineralisation. Our molecular dynamics analysis demonstrated that in an aqueous environment, P2 and P6 fold to interact with the surrounding Ca2+, PO43- and OH- ions, which can lead to apatite nucleation. Although P2 has a less stable backbone, it folds to a stable structure that allows for the nucleation of larger calcium phosphate aggregates than P6. These results were validated experimentally in a concentrated simulated body fluid solution, where the peptide solutions accelerated the mineralisation process compared to the control and yielded mineral structures mimicking the amorphous calcium phosphate crystals that can be found in lamella bone. A pH drop for the peptide groups suggests depletion of calcium and phosphate, a prerequisite for intrinsic osteoinduction, while S/TEM and SEM suggested that the peptide regulated the mineral nucleation into lamella flakes. Evidently, the peptides accelerate and guide mineral formation, elucidating the mechanism for how these peptides can improve the efficacy of P2 or P6 containing devices for bone regeneration. The work also demonstrates how experimental mineralisation study coupled with molecular dynamics is a valid method for understanding and predicting in vivo performance prior to animal trials.
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Affiliation(s)
- Øystein Øvrebø
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway; Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy; Material Biomimetic AS, Oslo Science Park, 0349 Oslo, Norway
| | - Angela De Lauretis
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway; Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy
| | - Qianli Ma
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway
| | - Ståle Petter Lyngstadaas
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway
| | - Giuseppe Perale
- Industrie Biomediche Insubri SA, Mezzovico-Vira 6805, Switzerland; Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano 6900, Switzerland; Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Ola Nilsen
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Gaustadalléen 21, NO-0349 Oslo, Norway
| | - Filippo Rossi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, 20133 Milano, Italy
| | - Håvard J Haugen
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, 0318 Oslo, Norway.
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4
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Hu D, Ren Q, Li Z, Han S, Ding L, Lu Z, Zhang L. Unveiling the mechanism of an amelogenin-derived peptide in promoting enamel biomimetic remineralization. Int J Biol Macromol 2023; 253:127322. [PMID: 37848117 DOI: 10.1016/j.ijbiomac.2023.127322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/19/2023]
Abstract
Amelogenin and its derived peptides have exhibited excellent efficacy in promoting enamel biomimetic remineralization. However, little is known about their specific action mechanisms. Herein, by combining experiments and computer simulation, the mechanism of an amelogenin-derived peptide QP5 in regulating enamel biomimetic remineralization is unveiled for the first time. In experiments, peptide QP5 was separated into (QPX)5 and C-tail domains, the interactions of peptide-minerals in nucleation solution and the regulation of peptide on enamel biomimetic remineralization were explored. QP5 exhibited an unordered conformation when mineral ions existed, and it could adsorb on minerals through its two domains, thereby inhibiting spontaneous nucleation. The remineralized enamel regulated by C-tail showed better mechanical properties and formed more biomimetic crystals than that of (QPX)5, indicating the C-tail domain of QP5 played an important role in forming enamel-like crystals. The simulation results showed that the conformation of QP5 changed greatly, mainly exhibiting β-bend, β-turn, and coil structures, and it eventually adsorbed on enamel through negatively charged residues of the C-tail domain, then captured Ca2+ from solution to promote enamel remineralization. This study improved the evaluation methods of the mechanism of biomimetic peptides, and laid a theoretical basis for the amelioration and clinical transformation of peptide QP5.
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Affiliation(s)
- Die Hu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Qian Ren
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Zhongcheng Li
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Sili Han
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Longjiang Ding
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Ziqian Lu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China
| | - Linglin Zhang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China; Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, No.14, Section 3, Renmin Road South, Chengdu 610041, China.
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5
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Lasota A, Kuczumow A, Gorzelak M, Blicharski T, Niezbecka-Zając J, Turżańska K, Szabelska A, Łobacz M, Wiszumirska K, Wieruszewski M, Jarzębski M, Jabłoński M. Contribution to Knowledge on Bioapatites: Does Mg Level Reflect the Organic Matter and Water Contents of Enamel? Int J Mol Sci 2023; 24:15974. [PMID: 37958956 PMCID: PMC10648067 DOI: 10.3390/ijms242115974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/26/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
The matter constituting the enamels of four types of organisms was studied. The variability of the ions was presented in molar units. It was proven that the changes in water contents of the enamel are significantly positively related to changes in Mg; inversely, there is also a strong connection with changes in Ca and P, the main components of bioapatite. The variability in the organic matter has the same strong and positive characteristics and is also coupled with changes in Mg contents. Amelogenins in organic matter, which synthesize enamel rods, likely have a role in adjusting the amount of Mg, thus establishing the amount of organic matter and water in the whole enamel; this adjustment occurs through an unknown mechanism. Ca, P, Mg, and Cl ions, as well as organic matter and water, participate in the main circulation cycle of bioapatites. The selection of variations in the composition of bioapatite occurs only along particular trajectories, where the energy of transformation linearly depends on the following factors: changes in the crystallographic d parameter; the increase in the volume, V, of the crystallographic cell; the momentum transfer, which is indirectly expressed by ΔsinΘ value. To our knowledge, these findings are novel in the literature. The obtained results indicate the different chemical and crystallographic affinities of the enamels of selected animals to the human ones. This is essential when animal bioapatites are transformed into dentistic or medical substitutes for the hard tissues. Moreover, the role of Mg is shown to control the amount of water in the apatite and in detecting organic matter in the enamels.
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Affiliation(s)
- Agnieszka Lasota
- Department of Maxillary Orthopaedics, Medical University of Lublin, Chodźki 6, 20-093 Lublin, Poland;
| | | | - Mieczysław Gorzelak
- Clinic of Rehabilitation and Orthopedics, Medical University of Lublin, 20-090 Lublin, Poland; (M.G.); (T.B.); (J.N.-Z.); (K.T.); (M.J.)
| | - Tomasz Blicharski
- Clinic of Rehabilitation and Orthopedics, Medical University of Lublin, 20-090 Lublin, Poland; (M.G.); (T.B.); (J.N.-Z.); (K.T.); (M.J.)
| | - Joanna Niezbecka-Zając
- Clinic of Rehabilitation and Orthopedics, Medical University of Lublin, 20-090 Lublin, Poland; (M.G.); (T.B.); (J.N.-Z.); (K.T.); (M.J.)
| | - Karolina Turżańska
- Clinic of Rehabilitation and Orthopedics, Medical University of Lublin, 20-090 Lublin, Poland; (M.G.); (T.B.); (J.N.-Z.); (K.T.); (M.J.)
| | - Anna Szabelska
- Department of Dental Techniques with the Lab of Modern Technologies, Medical University of Lublin, Chodźki 6, 20-093 Lublin, Poland;
| | - Michał Łobacz
- Chair and Department of Oral Surgery, Medical University of Lublin, Chodźki 6, 20-093 Lublin, Poland;
| | - Karolina Wiszumirska
- Institute of Quality Science, Department of Industrial Products and Packaging Quality, Poznan University of Economics and Business, Al. Niepodległosci 10, 61-875 Poznan, Poland;
| | - Marek Wieruszewski
- Department Mechanical Wood Technology, Faculty of Forestry and Wood Technology, Poznan University of Life Sciences, Wojska Polskiego 28, 60-637 Poznan, Poland;
| | - Maciej Jarzębski
- Department of Physics and Biophysics, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-637 Poznan, Poland
| | - Mirosław Jabłoński
- Clinic of Rehabilitation and Orthopedics, Medical University of Lublin, 20-090 Lublin, Poland; (M.G.); (T.B.); (J.N.-Z.); (K.T.); (M.J.)
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6
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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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7
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Shao C, Bapat RA, Su J, Moradian-Oldak J. Regulation of Hydroxyapatite Nucleation In Vitro through Ameloblastin-Amelogenin Interactions. ACS Biomater Sci Eng 2023; 9:1834-1842. [PMID: 35068157 PMCID: PMC9308824 DOI: 10.1021/acsbiomaterials.1c01113] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Amelogenin (Amel) and ameloblastin (Ambn) are two primary extracellular enamel matrix proteins that play crucial roles for proper thickness, prismatic structure, and robust mechanical properties. Previous studies have shown that Amel and Ambn bind to each other, but the effect of their coassembly on the nucleation of hydroxyapatite (HAP) is unclear. Here, we systematically investigated the coassembly of recombinant mouse Amel and Ambn in various ratios using in situ atomic force microscopy, dynamic light scattering, and transmission electron microscopy. The size of protein particles decreased as the Ambn:Amel ratio increased. To define the coassembly domain on Ambn, we used Ambn-derived peptides and Ambn variants to examine their effects on the amelogenin particle size distribution. We found that the peptide sequence encoded by exon 5 of Ambn affected Amel self-assembly but the variant lacking this sequence did not have any effect on Amel self-assembly. Furthermore, through monitoring the pH change in bulk mineralization solution, we tracked the nucleation behavior of HAP in the presence of Ambn and Amel and found that their coassemblies at different ratios showed varying abilities to stabilize amorphous calcium phosphate. These results demonstrated that Ambn and Amel coassemble with each other via a motif within the sequence encoded by exon 5 of Ambn and cooperate in regulating the nucleation of HAP crystals, enhancing our understanding of the important role of enamel matrix proteins in amelogenesis.
