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Vetyskova V, Hubalek M, Sulc J, Prochazka J, Vondrasek J, Vydra Bousova K. Proteolytic profiles of two isoforms of human AMBN expressed in E. coli by MMP-20 and KLK-4 proteases. Heliyon 2024; 10:e24564. [PMID: 38298721 PMCID: PMC10828707 DOI: 10.1016/j.heliyon.2024.e24564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/16/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024] Open
Abstract
Ameloblastin is a protein in biomineralization of tooth enamel. However recent results indicate that this is probably not its only role in an organism. Enamel matrix formation represents a complex process enabled via specific crosslinking of two proteins - the most abundant amelogenin and the ameloblastin (AMBN). The human AMBN (hAMBN) gene possesses 13 protein coding exons with alternatively spliced transcripts and the longest isoform about 447 amino acid residues. It has been described that AMBN molecules in vitro assemble into oligomers via a sequence encoded by exon 5. Enamel is formed by the processing of enamel proteins by two specific proteases - enamelysin (MMP-20) and kallikrein 4 (KLK-4). The scaffold made of AMEL and non-amelogenin proteins is cleaved and removed from the developed tooth enamel. The hAMBN is expressed in two isoforms (ISO I and II), which could lead to their different utilization determined by distinct proteolytic profiles. In this study, we compared proteolytic profiles of both isoforms of hAMBN expressed in E. coli after proteolysis by MMP-20, KLK-4, and their 1:2 mixture. Proteolysis products were analysed and cleavage sites were identified by mass spectrometry. The proteolytic profiles of two AMBN isoforms showed different results, although we have to determine that the analysed AMBN was not post-translationally modified as expressed in prokaryotic cells. These results may lead to the suggestion of potentially divergent roles of AMBN isoforms cleavage products in various cell signalling pathways such as calcium buffering or signalling cascades.
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Affiliation(s)
- Veronika Vetyskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Martin Hubalek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Josef Sulc
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
- Department of Physical and Macromolecular Chemistry, Faculty of Natural Sciences, Charles University, Hlavova 8, 128 00 Prague 2, Czech Republic
| | - Jan Prochazka
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 5, 14000, Prague, Czech Republic
| | - Jiri Vondrasek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
| | - Kristyna Vydra Bousova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 2, 16000, Prague, Czech Republic
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2
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Vetyskova V, Zouharova M, Bousova K. Production of recombinant human ameloblastin by a fully native purification pathway. Protein Expr Purif 2022; 198:106133. [PMID: 35750297 DOI: 10.1016/j.pep.2022.106133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 12/29/2022]
Abstract
Ameloblastin (Ambn) is an intrinsically disordered protein (IDP) with a specific function of forming heterogenous homooligomers. The oligomeric function is led through a specific sequence encoded by exon 5 of Ambn. Due to the IDP character of Ambn to form oligomers, protein purification is subject to many challenges. Human ameloblastin (AMBN) and its two isoforms, I and II have already been purified as a recombinant protein in a bacterial expression system and functionally characterized in vitro. However, here we present a new purification protocol for the production of native AMBN in its original formation as a homooligomeric heterogeneous IDP. The purification process consists of three chromatographic steps utilizing His-tag and Twin Strep-tag affinity chromatography, along with size exclusion and reverse affinity chromatography. The presented workflow offers the production of AMBN in sufficient yield for in vitro protein characterizations and can be used to produce both AMBN isoforms I and II.
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Affiliation(s)
- V Vetyskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic; Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague, Czech Republic
| | - M Zouharova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic; Second Faculty of Medicine, Charles University, 150 06, Prague 5, V Uvalu 84, Czech Republic
| | - K Bousova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Namesti 2, 16000, Prague, Czech Republic.
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3
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Visakan G, Su J, Moradian-Oldak J. Ameloblastin promotes polarization of ameloblast cell lines in a 3-D cell culture system. Matrix Biol 2022; 105:72-86. [PMID: 34813898 PMCID: PMC8955733 DOI: 10.1016/j.matbio.2021.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023]
Abstract
Studies on animal models with mutations in ameloblastin gene have suggested that the extracellular matrix protein ameloblastin (AMBN) plays important roles in controlling cell-matrix adhesion and ameloblast polarization during amelogenesis. In order to examine the function of AMBN in cell polarization and morphology, we developed an in vitro 3D cell culture model to examine the effect of AMBN and amelogenin (AMEL) addition on ameloblast cell lines. We further used high resolution confocal microscopy to detect expression of polarization markers in response to AMBN addition. Addition of AMBN to the 3D culture matrix resulted in the clustering and elongation (higher aspect ratio) of ALC in a dose dependent manner. The molar concentration of AMEL required to exact this response from ALC was 2.75- times greater than that of AMBN. This polarization effect of ameloblastin was attributable directly to an evolutionary conserved domain within its exon 5-encoded region. The lack of exon 6-encoded region also influenced AMBN-cell interactions but to a lesser extent. The clusters formed with AMBN were polarized with expression of E-cadherin, Par3 and Cldn1 assembly at the nascent cell-cell junctions. The elongation effect was specific to epithelial cells of ameloblastic lineage ALC and LS8 cells. Our data suggest that AMBN may play critical signaling roles in the initiation of cell polarity by acting as a communicator between cell-cell and cell-matrix interactions. Our investigation has important implications for understanding the function of ameloblastin in enamel-cell matrix adhesion and the outcomes may contribute to efforts to develop strategies for enamel tissue regeneration.