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Affiliation(s)
- Changyu Shao
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Rucha Arun Bapat
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Jingtan Su
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, California 90033, United States
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Chan B, Cheng IC, Rozita J, Gorshteyn I, Huang Y, Shaffer I, Chang C, Li W, Lytton J, Den Besten P, Zhang Y. Sodium/(calcium + potassium) exchanger NCKX4 optimizes KLK4 activity in the enamel matrix microenvironment to regulate ECM modeling. Front Physiol 2023; 14:1116091. [PMID: 36814474 PMCID: PMC9939835 DOI: 10.3389/fphys.2023.1116091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
Enamel development is a process in which extracellular matrix models from a soft proteinaceous matrix to the most mineralized tissue in vertebrates. Patients with mutant NCKX4, a gene encoding a K+-dependent Na+/Ca2+-exchanger, develop a hypomineralized and hypomature enamel. How NCKX4 regulates enamel protein removal to achieve an almost protein-free enamel is unknown. We characterized the upregulation pattern of Nckx4 in the progressively differentiating enamel-forming ameloblasts by qPCR, and as well as confirmed NCKX4 protein to primarily localize at the apical surface of wild-type ruffle-ended maturation ameloblasts by immunostaining of the continuously growing mouse incisors, posing the entire developmental trajectory of enamel. In contrast to the normal mature enamel, where ECM proteins are hydrolyzed and removed, we found significant protein retention in the maturation stage of Nckx4 -/- mouse enamel. The Nckx4 -/- enamel held less Ca2+ and K+ but more Na+ than the Nckx4 +/+ enamel did, as measured by EDX. The alternating acidic and neutral pH zones at the surface of mineralizing Nckx4 +/+ enamel were replaced by a largely neutral pH matrix in the Nckx4 -/- enamel. In situ zymography revealed a reduced kallikrein-related peptidase 4 (KLK4) activity in the Nckx4 -/- enamel. We showed that KLK4 took on 90% of proteinase activity in the maturation stage of normal enamel, and that recombinant KLK4 as well as native mouse enamel KLK4 both performed less effectively in a buffer with increased [Na+] and pH, conditions found in the Nckx4 -/- developing enamel. This study, for the first time to our knowledge, provides evidence demonstrating the impaired in situ KLK4 activity in Nckx4 -/- enamel and suggests a novel function of NCKX4 in facilitating KLK4-mediated hydrolysis and removal of ECM proteins, warranting the completion of enamel matrix modeling.
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Affiliation(s)
- Barry Chan
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ieong Cheng Cheng
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jalali Rozita
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ida Gorshteyn
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yulei Huang
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Ida Shaffer
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Chih Chang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Wu Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jonathan Lytton
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Pamela Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
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9
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Buchko GW, Zhou M, Vesely CH, Tao J, Shaw WJ, Mehl RA, Cooley RB. High-yield recombinant bacterial expression of 13 C-, 15 N-labeled, serine-16 phosphorylated, murine amelogenin using a modified third generation genetic code expansion protocol. Protein Sci 2023; 32:e4560. [PMID: 36585836 PMCID: PMC9850436 DOI: 10.1002/pro.4560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/21/2022] [Accepted: 12/29/2022] [Indexed: 01/01/2023]
Abstract
Amelogenin constitutes ~90% of the enamel matrix in the secretory stage of amelogenesis, a still poorly understood process that results in the formation of the hardest and most mineralized tissue in vertebrates-enamel. Most biophysical research with amelogenin uses recombinant protein expressed in Escherichia coli. In addition to providing copious amounts of protein, recombinant expression allows 13 C- and 15 N-labeling for detailed structural studies using NMR spectroscopy. However, native amelogenin is phosphorylated at one position, Ser-16 in murine amelogenin, and there is mounting evidence that Ser-16 phosphorylation is important. Using a modified genetic code expansion protocol we have expressed and purified uniformly 13 C-, 15 N-labeled murine amelogenin (pS16M179) with ~95% of the protein being correctly phosphorylated. Homogeneous phosphorylation was achieved using commercially available, enriched, 13 C-, 15 N-labeled media, and protein expression was induced with isopropyl β-D-1-thiogalactopyranoside at 310 K. Phosphoserine incorporation was verified from one-dimensional 31 P NMR spectra, comparison of 1 H-15 N HSQC spectra, Phos-tag SDS PAGE, and mass spectrometry. Phosphorus-31 NMR spectra for pS16M179 under conditions known to trigger amelogenin self-assembly into nanospheres confirm nanosphere models with buried N-termini. Lambda phosphatase treatment of these nanospheres results in the dephosphorylation of pS16M179, confirming that smaller oligomers and monomers with exposed N-termini are in equilibrium with nanospheres. Such 13 C-, 15 N-labeling of amelogenin with accurately encoded phosphoserine incorporation will accelerate biomineralization research to understand amelogenesis and stimulate the expanded use of genetic code expansion protocols to introduce phosphorylated amino acids into proteins.
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Affiliation(s)
- Garry W. Buchko
- Earth and Biological Sciences DirectoratePacific Northwest National LaboratoryRichlandWashingtonUSA,School of Molecular BiosciencesWashington State UniversityPullmanWashingtonUSA
| | - Mowei Zhou
- Earth and Biological Sciences DirectoratePacific Northwest National LaboratoryRichlandWashingtonUSA
| | - Cat Hoang Vesely
- Department of Biochemistry and BiophysicsOregon State UniversityCorvallisOregonUSA
| | - Jinhui Tao
- Physical and Computational Sciences DirectoratePacific Northwest National LaboratoryRichlandWashingtonUSA
| | - Wendy J. Shaw
- Physical and Computational Sciences DirectoratePacific Northwest National LaboratoryRichlandWashingtonUSA
| | - Ryan A. Mehl
- Department of Biochemistry and BiophysicsOregon State UniversityCorvallisOregonUSA
| | - Richard B. Cooley
- Department of Biochemistry and BiophysicsOregon State UniversityCorvallisOregonUSA
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10
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Proline-rich protein from S. mutans can perform a competitive mineralization function to enhance bacterial adhesion to teeth. Sci Rep 2022; 12:22250. [PMID: 36564474 PMCID: PMC9789152 DOI: 10.1038/s41598-022-26303-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022] Open
Abstract
A proline-rich region was found in Streptococcus mutans (S. mutans) surface antigen I/II (Ag I/II). The functions of this region were explored to determine its role in the cariogenic abilities of S. mutans; specifically, the proline-rich region was compared with human amelogenin. The full-length amelogenin genes were cloned from human (AmH) and surface antigen I/II genes from S. mutans. Then, the genes expressed and purified. We analyzed the structure and self-assembly ability of AmH and Ag I/II, compared their capacities to induce mineralization, and assessed the adhesion ability of S. mutans to AmH- and Ag I/II-coated tooth slices. AmH formed ordered chains and net frames in the early stage of protein self-assembly, while Ag I/II formed irregular and overlapping structures. AmH induced mineralization possessed a parallel rosary structure, while Ag I/II-induced mineralization is rougher and more irregular. The S. mutans adhesion assay indicated that the adhesion ability S. mutans on the Ag I/II-induced crystal layer was significantly higher than that on the AmH-induced crystal layer. S. mutans' Ag I/II may have evolved to resemble human amelogenin and form a rougher crystal layer on teeth, which play a competitive mineralization role and promotes better bacterial adhesion and colonization. Thus, the cariogenic ability of S. mutans Ag I/II is increased.
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11
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Zhang Y, Jin T, Zhu W, Pandya M, Gopinathan G, Allen M, Reed D, Keiderling T, Liao X, Diekwisch TGH. Highly acidic pH facilitates enamel protein self-assembly, apatite crystal growth and enamel protein interactions in the early enamel matrix. Front Physiol 2022; 13:1019364. [PMID: 36569763 PMCID: PMC9772882 DOI: 10.3389/fphys.2022.1019364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Tooth enamel develops within a pH sensitive amelogenin-rich protein matrix. The purpose of the present study is to shed light on the intimate relationship between enamel matrix pH, enamel protein self-assembly, and enamel crystal growth during early amelogenesis. Universal indicator dye staining revealed highly acidic pH values (pH 3-4) at the exocytosis site of secretory ameloblasts. When increasing the pH of an amelogenin solution from pH 5 to pH 7, there was a gradual increase in subunit compartment size from 2 nm diameter subunits at pH 5 to a stretched configuration at pH6 and to 20 nm subunits at pH 7. HSQC NMR spectra revealed that the formation of the insoluble amelogenin self-assembly structure at pH6 was critically mediated by at least seven of the 11 histidine residues of the amelogenin coil domain (AA 46-117). Comparing calcium crystal growth on polystyrene plates, crystal length was more than 20-fold elevated at pH 4 when compared to crystals grown at pH 6 or pH 7. To illustrate the effect of pH on enamel protein self-assembly at the site of initial enamel formation, molar teeth were immersed in phosphate buffer at pH4 and pH7, resulting in the formation of intricate berry tree-like assemblies surrounding initial enamel crystal assemblies at pH4 that were not evident at pH7 nor in citrate buffer. Amelogenin and ameloblastin enamel proteins interacted at the secretory ameloblast pole and in the initial enamel layer, and co-immunoprecipitation studies revealed that this amelogenin/ameloblastin interaction preferentially takes place at pH 4-pH 4.5. Together, these studies highlight the highly acidic pH of the very early enamel matrix as an essential contributing factor for enamel protein structure and self-assembly, apatite crystal growth, and enamel protein interactions.
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Affiliation(s)
- Youbin Zhang
- Department of Oral Biology, University of Illinois at Chicago, Dallas, Illinois, United States
| | - Tianquan Jin
- Department of Oral Biology, University of Illinois at Chicago, Dallas, Illinois, United States
| | - Weiying Zhu
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Mirali Pandya
- Center for Craniofacial Research and Diagnosis, Texas A and M College of Dentistry, Dallas, Texas, United States
| | - Gokul Gopinathan
- Center for Craniofacial Research and Diagnosis, Texas A and M College of Dentistry, Dallas, Texas, United States
| | - Michael Allen
- Department of Medicine, University of Chicago, Chicago, Illinois, United States
| | - David Reed
- Department of Oral Biology, University of Illinois at Chicago, Dallas, Illinois, United States
| | - Timothy Keiderling
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, United States,*Correspondence: Timothy Keiderling, ; Xiubei Liao, ; Thomas G. H. Diekwisch,
| | - Xiubei Liao
- Department of Biochemistry, University of Illinois at Chicago, Chicago, Illinois, United States,*Correspondence: Timothy Keiderling, ; Xiubei Liao, ; Thomas G. H. Diekwisch,
| | - Thomas G. H. Diekwisch
- Department of Oral Biology, University of Illinois at Chicago, Dallas, Illinois, United States,Center for Craniofacial Research and Diagnosis, Texas A and M College of Dentistry, Dallas, Texas, United States,*Correspondence: Timothy Keiderling, ; Xiubei Liao, ; Thomas G. H. Diekwisch,
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12
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Buchko GW, Mergelsberg ST, Tarasevich BJ, Shaw WJ. Residue-Specific Insights into the Intermolecular Protein–Protein Interfaces Driving Amelogenin Self-Assembly in Solution. Biochemistry 2022; 61:2909-2921. [DOI: 10.1021/acs.biochem.2c00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- Garry W. Buchko
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
- School of Molecular Biosciences, Washington State University, Pullman, Washington 99164, United States
| | - Sebastian T. Mergelsberg
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Barbara J. Tarasevich
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Wendy J. Shaw
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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13
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Zhang X, Wu L, Feng G, Lei S. Mineralization of calcium phosphate on two-dimensional polymer films with controllable density of carboxyl groups. J Mater Chem B 2022; 10:3793-3797. [PMID: 35485398 DOI: 10.1039/d2tb00195k] [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
Two-dimensional polymers functionalized with controllable density of carboxyl groups were constructed with the Langmuir-Blodgett method. Mineralization of calcium phosphate shows significantly different characteristics on these films, which clearly indicates that the density of carboxy groups plays a determining role in controlling the nucleation and orientated growth of calcium phosphate.
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Affiliation(s)
- Xinyu Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
| | - Lingli Wu
- Medical College, Northwest Minzu University, Lanzhou 730000, China.
| | - Guangyuan Feng
- Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
| | - Shengbin Lei
- Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
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14
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Loss of biological control of enamel mineralization in amelogenin-phosphorylation-deficient mice. J Struct Biol 2022; 214:107844. [DOI: 10.1016/j.jsb.2022.107844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/23/2022]
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15
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Tang S, Dong Z, Ke X, Luo J, Li J. Advances in biomineralization-inspired materials for hard tissue repair. Int J Oral Sci 2021; 13:42. [PMID: 34876550 PMCID: PMC8651686 DOI: 10.1038/s41368-021-00147-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 12/24/2022] Open
Abstract
Biomineralization is the process by which organisms form mineralized tissues with hierarchical structures and excellent properties, including the bones and teeth in vertebrates. The underlying mechanisms and pathways of biomineralization provide inspiration for designing and constructing materials to repair hard tissues. In particular, the formation processes of minerals can be partly replicated by utilizing bioinspired artificial materials to mimic the functions of biomolecules or stabilize intermediate mineral phases involved in biomineralization. Here, we review recent advances in biomineralization-inspired materials developed for hard tissue repair. Biomineralization-inspired materials are categorized into different types based on their specific applications, which include bone repair, dentin remineralization, and enamel remineralization. Finally, the advantages and limitations of these materials are summarized, and several perspectives on future directions are discussed.
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Affiliation(s)
- Shuxian Tang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Zhiyun Dong
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Xiang Ke
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China
| | - Jun Luo
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China.
| | - Jianshu Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, PR China.
- Med-X Center for Materials, Sichuan University, Chengdu, PR China.
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16
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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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17
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Song J. Adenosine triphosphate energy-independently controls protein homeostasis with unique structure and diverse mechanisms. Protein Sci 2021; 30:1277-1293. [PMID: 33829608 PMCID: PMC8197423 DOI: 10.1002/pro.4079] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Proteins function in the crowded cellular environments with high salt concentrations, thus facing tremendous challenges of misfolding/aggregation which represents a pathological hallmark of aging and an increasing spectrum of human diseases. Recently, intrinsically disordered regions (IDRs) were recognized to drive liquid-liquid phase separation (LLPS), a common principle for organizing cellular membraneless organelles (MLOs). ATP, the universal energy currency for all living cells, mysteriously has concentrations of 2-12 mM, much higher than required for its previously-known functions. Only recently, ATP was decoded to behave as a biological hydrotrope to inhibit protein LLPS and aggregation at mM. We further revealed that ATP also acts as a bivalent binder, which not only biphasically modulates LLPS driven by IDRs of human and viral proteins, but also bind to the conserved nucleic-acid-binding surfaces of the folded proteins. Most unexpectedly, ATP appears to act as a hydration mediator to antagonize the crowding-induced destabilization as well as to enhance folding of proteins without significant binding. Here, this review focuses on summarizing the results of these biophysical studies and discussing their implications in an evolutionary context. By linking triphosphate with unique hydration property to adenosine, ATP appears to couple the ability for establishing hydrophobic, π-π, π-cation and electrostatic interactions to the capacity in mediating hydration of proteins, which is at the heart of folding, dynamics, stability, phase separation and aggregation. Consequently, ATP acquired a category of functions at ~mM to energy-independently control protein homeostasis with diverse mechanisms, thus implying a link between cellular ATP concentrations and protein-aggregation diseases.
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Affiliation(s)
- Jianxing Song
- Department of Biological Sciences, Faculty of ScienceNational University of SingaporeSingaporeSingapore
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18
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Sharma V, Srinivasan A, Nikolajeff F, Kumar S. Biomineralization process in hard tissues: The interaction complexity within protein and inorganic counterparts. Acta Biomater 2021; 120:20-37. [PMID: 32413577 DOI: 10.1016/j.actbio.2020.04.049] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/17/2020] [Accepted: 04/26/2020] [Indexed: 02/07/2023]
Abstract
Biomineralization can be considered as nature's strategy to produce and sustain biominerals, primarily via creation of hard tissues for protection and support. This review examines the biomineralization process within the hard tissues of the human body with special emphasis on the mechanisms and principles of bone and teeth mineralization. We describe the detailed role of proteins and inorganic ions in mediating the mineralization process. Furthermore, we highlight the various available models for studying bone physiology and mineralization starting from the historical static cell line-based methods to the most advanced 3D culture systems, elucidating the pros and cons of each one of these methods. With respect to the mineralization process in teeth, enamel and dentin mineralization is discussed in detail. The key role of intrinsically disordered proteins in modulating the process of mineralization in enamel and dentine is given attention. Finally, nanotechnological interventions in the area of bone and teeth mineralization, diseases and tissue regeneration is also discussed. STATEMENT OF SIGNIFICANCE: This article provides an overview of the biomineralization process within hard tissues of the human body, which encompasses the detailed mechanism innvolved in the formation of structures like teeth and bone. Moreover, we have discussed various available models used for studying biomineralization and also explored the nanotechnological applications in the field of bone regeneration and dentistry.
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Affiliation(s)
- Vaibhav Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
| | | | | | - Saroj Kumar
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
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19
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Shaw WJ, Tarasevich BJ, Buchko GW, Arachchige RMJ, Burton SD. Controls of nature: Secondary, tertiary, and quaternary structure of the enamel protein amelogenin in solution and on hydroxyapatite. J Struct Biol 2020; 212:107630. [PMID: 32979496 PMCID: PMC7744360 DOI: 10.1016/j.jsb.2020.107630] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/12/2020] [Accepted: 09/17/2020] [Indexed: 10/23/2022]
Abstract
Amelogenin, a protein critical to enamel formation, is presented as a model for understanding how the structure of biomineralization proteins orchestrate biomineral formation. Amelogenin is the predominant biomineralization protein in the early stages of enamel formation and contributes to the controlled formation of hydroxyapatite (HAP) enamel crystals. The resulting enamel mineral is one of the hardest tissues in the human body and one of the hardest biominerals in nature. Structural studies have been hindered by the lack of techniques to evaluate surface adsorbed proteins and by amelogenin's disposition to self-assemble. Recent advancements in solution and solid state nuclear magnetic resonance (NMR) spectroscopy, atomic force microscopy (AFM), and recombinant isotope labeling strategies are now enabling detailed structural studies. These recent studies, coupled with insights from techniques such as CD and IR spectroscopy and computational methodologies, are contributing to important advancements in our structural understanding of amelogenesis. In this review we focus on recent advances in solution and solid state NMR spectroscopy and in situ AFM that reveal new insights into the secondary, tertiary, and quaternary structure of amelogenin by itself and in contact with HAP. These studies have increased our understanding of the interface between amelogenin and HAP and how amelogenin controls enamel formation.
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Affiliation(s)
- Wendy J Shaw
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
| | - Barbara J Tarasevich
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Garry W Buchko
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA; School of Molecular Bioscience, Washington State University, Pullman, WA 99164, USA
| | - Rajith M J Arachchige
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Sarah D Burton
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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20
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Dissanayake SSM, Ekambaram M, Li KC, Harris PWR, Brimble MA. Identification of Key Functional Motifs of Native Amelogenin Protein for Dental Enamel Remineralisation. MOLECULES (BASEL, SWITZERLAND) 2020; 25:molecules25184214. [PMID: 32937944 PMCID: PMC7571260 DOI: 10.3390/molecules25184214] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 02/04/2023]
Abstract
Dental caries or tooth decay is a preventable and multifactorial disease that affects billions of people globally and is a particular concern in younger populations. This decay arises from acid demineralisation of tooth enamel resulting in mineral loss from the subsurface. The remineralisation of early enamel carious lesions could prevent the cavitation of teeth. The enamel protein amelogenin constitutes 90% of the total enamel matrix protein in teeth and plays a key role in the biomineralisation of tooth enamel. The physiological importance of amelogenin has led to the investigation of the possible development of amelogenin-derived biomimetics against dental caries. We herein review the literature on amelogenin, its primary and secondary structure, comparison to related species, and its’ in vivo processing to bioactive peptide fragments. The key structural motifs of amelogenin that enable enamel remineralisation are discussed. The presence of several motifs in the amelogenin structure (such as polyproline, N- and C-terminal domains and C-terminal orientation) were shown to play a critical role in the formation of particle shape during remineralization. Understanding the function/structure relationships of amelogenin can aid in the rational design of synthetic polypeptides for biomineralisation, halting enamel loss and leading to improved therapies for tooth decay.