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Zhu H, Blahnová VH, Perale G, Xiao J, Betge F, Boniolo F, Filová E, Lyngstadaas SP, Haugen HJ. Xeno-Hybrid Bone Graft Releasing Biomimetic Proteins Promotes Osteogenic Differentiation of hMSCs. Front Cell Dev Biol 2020; 8:619111. [PMID: 33415112 PMCID: PMC7784409 DOI: 10.3389/fcell.2020.619111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/30/2020] [Indexed: 01/04/2023] Open
Abstract
Bone defect is a noteworthy health problem and is the second most transplanted tissue after blood. Numerous bone grafts are designed and applied in clinics. Limitations, however, from different aspects still exist, including limited supply, mechanical strength, and bioactivity. In this study, two biomimetic peptides (P2 and P6) are incorporated into a composite bioactive xeno hybrid bone graft named SmartBonePep®, with the aim to increase the bioactivity of the bone graft. The results, which include cytotoxicity, proliferation rate, confocal microscopy, gene expression, and protein qualification, successfully prove that the SmartBonePep® has multi-modal biological effects on human mesenchymal stem cells from bone marrow. The effective physical entrapment of P6 into a composite xeno-hybrid bone graft, withstanding manufacturing processes including exposure to strong organic solvents and ethylene oxide sterilization, increases the osteogenic potential of the stem cells as well as cell attachment and proliferation. P2 and P6 both show a strong biological potential and may be future candidates for enhancing the clinical performance of bone grafts.
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Affiliation(s)
- Hao Zhu
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Veronika Hefka Blahnová
- Department of Tissue Engineering, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
- Department of Biophysics, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Giuseppe Perale
- Industrie Biomediche Insubri S.A., Mezzovico-Vira, Switzerland
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria
- Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano, Switzerland
| | - Jun Xiao
- Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Felice Betge
- Industrie Biomediche Insubri S.A., Mezzovico-Vira, Switzerland
| | - Fabio Boniolo
- Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Neuherberg, Germany
| | - Eva Filová
- Department of Tissue Engineering, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
- Department of Biophysics, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Ståle Petter Lyngstadaas
- Corticalis AS, Oslo, Norway
- Department of Biomaterials, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Håvard Jostein Haugen
- Corticalis AS, Oslo, Norway
- Department of Biomaterials, Faculty of Dentistry, University of Oslo, Oslo, Norway
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5
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Characterization of AMBN I and II Isoforms and Study of Their Ca 2+-Binding Properties. Int J Mol Sci 2020; 21:ijms21239293. [PMID: 33291486 PMCID: PMC7730623 DOI: 10.3390/ijms21239293] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 01/29/2023] Open
Abstract
Ameloblastin (Ambn) as an intrinsically disordered protein (IDP) stands for an important role in the formation of enamel—the hardest biomineralized tissue commonly formed in vertebrates. The human ameloblastin (AMBN) is expressed in two isoforms: full-length isoform I (AMBN ISO I) and isoform II (AMBN ISO II), which is about 15 amino acid residues shorter than AMBN ISO I. The significant feature of AMBN—its oligomerization ability—is enabled due to a specific sequence encoded by exon 5 present at the N-terminal part in both known isoforms. In this study, we characterized AMBN ISO I and AMBN ISO II by biochemical and biophysical methods to determine their common features and differences. We confirmed that both AMBN ISO I and AMBN ISO II form oligomers in in vitro conditions. Due to an important role of AMBN in biomineralization, we further addressed the calcium (Ca2+)-binding properties of AMBN ISO I and ISO II. The binding properties of AMBN to Ca2+ may explain the role of AMBN in biomineralization and more generally in Ca2+ homeostasis processes.