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Affiliation(s)
- Shama S. M. Dissanayake
- School of Chemical Sciences, 23 Symonds St, The University of Auckland, Auckland 1142, New Zealand;
| | - Manikandan Ekambaram
- Paediatric Dentistry, Biomaterials, Faculty of Dentistry, The University of Otago, Dunedin 9016, New Zealand; (M.E.); (K.C.L.)
| | - Kai Chun Li
- Paediatric Dentistry, Biomaterials, Faculty of Dentistry, The University of Otago, Dunedin 9016, New Zealand; (M.E.); (K.C.L.)
| | - Paul W. R. Harris
- School of Chemical Sciences, 23 Symonds St, The University of Auckland, Auckland 1142, New Zealand;
- School of Biological Sciences, 3b Symonds St, The University of Auckland, Auckland 1142, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, 3b Symonds St, The University of Auckland, Auckland 1142, New Zealand
- Correspondence: (P.W.R.H.); (M.A.B.); Tel.: +64-9-373-7599 (P.W.R.H. & M.A.B.); Fax: +64-9-373-7422 (P.W.R.H. & M.A.B.)
| | - Margaret A. Brimble
- School of Chemical Sciences, 23 Symonds St, The University of Auckland, Auckland 1142, New Zealand;
- School of Biological Sciences, 3b Symonds St, The University of Auckland, Auckland 1142, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, 3b Symonds St, The University of Auckland, Auckland 1142, New Zealand
- Correspondence: (P.W.R.H.); (M.A.B.); Tel.: +64-9-373-7599 (P.W.R.H. & M.A.B.); Fax: +64-9-373-7422 (P.W.R.H. & M.A.B.)
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21
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22
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Zhu H, Gomez M, Xiao J, Perale G, Betge F, Lyngstadaas SP, Haugen HJ. Xenohybrid Bone Graft Containing Intrinsically Disordered Proteins Shows Enhanced In Vitro Bone Formation. ACS APPLIED BIO MATERIALS 2020; 3:2263-2274. [DOI: 10.1021/acsabm.0c00064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hao Zhu
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, 430030 Wuhan, China
- Corticalis AS, Oslo Sciencepark, Gaustadallén 21, NO-0349 Oslo, Norway
| | - Manuel Gomez
- Corticalis AS, Oslo Sciencepark, Gaustadallén 21, NO-0349 Oslo, Norway
| | - Jun Xiao
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, 430030 Wuhan, China
| | - Giuseppe Perale
- Industrie Biomediche Insubri SA, Via Cantonale 67, 6805 Mezzovico-Vira, Switzerland
- Faculty of Biomedical Sciences, University of Southern Switzerland, Via G. Buffi 13, 6900 Lugano, Switzerland
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Donaueschingenstrasse 13, 1200 Vienna, Austria
| | - Felice Betge
- Industrie Biomediche Insubri SA, Via Cantonale 67, 6805 Mezzovico-Vira, Switzerland
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The Evolution of Unusually Small Amelogenin Genes in Cetaceans; Pseudogenization, X-Y Gene Conversion, and Feeding Strategy. J Mol Evol 2019; 88:122-135. [PMID: 31754761 DOI: 10.1007/s00239-019-09917-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 11/08/2019] [Indexed: 12/11/2022]
Abstract
Among extant cetaceans, mysticetes are filter feeders that do not possess teeth and use their baleen for feeding, while most odontocetes are considered suction feeders, which capture prey by suction without biting or chewing with teeth. In the present study, we address the functionality of amelogenin (AMEL) genes in cetaceans. AMEL encodes a protein that is specifically involved in dental enamel formation and is located on the sex chromosomes in eutherians. The X-copy AMELX is functional in enamel-bearing eutherians, whereas the Y-copy AMELY appears to have undergone decay and was completely lost in some species. Consistent with these premises, we detected various deleterious mutations and/or non-canonical splice junctions in AMELX of mysticetes and four suction feeding odontocetes, Delphinapterus leucas, Monodon monoceros, Kogia breviceps, and Physeter macrocephalus, and in AMELY of mysticetes and odontocetes. Regardless of the functionality, both AMELX and AMELY are equally and unusually small in cetaceans, and even their functional AMELX genes presumably encode a degenerate core region, which is thought to be essential for enamel matrix assembly and enamel crystal growth. Furthermore, our results suggest that the most recent common ancestors of extant cetaceans had functional AMELX and AMELY, both of which are similar to AMELX of Platanista minor. Similar small AMELX and AMELY in archaic cetaceans can be explained by gene conversion between AMELX and AMELY. We speculate that common ancestors of modern cetaceans employed a degenerate AMELX, transferred from a decaying AMELY by gene conversion, at an early stage of their transition to suction feeders.
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24
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Wisdom EC, Zhou Y, Chen C, Tamerler C, Snead ML. Mitigation of peri-implantitis by rational design of bifunctional peptides with antimicrobial properties. ACS Biomater Sci Eng 2019; 6:2682-2695. [PMID: 32467858 DOI: 10.1021/acsbiomaterials.9b01213] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The integration of molecular and cell biology with materials science has led to strategies to improve the interface between dental implants with the surrounding soft and hard tissues in order to replace missing teeth and restore mastication. More than 3 million implants have been placed in the US alone and this number is rising by 500,000/year. Peri-implantitis, an inflammatory response to oral pathogens growing on the implant surface threatens to reduce service life leading to eventual implant failure, and such an outcome will have adverse impact on public health and create significant health care costs. Here we report a predictive approach to peptide design, which enabled us to engineer a bifunctional peptide to combat bacterial colonization and biofilm formation, reducing the adverse host inflammatory immune response that destroys the tissue surrounding implants and shortens their lifespans. This bifunctional peptide contains a titanium-binding domain that recognizes and binds with high affinity to titanium implant surfaces, fused through a rigid spacer domain with an antimicrobial domain. By varying the antimicrobial peptide domain, we were able to predict the properties of the resulting bifunctional peptides in their entirety by analyzing the sequence-structure-function relationship. These bifunctional peptides achieve: 1) nearly 100% surface coverage within minutes, a timeframe suitable for their clinical application to existing implants; 2) nearly 100% binding to a titanium surface even in the presence of contaminating serum protein; 3) durability to brushing with a commercially available electric toothbrush; and 4) retention of antimicrobial activity on the implant surface following bacterial challenge. A bifunctional peptide film can be applied to both new implants and/or repeatedly applied to previously placed implants to control bacterial colonization mitigating peri-implant disease that threatens dental implant longevity.
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Affiliation(s)
- E Cate Wisdom
- Bioengineering Program, Institute for Bioengineering Research, University of Kansas, Lawrence, USA
| | - Yan Zhou
- Herman Ostrow School of Dentistry of USC, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, USA
| | - Casey Chen
- Herman Ostrow School of Dentistry of USC, Division of Periodontology, Diagnostic Services, & Dental Hygiene University of Southern California, Los Angeles, USA
| | - Candan Tamerler
- Bioengineering Program, Institute for Bioengineering Research, University of Kansas, Lawrence, USA.,Mechanical Engineering Department, University of Kansas, Lawrence, USA
| | - Malcolm L Snead
- Herman Ostrow School of Dentistry of USC, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, USA
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25
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Novel Insights into Regulation of Human Teeth Biomineralization: Deciphering the Role of Post-Translational Modifications in a Tooth Protein Extract. Int J Mol Sci 2019; 20:ijms20164035. [PMID: 31430851 PMCID: PMC6720696 DOI: 10.3390/ijms20164035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 12/11/2022] Open
Abstract
The importance of whole protein extracts from different types of human teeth in modulating the process of teeth biomineralization is reported. There are two crucial features in protein molecules that result in efficient teeth biomineralization. Firstly, the unique secondary structure characteristics within these proteins i.e. the exclusive presence of a large amount of intrinsic disorder and secondly, the presence of post-translational modifications (PTM) like phosphorylation and glycosylation within these protein molecules. The present study accesses the structural implications of PTMs in the tooth proteins through scanning electron microscopy and transmission electron microscopy. The deglycosylated/dephosphorylated protein extracts failed to form higher-order mineralization assemblies. Furthermore, through nanoparticle tracking analysis (NTA) we have shown that dephosphorylation and deglycosylation significantly impact the biomineralization abilities of the protein extract and resulted in smaller sized clusters. Hence, we propose these post-translational modifications are indispensable for the process of teeth biomineralization. In addition to basic science, this study would be worth consideration while designing of biomimetics architecture for an efficient peptide-based teeth remineralization strategy.
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Sequence characteristics responsible for protein‐protein interactions in the intrinsically disordered regions of caseins, amelogenins, and small heat‐shock proteins. Biopolymers 2019; 110:e23319. [DOI: 10.1002/bip.23319] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/11/2019] [Accepted: 06/19/2019] [Indexed: 01/01/2023]
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Sharma V, Srinivasan A, Roychoudhury A, Rani K, Tyagi M, Dev K, Nikolajeff F, Kumar S. Characterization of protein extracts from different types of human teeth and insight in biomineralization. Sci Rep 2019; 9:9314. [PMID: 31249316 PMCID: PMC6597790 DOI: 10.1038/s41598-019-44268-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 05/09/2019] [Indexed: 12/20/2022] Open
Abstract
The present study describes an efficient method for isolation and purification of protein extracts from four types of human teeth i.e. molar, premolar, canine, and incisor. Detailed structural characterization of these protein extracts was done by Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) which showed that a major fraction of the proteins present are unstructured in nature including primarily random coils in addition to the other structures like extended beta (β) structure, poly-l-proline-type II (PPII) helix, turns, with only a small fraction constituting of ordered structures like alpha (α) helix and β sheets. These resultant labile structures give the proteins the necessary flexibility that they require to interact with a variety of substrates including different ions like calcium and phosphates and for other protein-protein interactions. We also did initial studies on the mineralization of calcium phosphate with the protein extracts. Nanoparticle tracking analysis (NTA) show an increase in the size of calcium phosphate accumulation in the presence of protein extracts. We propose that protein extracts elevate the crystallization process of calcium phosphate. Our current biophysical study provides novel insights into the structural characterization of proteins from human teeth and their implications in understanding the tooth biomineralization. As per our knowledge, this is the first report which focuses on the whole protein extraction from different types of human teeth as these extracts imitate the in vivo tooth mineralization.
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Affiliation(s)
- Vaibhav Sharma
- Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | | | - Ajoy Roychoudhury
- Department of Oral and Maxillofacial Surgery, Center for Dental Education and Research (CDER), All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Komal Rani
- Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Mitali Tyagi
- Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Kapil Dev
- Department of Biotechnology, Jamia Milia Islamia, New Delhi, India
| | - Fredrik Nikolajeff
- Department of Engineering Science, Uppsala University, Uppsala, 75105, Sweden
| | - Saroj Kumar
- Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
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Malmberg P, Norén JG, Bernin D. Molecular insights into hypomineralized enamel. Eur J Oral Sci 2019; 127:340-346. [DOI: 10.1111/eos.12619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Per Malmberg
- Department of Chemistry and Chemical Engineering Chalmers University of Technology Gothenburg Sweden
| | - Jörgen G. Norén
- Department of Pediatric Dentistry Institute of Odontology Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Diana Bernin
- Department of Chemistry and Chemical Engineering Chalmers University of Technology Gothenburg Sweden
- Swedish NMR Centre University of Gothenburg Gothenburg Sweden
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Su J, Kegulian NC, Arun Bapat R, Moradian-Oldak J. Ameloblastin Binds to Phospholipid Bilayers via a Helix-Forming Motif within the Sequence Encoded by Exon 5. ACS OMEGA 2019; 4:4405-4416. [PMID: 30873509 PMCID: PMC6410667 DOI: 10.1021/acsomega.8b03582] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Ameloblastin (Ambn), the most abundant non-amelogenin enamel protein, is intrinsically disordered and has the potential to interact with other enamel proteins and with cell membranes. Here, through multiple biophysical methods, we investigated the interactions between Ambn and large unilamellar vesicles (LUVs), whose lipid compositions mimicked cell membranes involved in epithelial cell-extracellular matrix adhesion. Using a series of Ambn Trp/Phe variants and Ambn mutants, we further showed that Ambn binds to LUVs through a highly conserved motif within the sequence encoded by exon 5. Synthetic peptides derived from different regions of Ambn confirmed that the sequence encoded by exon 5 is involved in LUV binding. Sequence analysis of Ambn across different species showed that the N-terminus of this sequence contains a highly conserved motif with a propensity to form an amphipathic helix. Mutations in the helix-forming sequence resulted in a loss of peptide binding to LUVs. Our in vitro data suggest that Ambn binds the lipid membrane directly through a conserved helical motif and have implications for biological events such as Ambn-cell interactions, Ambn signaling, and Ambn secretion via secretory vesicles.
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Elsharkawy S, Mata A. Hierarchical Biomineralization: from Nature's Designs to Synthetic Materials for Regenerative Medicine and Dentistry. Adv Healthc Mater 2018; 7:e1800178. [PMID: 29943412 DOI: 10.1002/adhm.201800178] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/08/2018] [Indexed: 12/28/2022]
Abstract
Biomineralization is a highly dynamic, yet controlled, process that many living creatures employ to develop functional tissues such as tooth enamel, bone, and others. A major goal in materials science is to create bioinspired functional structures based on the precise organization of building blocks across multiple length scales. Therefore, learning how nature has evolved to use biomineralization could inspire new ways to design and develop synthetic hierarchical materials with enhanced functionality. Toward this goal, this review dissects the current understanding of structure-function relationships of dental enamel and bone using a materials science perspective and discusses a wide range of synthetic technologies that aim to recreate their hierarchical organization and functionality. Insights into how these strategies could be applied for regenerative medicine and dentistry are also provided.
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Affiliation(s)
- Sherif Elsharkawy
- Institute of Bioengineering; Queen Mary University of London; London E1 4NS UK
- School of Engineering and Materials Science; Queen Mary University of London; London E1 4NS UK
- Institute of Dentistry; Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London E1 4NS UK
| | - Alvaro Mata
- Institute of Bioengineering; Queen Mary University of London; London E1 4NS UK
- School of Engineering and Materials Science; Queen Mary University of London; London E1 4NS UK
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Langella E, Buonanno M, Vullo D, Dathan N, Leone M, Supuran CT, De Simone G, Monti SM. Biochemical, biophysical and molecular dynamics studies on the proteoglycan-like domain of carbonic anhydrase IX. Cell Mol Life Sci 2018; 75:3283-3296. [PMID: 29564477 PMCID: PMC11105230 DOI: 10.1007/s00018-018-2798-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 12/11/2022]
Abstract
Human carbonic anhydrase IX (hCA IX) is a tumour-associated enzyme present in a limited number of normal tissues, but overexpressed in several malignant human tumours. It is a transmembrane protein, where the extracellular region consists of a greatly investigated catalytic CA domain and a much less investigated proteoglycan-like (PG) domain. Considering its important role in tumour biology, here, we report for the first time the full characterization of the PG domain, providing insights into its structural and functional features. In particular, this domain has been produced at high yields in bacterial cells and characterized by means of biochemical, biophysical and molecular dynamics studies. Results show that it belongs to the family of intrinsically disordered proteins, being globally unfolded with only some local residual polyproline II secondary structure. The observed conformational flexibility may have several important roles in tumour progression, facilitating interactions of hCA IX with partner proteins assisting tumour spreading and progression.
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Affiliation(s)
- Emma Langella
- Institute of Biostructures and Bioimaging, CNR, via Mezzocannone, 16, 80134, Naples, Italy
| | - Martina Buonanno
- Institute of Biostructures and Bioimaging, CNR, via Mezzocannone, 16, 80134, Naples, Italy
| | - Daniela Vullo
- Neurofarba Department, Section of Pharmaceutical and Nutriceutical Sciences, Università degli Studi di Firenze, Sesto Fiorentino, 50019, Florence, Italy
| | - Nina Dathan
- Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, CNR, via Mezzocannone, 16, 80134, Naples, Italy
| | - Claudiu T Supuran
- Neurofarba Department, Section of Pharmaceutical and Nutriceutical Sciences, Università degli Studi di Firenze, Sesto Fiorentino, 50019, Florence, Italy
| | - Giuseppina De Simone
- Institute of Biostructures and Bioimaging, CNR, via Mezzocannone, 16, 80134, Naples, Italy.
| | - Simona Maria Monti
- Institute of Biostructures and Bioimaging, CNR, via Mezzocannone, 16, 80134, Naples, Italy.
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Arachchige RJ, Burton SD, Lu JX, Ginovska B, Harding LK, Taylor ME, Tao J, Dohnalkova A, Tarasevich BJ, Buchko GW, Shaw WJ. Solid-State NMR Identification of Intermolecular Interactions in Amelogenin Bound to Hydroxyapatite. Biophys J 2018; 115:1666-1672. [PMID: 30415654 DOI: 10.1016/j.bpj.2018.08.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/16/2018] [Accepted: 08/22/2018] [Indexed: 01/01/2023] Open
Abstract
Biomineralization processes govern the formation of hierarchical hard tissues such as bone and teeth in living organisms, and mimicking these processes could lead to the design of new materials with specialized properties. However, such advances require structural characterization of the proteins guiding biomineral formation to understand and mimic their impact. In their "active" form, biomineralization proteins are bound to a solid surface, severely limiting our ability to use many conventional structure characterization techniques. Here, solid-state NMR spectroscopy was applied to study the intermolecular interactions of amelogenin, the most abundant protein present during the early stages of enamel formation, in self-assembled oligomers bound to hydroxyapatite. Intermolecular dipolar couplings were identified that support amelogenin dimer formation stabilized by residues toward the C-termini. These dipolar interactions were corroborated by molecular dynamics simulations. A β-sheet structure was identified in multiple regions of the protein, which is otherwise intrinsically disordered in the absence of hydroxyapatite. To our knowledge, this is the first intermolecular protein-protein interaction reported for a biomineralization protein, representing an advancement in understanding enamel development and a new general strategy toward investigating biomineralization proteins.
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Affiliation(s)
| | - Sarah D Burton
- Pacific Northwest National Laboratory, Richland, Washington
| | - Jun-Xia Lu
- Pacific Northwest National Laboratory, Richland, Washington
| | | | | | - Megan E Taylor
- Pacific Northwest National Laboratory, Richland, Washington
| | - Jinhui Tao
- Pacific Northwest National Laboratory, Richland, Washington
| | | | | | - Garry W Buchko
- Pacific Northwest National Laboratory, Richland, Washington; School of Molecular Biosciences, Washington State University, Pullman, Washington.
| | - Wendy J Shaw
- Pacific Northwest National Laboratory, Richland, Washington.
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Buchko GW, Jayasinha Arachchige R, Tao J, Tarasevich BJ, Shaw WJ. Identification of major matrix metalloproteinase-20 proteolytic processing products of murine amelogenin and tyrosine-rich amelogenin peptide using a nuclear magnetic resonance spectroscopy based method. Arch Oral Biol 2018; 93:187-194. [PMID: 29960917 DOI: 10.1016/j.archoralbio.2018.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The aim of this study was to identify major matrix metalloproteinase-20 (MMP20) proteolytic processing products of amelogenin over time and determine if the tyrosine-rich amelogenin peptide (TRAP) was a substrate of MMP20. DESIGN Recombinant15N-labeled murine amelogenin and 13C,15N-labeled TRAP were incubated with MMP20 under conditions where amelogenin self-assembles into nanospheres. Digestion products were fractionated by reverse-phase high-performance liquid chromatography at various time points. Product identification took advantage of the intrinsic disorder property of amelogenin that results in little change to its fingerprint 1H-15N heteronuclear single-quantum coherence nuclear magnetic resonance spectrum in 2% acetic acid upon removing parts of the protein, allowing cleavage site identification by observing which amide cross peaks disappear. RESULTS The primary product in five out of the six major reverse-phase high-performance liquid chromatography bands generated after a 24 h incubation of murine amelogenin with MMP20 were: S55-L163, P2-L147, P2-E162, P2-A167, and P2-R176. After 72 h these products were replaced with five major reverse-phase high-performance liquid chromatography bands containing: L46-A170, P2-S152, P2-F151, P2-W45, and short N-terminal peptides. TRAP was completely digested by MMP20 into multiple small peptides with the initial primary site of cleavage between S16 and Y17. CONCLUSIONS Identification of the major MMP20 proteolytic products of amelogenin confirm a dynamic process, with sites towards the C-terminus more rapidly attacked than sites near the N-terminus. This observation is consistent with nanosphere models where the C-terminus is exposed and the N-terminus more protected. One previously reported end-product of the MMP20 proteolytic processing of amelogenin, TRAP, is shown to be an in vitro substrate for MMP20.
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Affiliation(s)
- Garry W Buchko
- Pacific Northwest National Laboratory, Richland, WA 99352, USA; School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
| | | | - Jinhui Tao
- Pacific Northwest National Laboratory, Richland, WA 99352, USA.
| | | | - Wendy J Shaw
- Pacific Northwest National Laboratory, Richland, WA 99352, USA.
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Protein disorder–order interplay to guide the growth of hierarchical mineralized structures. Nat Commun 2018; 9:2145. [PMID: 29858566 PMCID: PMC5984621 DOI: 10.1038/s41467-018-04319-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/18/2018] [Indexed: 01/05/2023] Open
Abstract
A major goal in materials science is to develop bioinspired functional materials based on the precise control of molecular building blocks across length scales. Here we report a protein-mediated mineralization process that takes advantage of disorder–order interplay using elastin-like recombinamers to program organic–inorganic interactions into hierarchically ordered mineralized structures. The materials comprise elongated apatite nanocrystals that are aligned and organized into microscopic prisms, which grow together into spherulite-like structures hundreds of micrometers in diameter that come together to fill macroscopic areas. The structures can be grown over large uneven surfaces and native tissues as acid-resistant membranes or coatings with tuneable hierarchy, stiffness, and hardness. Our study represents a potential strategy for complex materials design that may open opportunities for hard tissue repair and provide insights into the role of molecular disorder in human physiology and pathology. There is evidence that disordered proteins play a role in the mineralization process. Here, the authors report on the development of elastin-like recombinant protein membranes using disordered-ordered interplay to investigate and guide mineralization.
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Ma CW, Zhang J, Dong XQ, Lu JX. Amyloid structure of high-order assembly of Leucine-rich amelogenin revealed by solid-state NMR. J Struct Biol 2018; 206:29-35. [PMID: 29604451 DOI: 10.1016/j.jsb.2018.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/18/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
High-order assemblies of amelogenin, the major protein in enamel protein matrix, are believed to act as the template for enamel mineral formation. The Leucine-rich amelogenin (LRAP) is a natural splice-variant of amelogenin, a functional protein in vivo, containing conserved domains of amelogenin. In this work, we showed LRAP aggregates hierarchically into assemblies with various sizes including scattered beads, beads-on-a-string and gel-like precipitations in the presence of both calcium and phosphate ions. Solid-state NMR combined with X-ray diffraction and microscopic techniques, was applied to give a picture of LRAP self-assemblies at the atomic level. Our results, for the first time, confirmed LRAP assemblies with different sizes all contained a consistent rigid segment with β-sheet secondary structure (residues 12-27) and the β-sheet segment would further assemble into amyloid-like structures.
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Affiliation(s)
- Cheng-Wei Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing-Qi Dong
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; Univeristy of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun-Xia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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Song J. Environment-transformable sequence-structure relationship: a general mechanism for proteotoxicity. Biophys Rev 2017; 10:503-516. [PMID: 29204881 DOI: 10.1007/s12551-017-0369-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/19/2017] [Indexed: 12/15/2022] Open
Abstract
In his Nobel Lecture, Anfinsen stated "the native conformation is determined by the totality of interatomic interactions and hence by the amino acid sequence, in a given environment." As aqueous solutions and membrane systems co-exist in cells, proteins are classified into membrane and non-membrane proteins, but whether one can transform one into the other remains unknown. Intriguingly, many well-folded non-membrane proteins are converted into "insoluble" and toxic forms by aging- or disease-associated factors, but the underlying mechanisms remain elusive. In 2005, we discovered a previously unknown regime of proteins seemingly inconsistent with the classic "Salting-in" dogma: "insoluble" proteins including the integral membrane fragments could be solubilized in the ion-minimized water. We have thus successfully studied "insoluble" forms of ALS-causing P56S-MSP, L126Z-SOD1, nascent SOD1 and C71G-Profilin1, as well as E. coli S1 fragments. The results revealed that these "insoluble" forms are either unfolded or co-exist with their unfolded states. Most unexpectedly, these unfolded states acquire a novel capacity of interacting with membranes energetically driven by the formation of helices/loops over amphiphilic/hydrophobic regions which universally exit in proteins but are normally locked away in their folded native states. Our studies suggest that most, if not all, proteins contain segments which have the dual ability to fold into distinctive structures in aqueous and membrane environments. The abnormal membrane interaction might initiate disease and/or aging processes; and its further coupling with protein aggregation could result in radical proteotoxicity by forming inclusions composed of damaged membranous organelles and protein aggregates. Therefore, environment-transformable sequence-structure relationship may represent a general mechanism for proteotoxicity.
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Affiliation(s)
- Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore, 119260, Singapore.
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Pandya M, Liu H, Dangaria SJ, Zhu W, Li LL, Pan S, Abufarwa M, Davis RG, Guggenheim S, Keiderling T, Luan X, Diekwisch TGH. Integrative Temporo-Spatial, Mineralogic, Spectroscopic, and Proteomic Analysis of Postnatal Enamel Development in Teeth with Limited Growth. Front Physiol 2017; 8:793. [PMID: 29114228 PMCID: PMC5660681 DOI: 10.3389/fphys.2017.00793] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022] Open
Abstract
Tooth amelogenesis is a complex process beginning with enamel organ cell differentiation and enamel matrix secretion, transitioning through changes in ameloblast polarity, cytoskeletal, and matrix organization, that affects crucial biomineralization events such as mineral nucleation, enamel crystal growth, and enamel prism organization. Here we have harvested the enamel organ including the pliable enamel matrix of postnatal first mandibular mouse molars during the first 8 days of tooth enamel development to conduct a step-wise cross-sectional analysis of the changes in the mineral and protein phase. Mineral phase diffraction pattern analysis using single-crystal, powder sample X-ray diffraction analysis indicated conversion of calcium phosphate precursors to partially fluoride substituted hydroxyapatite from postnatal day 4 (4 dpn) onwards. Attenuated total reflectance spectra (ATR) revealed a substantial elevation in phosphate and carbonate incorporation as well as structural reconfiguration between postnatal days 6 and 8. Nanoscale liquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS) demonstrated highest protein counts for ECM/cell surface proteins, stress/heat shock proteins, and alkaline phosphatase on postnatal day 2, high counts for ameloblast cytoskeletal proteins such as tubulin β5, tropomyosin, β-actin, and vimentin on postnatal day 4, and elevated levels of cofilin-1, calmodulin, and peptidyl-prolyl cis-trans isomerase on day 6. Western blot analysis of hydrophobic enamel proteins illustrated continuously increasing amelogenin levels from 1 dpn until 8 dpn, while enamelin peaked on days 1 and 2 dpn, and ameloblastin on days 1-5 dpn. In summary, these data document the substantial changes in the enamel matrix protein and mineral phase that take place during postnatal mouse molar amelogenesis from a systems biological perspective, including (i) relatively high levels of matrix protein expression during the early secretory stage on postnatal day 2, (ii) conversion of calcium phosphates to apatite, peak protein folding and stress protein counts, and increased cytoskeletal protein levels such as actin and tubulin on day 4, as well as (iii) secondary structure changes, isomerase activity, highest amelogenin levels, and peak phosphate/carbonate incorporation between postnatal days 6 and 8. Together, this study provides a baseline for a comprehensive understanding of the mineralogic and proteomic events that contribute to the complexity of mammalian tooth enamel development.
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Affiliation(s)
- Mirali Pandya
- Texas A&M Center for Craniofacial Research and Diagnosis, Dallas, TX, United States
| | - Hui Liu
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
| | - Smit J Dangaria
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
| | - Weiying Zhu
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Leo L Li
- Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Shuang Pan
- Brodie Laboratory for Craniofacial Genetics, University of Illinois at Chicago, Chicago, IL, United States
| | - Moufida Abufarwa
- Texas A&M Center for Craniofacial Research and Diagnosis, Dallas, TX, United States
| | - Roderick G Davis
- Proteomics Center of Excellence, Northwestern University, Evanston, IL, United States
| | - Stephen Guggenheim
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, 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
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Pegoraro M, Matić S, Pergolizzi B, Iannarelli L, Rossi AM, Morra M, Noris E. Cloning and Expression Analysis of Human Amelogenin in Nicotiana benthamiana Plants by Means of a Transient Expression System. Mol Biotechnol 2017; 59:425-434. [PMID: 28801830 DOI: 10.1007/s12033-017-0030-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Enamel is the covering tissue of teeth, made of regularly arranged hydroxyapatite crystals deposited on an organic matrix composed of 90% amelogenin that is completely degraded at the end of the enamel formation process. Amelogenin has a biomineralizing activity, forming nanoparticles or nanoribbons that guide hydroxyapatite deposit, and regenerative functions in bone and vascular tissue and in wound healing. Biotechnological products containing amelogenin seem to facilitate these processes. Here, we describe the production of human amelogenin in plants by transient transformation of Nicotiana benthamiana with constructs carrying synthetic genes with optimized human or plant codons. Both genes yielded approximately 500 µg of total amelogenin per gram of fresh leaf tissue. Two purification procedures based on affinity chromatography or on intrinsic solubility properties of the protein were followed, yielding from 12 to 150 µg of amelogenin per gram of fresh leaf tissue, respectively, at different purity. The identity of the plant-made human amelogenin was confirmed by MALDI-TOF-MS analysis of peptides generated following chymotrypsin digestion. Using dynamic light scattering, we showed that plant extracts made in acetic acid containing human amelogenin have a bimodal distribution of agglomerates, with hydrodynamic diameters of 22.8 ± 3.8 and 389.5 ± 86.6 nm. To the best of our knowledge, this is the first report of expression of human amelogenin in plants, offering the possibility to use this plant-made protein for nanotechnological applications.
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Affiliation(s)
- Mattia Pegoraro
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Strada delle Cacce 73, 10135, Turin, Italy
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Entomologia, University of Torino, Grugliasco (TO), Italy
| | - Slavica Matić
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Strada delle Cacce 73, 10135, Turin, Italy
- AGROINNOVA, University of Torino, Grugliasco (TO), Italy
| | - Barbara Pergolizzi
- Department of Clinical and Biological Sciences, University of Torino, AOU San Luigi, 10043, Orbassano (TO), Italy
| | - Luca Iannarelli
- Istituto Nazionale di Ricerca Metrologica, INRiM, Strada delle Cacce 91, 10135, Turin, Italy
| | - Andrea M Rossi
- Istituto Nazionale di Ricerca Metrologica, INRiM, Strada delle Cacce 91, 10135, Turin, Italy
| | - Marco Morra
- NobilBio Ricerche s.r.l, Via Valcastellana, 28, 14037, Portacomaro (AT), Italy
| | - Emanuela Noris
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Strada delle Cacce 73, 10135, Turin, Italy.
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Yamazaki H, Beniash E, Yamakoshi Y, Simmer JP, Margolis HC. Protein Phosphorylation and Mineral Binding Affect the Secondary Structure of the Leucine-Rich Amelogenin Peptide. Front Physiol 2017; 8:450. [PMID: 28706493 PMCID: PMC5489624 DOI: 10.3389/fphys.2017.00450] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/14/2017] [Indexed: 12/31/2022] Open
Abstract
Previously, we have shown that serine-16 phosphorylation in native full-length porcine amelogenin (P173) and the Leucine-Rich Amelogenin Peptide (LRAP(+P)), an alternative amelogenin splice product, affects protein assembly and mineralization in vitro. Notably, P173 and LRAP(+P) stabilize amorphous calcium phosphate (ACP) and inhibit hydroxyapatite (HA) formation, while non-phosphorylated counterparts (rP172, LRAP(-P)) guide the growth of ordered bundles of HA crystals. Based on these findings, we hypothesize that the phosphorylation of full-length amelogenin and LRAP induces conformational changes that critically affect its capacity to interact with forming calcium phosphate mineral phases. To test this hypothesis, we have utilized Fourier transform infrared spectroscopy (FTIR) to determine the secondary structure of LRAP(-P) and LRAP(+P) in the absence/presence of calcium and selected mineral phases relevant to amelogenesis; i.e., hydroxyapatite (HA: an enamel crystal prototype) and (ACP: an enamel crystal precursor phase). Aqueous solutions of LRAP(-P) or LRAP(+P) were prepared with or without 7.5 mM of CaCl2 at pH 7.4. FTIR spectra of each solution were obtained using attenuated total reflectance, and amide-I peaks were analyzed to provide secondary structure information. Secondary structures of LRAP(+P) and LRAP(-P) were similarly assessed following incubation with suspensions of HA and pyrophosphate-stabilized ACP. Amide I spectra of LRAP(-P) and LRAP(+P) were found to be distinct from each other in all cases. Spectra analyses showed that LRAP(-P) is comprised mostly of random coil and β-sheet, while LRAP(+P) exhibits more β-sheet and α-helix with little random coil. With added Ca, the random coil content increased in LRAP(-P), while LRAP(+P) exhibited a decrease in α-helix components. Incubation of LRAP(-P) with HA or ACP resulted in comparable increases in β-sheet structure. Notably, however, LRAP(+P) secondary structure was more affected by ACP, primarily showing an increase in β-sheet structure, compared to that observed with added HA. These collective findings indicate that phosphorylation induces unique secondary structural changes that may enhance the functional capacity of native phosphorylated amelogenins like LRAP to stabilize an ACP precursor phase during early stages of enamel mineral formation.
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Affiliation(s)
- Hajime Yamazaki
- Center for Biomineralization, The Forsyth InstituteCambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental MedicineBoston, MA, United States
| | - Elia Beniash
- Department of Oral Biology, Center for Craniofacial Regeneration, McGowan Institute for Regenerative Medicine, University of PittsburghPittsburgh, PA, United States
| | - Yasuo Yamakoshi
- Department of Biochemistry and Molecular Biology, School of Dental Medicine, Tsurumi UniversityYokohama, Japan
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of DentistryAnn Arbor, MI, United States
| | - Henry C Margolis
- Center for Biomineralization, The Forsyth InstituteCambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental MedicineBoston, MA, United States
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40
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Intrinsically disordered proteins drive enamel formation via an evolutionarily conserved self-assembly motif. Proc Natl Acad Sci U S A 2017; 114:E1641-E1650. [PMID: 28196895 DOI: 10.1073/pnas.1615334114] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The formation of mineralized tissues is governed by extracellular matrix proteins that assemble into a 3D organic matrix directing the deposition of hydroxyapatite. Although the formation of bones and dentin depends on the self-assembly of type I collagen via the Gly-X-Y motif, the molecular mechanism by which enamel matrix proteins (EMPs) assemble into the organic matrix remains poorly understood. Here we identified a Y/F-x-x-Y/L/F-x-Y/F motif, evolutionarily conserved from the first tetrapods to man, that is crucial for higher order structure self-assembly of the key intrinsically disordered EMPs, ameloblastin and amelogenin. Using targeted mutations in mice and high-resolution imaging, we show that impairment of ameloblastin self-assembly causes disorganization of the enamel organic matrix and yields enamel with disordered hydroxyapatite crystallites. These findings define a paradigm for the molecular mechanism by which the EMPs self-assemble into supramolecular structures and demonstrate that this process is crucial for organization of the organic matrix and formation of properly structured enamel.
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41
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Lella M, Mahalakshmi R. Solvation driven conformational transitions in the second transmembrane domain of mycobacteriophage holin. Biopolymers 2017; 108. [DOI: 10.1002/bip.22894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/11/2016] [Accepted: 05/31/2016] [Indexed: 12/29/2022]
Affiliation(s)
- Muralikrishna Lella
- Molecular Biophysics Laboratory, Department of Biological Sciences; Indian Institute of Science Education and Research; Bhopal 462023 India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences; Indian Institute of Science Education and Research; Bhopal 462023 India
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42
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Baias M, Smith PES, Shen K, Joachimiak LA, Żerko S, Koźmiński W, Frydman J, Frydman L. Structure and Dynamics of the Huntingtin Exon-1 N-Terminus: A Solution NMR Perspective. J Am Chem Soc 2017; 139:1168-1176. [DOI: 10.1021/jacs.6b10893] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maria Baias
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Pieter E. S. Smith
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Koning Shen
- Stanford University, Stanford, California 94305, United States
| | | | - Szymon Żerko
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Wiktor Koźmiński
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Judith Frydman
- Stanford University, Stanford, California 94305, United States
| | - Lucio Frydman
- Department
of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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43
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Connelly C, Cicuto T, Leavitt J, Petty A, Litman A, Margolis HC, Gerdon AE. Dynamic interactions of amelogenin with hydroxyapatite surfaces are dependent on protein phosphorylation and solution pH. Colloids Surf B Biointerfaces 2016; 148:377-384. [PMID: 27632699 DOI: 10.1016/j.colsurfb.2016.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/03/2016] [Accepted: 09/07/2016] [Indexed: 10/21/2022]
Abstract
Amelogenin, the predominant extracellular matrix protein secreted by ameloblasts, has been shown to be essential for proper tooth enamel formation. In this study, amelogenin adsorption to hydroxyapatite (HAP) surfaces, a prototype for enamel mineral, has been studied using a quartz crystal microbalance (QCM) to interrogate effects of protein phosphorylation and solution pH. Dynamic flow-based experiments were conducted at pH 7.4 and 8.0 using native phosphorylated porcine amelogenin (P173) and recombinant non-phosphorylated porcine amelogenin (rP172). Loading capacities (μmol/m2) on HAP surfaces were calculated under all conditions and adsorption affinities (Kad) were calculated when Langmuir isotherm conditions appeared to be met. At pH 8.0, binding characteristics were remarkably similar for the two proteins. However, at pH 7.4 a higher affinity and lower surface loading for the phosphorylated P173 was found compared to any other set of conditions. This suggests that phosphorylated P173 adopts a more extended conformation than non-phosphorylated full-length amelogenin, occupying a larger footprint on the HAP surface. This surface-induced structural difference may help explain why P173 is a more effective inhibitor of spontaneous HAP formation in vitro than rP172. Differences in the viscoelastic properties of P173 and rP172 in the adsorbed state were also observed, consistent with noted differences in HAP binding. These collective findings provide new insight into the important role of amelogenin phosphorylation in the mechanism by which amelogenin regulates enamel crystal formation.
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Affiliation(s)
| | - Thomas Cicuto
- Emmanuel College, Department of Chemistry and Physics, Boston, MA 02115, USA
| | - Jason Leavitt
- Emmanuel College, Department of Chemistry and Physics, Boston, MA 02115, USA
| | - Alexander Petty
- Emmanuel College, Department of Chemistry and Physics, Boston, MA 02115, USA
| | - Amy Litman
- The Forsyth Institute, Center for Biomineralization, Department of Applied Oral Sciences, Cambridge, MA 02142, USA
| | - Henry C Margolis
- The Forsyth Institute, Center for Biomineralization, Department of Applied Oral Sciences, Cambridge, MA 02142, USA
| | - Aren E Gerdon
- Emmanuel College, Department of Chemistry and Physics, Boston, MA 02115, USA.
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44
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Apicella A, Marascio M, Colangelo V, Soncini M, Gautieri A, Plummer CJG. Molecular dynamics simulations of the intrinsically disordered protein amelogenin. J Biomol Struct Dyn 2016; 35:1813-1823. [PMID: 27366858 DOI: 10.1080/07391102.2016.1196151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Amelogenin refers to a class of intrinsically disordered proteins that are the major constituents of enamel matrix derivative (EMD), an extract of porcine fetal teeth used in regenerative periodontal therapy. Modifications in molecular conformation induced by external stresses, such as changes in temperature or pH, are known to reduce the effectiveness of EMD. However, detailed descriptions of the conformational behavior of native amelogenin are lacking in the open literature. In the present work, a molecular model for the secondary and tertiary structure of the full-length major porcine amelogenin P173 was constructed from its primary sequence by replica exchange molecular dynamics (REMD) simulations. The REMD results for isolated amelogenin molecules at different temperatures were shown to be consistent with the available spectroscopic data. They therefore represent an important first step toward the simulation of the intra- and intermolecular interactions that mediate self-organization in amelogenin and its behavior in the presence of other EMD components under conditions representative of its therapeutic application.
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Affiliation(s)
- Alessandra Apicella
- a Laboratoire de Technologie des Composites et Polymères (LTC) , Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12, CH-1015 Lausanne , Switzerland
| | - Matteo Marascio
- a Laboratoire de Technologie des Composites et Polymères (LTC) , Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12, CH-1015 Lausanne , Switzerland.,b Dipartimento di Elettronica, Informazione e Bioingegneria , Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan , Italy
| | - Vincenzo Colangelo
- b Dipartimento di Elettronica, Informazione e Bioingegneria , Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan , Italy
| | - Monica Soncini
- b Dipartimento di Elettronica, Informazione e Bioingegneria , Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan , Italy
| | - Alfonso Gautieri
- b Dipartimento di Elettronica, Informazione e Bioingegneria , Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milan , Italy
| | - Christopher J G Plummer
- a Laboratoire de Technologie des Composites et Polymères (LTC) , Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12, CH-1015 Lausanne , Switzerland
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Abstract
Interactions between enamel matrix proteins are important
for enamel biomineralization. In recent in situ studies, we
showed that the N-terminal proteolytic product of ameloblastin co-localized with
amelogenin around the prism boundaries. However, the molecular mechanisms of such
interactions are still unclear. Here, in order to determine the interacting domains
between amelogenin and ameloblastin, we designed four ameloblastin peptides derived
from different regions of the full-length protein (AB1, AB2 and AB3 at N-terminus,
and AB6 at C-terminus) and studied their interactions with recombinant amelogenin
(rP172), and the tyrosine-rich amelogenin polypeptide (TRAP). A series of amelogenin
Trp variants (rP172(W25), rP172(W45) and rP172(W161)) were also used for intrinsic
fluorescence spectroscopy. Fluorescence spectra of rP172 titrated with AB3, a peptide
encoded by exon 5 of ameloblastin, showed a shift in λmax in a
dose-dependent manner, indicating molecular interactions in the region encoded by
exon 5 of ameloblastin. Circular dichroism (CD) spectra of amelogenin titrated with
AB3 showed that amelogenin was responsible for forming α-helix in the presence of
ameloblastin. Fluorescence spectra of amelogenin Trp variants as well as the spectra
of TRAP titrated with AB3 showed that the N-terminus of amelogenin is involved in the
interaction between ameloblastin and amelogenin. We suggest that macromolecular
co-assembly between amelogenin and ameloblastin may play important roles in enamel
biomineralization. An in vitro approach to study
ameloblastin-amelogenin interactions is presented. Intrinsic fluorescence of tryptophan and Circular Dichroism
were utilized. We report that amelogenin has ameloblastin-binding ability
via its N-terminal close to Trp 25. We report that ameloblastin has amelogenin-binding ability
via a peptide encoded by exon 5. Macromolecular co-assembly between amelogenin and
ameloblastin may play important roles in enamel biomineralization.
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46
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Boskey AL, Villarreal-Ramirez E. Intrinsically disordered proteins and biomineralization. Matrix Biol 2016; 52-54:43-59. [PMID: 26807759 DOI: 10.1016/j.matbio.2016.01.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/19/2016] [Accepted: 01/19/2016] [Indexed: 01/21/2023]
Abstract
In vertebrates and invertebrates, biomineralization is controlled by the cell and the proteins they produce. A large number of these proteins are intrinsically disordered, gaining some secondary structure when they interact with their binding partners. These partners include the component ions of the mineral being deposited, the crystals themselves, the template on which the initial crystals form, and other intrinsically disordered proteins and peptides. This review speculates why intrinsically disordered proteins are so important for biomineralization, providing illustrations from the SIBLING (small integrin binding N-glycosylated) proteins and their peptides. It is concluded that the flexible structure, and the ability of the intrinsically disordered proteins to bind to a multitude of surfaces is crucial, but details on the precise-interactions, energetics and kinetics of binding remain to be determined.
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Affiliation(s)
- Adele L Boskey
- Musculoskeletal Integrity Program, Hospital for Special Surgery, New York, NY 10021, USA.
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47
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Lokappa SB, Chandrababu KB, Moradian-Oldak J. Tooth enamel protein amelogenin binds to ameloblast cell membrane-mimicking vesicles via its N-terminus. Biochem Biophys Res Commun 2015; 464:956-61. [PMID: 26188506 PMCID: PMC4532586 DOI: 10.1016/j.bbrc.2015.07.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 07/16/2015] [Indexed: 11/18/2022]
Abstract
We have recently reported that the extracellular enamel protein amelogenin has affinity to interact with phospholipids and proposed that such interactions may play key roles in enamel biomineralization as well as reported amelogenin signaling activities. Here, in order to identify the liposome-interacting domains of amelogenin we designed four different amelogenin mutants containing only a single tryptophan at positions 25, 45, 112 and 161. Circular dichroism studies of the mutants confirmed that they are structurally similar to the wild-type amelogenin. Utilizing the intrinsic fluorescence of single tryptophan residue and fluorescence resonance energy transfer [FRET], we analyzed the accessibility and strength of their binding with an ameloblast cell membrane-mimicking model membrane (ACML) and a negatively charged liposome used as a membrane model. We found that amelogenin has membrane-binding ability mainly via its N-terminal, close to residues W25 and W45. Significant blue shift was also observed in the fluorescence of a N-terminal peptide following addition of liposomes. We suggest that, among other mechanisms, enamel malformation in cases of Amelogenesis Imperfecta (AI) with mutations at the N-terminal may be the result of defective amelogenin-cell interactions.
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Affiliation(s)
- Sowmya Bekshe Lokappa
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Karthik Balakrishna Chandrababu
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA.
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48
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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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49
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Mao Y, Satchell PG, Luan X, Diekwisch TGH. SM50 repeat-polypeptides self-assemble into discrete matrix subunits and promote appositional calcium carbonate crystal growth during sea urchin tooth biomineralization. Ann Anat 2015; 203:38-46. [PMID: 26194158 DOI: 10.1016/j.aanat.2015.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/21/2015] [Accepted: 06/22/2015] [Indexed: 10/23/2022]
Abstract
The two major proteins involved in vertebrate enamel formation and echinoderm sea urchin tooth biomineralization, amelogenin and SM50, are both characterized by elongated polyproline repeat domains in the center of the macromolecule. To determine the role of polyproline repeat polypeptides in basal deuterostome biomineralization, we have mapped the localization of SM50 as it relates to crystal growth, conducted self-assembly studies of SM50 repeat polypeptides, and examined their effect on calcium carbonate and apatite crystal growth. Electron micrographs of the growth zone of Strongylocentrotus purpuratus sea urchin teeth documented a series of successive events from intravesicular mineral nucleation to mineral deposition at the interface between tooth surface and odontoblast syncytium. Using immunohistochemistry, SM50 was detected within the cytoplasm of cells associated with the developing tooth mineral, at the mineral secreting front, and adjacent to initial mineral deposits, but not in muscles and ligaments. Polypeptides derived from the SM50 polyproline alternating hexa- and hepta-peptide repeat region (SM50P6P7) formed highly discrete, donut-shaped self-assembly patterns. In calcium carbonate crystal growth studies, SM50P6P7 repeat peptides triggered the growth of expansive networks of fused calcium carbonate crystals while in apatite growth studies, SM50P6P7 peptides facilitated the growth of needle-shaped and parallel arranged crystals resembling those found in developing vertebrate enamel. In comparison, SM50P6P7 surpassed the PXX24 polypeptide repeat region derived from the vertebrate enamel protein amelogenin in its ability to promote crystal nucleation and appositional crystal growth. Together, these studies establish the SM50P6P7 polyproline repeat region as a potent regulator in the protein-guided appositional crystal growth that occurs during continuous tooth mineralization and eruption. In addition, our studies highlight the role of species-specific polyproline repeat motifs in the formation of discrete self-assembled matrices and the resulting control of mineral growth.
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Affiliation(s)
- Yelin Mao
- UIC College of Dentistry, Department of Orthodontics, USA
| | | | - Xianghong Luan
- UIC College of Dentistry, Department of Orthodontics, USA; UIC College of Dentistry, Department of Oral Biology, USA
| | - Thomas G H Diekwisch
- UIC College of Dentistry, Department of Oral Biology, USA; Baylor College of Dentistry, Department of Periodontics, USA.
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50
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Varga G, Kerémi B, Bori E, Földes A. Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts. Pancreatology 2015; 15:S55-60. [PMID: 25747281 DOI: 10.1016/j.pan.2015.01.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/28/2015] [Indexed: 12/11/2022]
Abstract
The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation.
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Affiliation(s)
- Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.
| | - Beáta Kerémi
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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