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Intrinsically disordered protein domain of human ameloblastin in synthetic fusion with calmodulin increases calmodulin stability and modulates its function. Int J Biol Macromol 2020; 168:1-12. [PMID: 33290768 DOI: 10.1016/j.ijbiomac.2020.11.216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 11/21/2022]
Abstract
Constantly increasing attention to bioengineered proteins has led to the rapid development of new functional targets. Here we present the biophysical and functional characteristics of the newly designed CaM/AMBN-Ct fusion protein. The two-domain artificial target consists of calmodulin (CaM) and ameloblastin C-terminus (AMBN-Ct). CaM as a well-characterized calcium ions (Ca2+) binding protein offers plenty of options in terms of Ca2+ detection in biomedicine and biotechnologies. Highly negatively charged AMBN-Ct belongs to intrinsically disordered proteins (IDPs). CaM/AMBN-Ct was designed to open new ways of communication synergies between the domains with potential functional improvement. The character and function of CaM/AMBN-Ct were explored by biophysical and molecular modelling methods. Experimental studies have revealed increased stability and preserved CaM/AMBN-Ct function. The results of molecular dynamic simulations (MDs) outlined different interface patterns between the domains with potential allosteric communication within the fusion.
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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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8
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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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Rathsam C, Farahani RM, Hains PG, Valova VA, Charadram N, Zoellner H, Swain M, Hunter N. Characterization of inter-crystallite peptides in human enamel rods reveals contribution by the Y allele of amelogenin. J Struct Biol 2018; 204:26-37. [PMID: 29959991 DOI: 10.1016/j.jsb.2018.06.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 11/18/2022]
Abstract
Proteins of the inter-rod sheath and peptides within the narrow inter-crystallite space of the rod structure are considered largely responsible for visco-elastic and visco-plastic properties of enamel. The present study was designed to investigate putative peptides of the inter-crystallite space. Entities of 1-6 kDa extracted from enamel rods of erupted permanent teeth were analysed by mass spectrometry (MS) and shown to comprise N-terminal amelogenin (AMEL) peptides either containing or not containing exon 4 product. Other dominant entities consisted of an N-terminal peptide from ameloblastin (AMBN) and a series of the most hydrophobic peptides from serum albumin (ALBN). Amelogenin peptides encoded by the Y-chromosome allele were strongly detected in Enamel from male teeth. Location of N-terminal AMEL peptides as well as AMBN and ALBN, between apatite crystallites, was disclosed by immunogold scanning electron microscopy (SEM). Density plots confirmed the relative abundance of these products including exon 4+ AMEL peptides that have greater capacity for binding to hydroxyapatite. Hydrophilic X and Y peptides encoded in exon 4 differ only in substitution of non-polar isoleucine in Y for polar threonine in X with reduced disruption of the hydrophobic N-terminal structure in the Y form. Despite similarity of X and Y alleles of AMEL the non-coding region upstream from exon 4 shows significant variation with implications for segregation of processing of transcripts from exon 4. Detection of fragments from multiple additional proteins including keratins (KER), fetuin A (FETUA), proteinases and proteinase inhibitors, likely reflect biochemical events during enamel formation.
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Affiliation(s)
- Catherine Rathsam
- Institute of Dental Research, Westmead Institute for Medical Research and Centre for Oral Health, Westmead, New South Wales, Australia.
| | - Ramin M Farahani
- Institute of Dental Research, Westmead Institute for Medical Research and Centre for Oral Health, Westmead, New South Wales, Australia; Faculty of Dentistry, The University of Sydney, New South Wales, Australia
| | - Peter G Hains
- Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Valentina A Valova
- Children's Medical Research Institute, The University of Sydney, Westmead, New South Wales, Australia
| | - Nattida Charadram
- Institute of Dental Research, Westmead Institute for Medical Research and Centre for Oral Health, Westmead, New South Wales, Australia; Faculty of Dentistry, The University of Sydney, New South Wales, Australia
| | - Hans Zoellner
- Faculty of Dentistry, The University of Sydney, New South Wales, Australia
| | - Michael Swain
- Faculty of Dentistry, The University of Sydney, New South Wales, Australia; Faculty of Dentistry, Kuwait University, Kuwait
| | - Neil Hunter
- Institute of Dental Research, Westmead Institute for Medical Research and Centre for Oral Health, Westmead, New South Wales, Australia; Faculty of Dentistry, The University of Sydney, New South Wales, Australia
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10
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Poznar M, Hołubowicz R, Wojtas M, Gapiński J, Banachowicz E, Patkowski A, Ożyhar A, Dobryszycki P. Structural properties of the intrinsically disordered, multiple calcium ion-binding otolith matrix macromolecule-64 (OMM-64). BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1358-1371. [PMID: 28866388 DOI: 10.1016/j.bbapap.2017.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/28/2017] [Indexed: 01/28/2023]
Abstract
Fish otoliths are calcium carbonate biominerals that are involved in hearing and balance sensing. An organic matrix plays a crucial role in their formation. Otolith matrix macromolecule-64 (OMM-64) is a highly acidic, calcium-binding protein (CBP) found in rainbow trout otoliths. It is a component of high-molecular-weight aggregates, which influence the size, shape and polymorph of calcium carbonate in vitro. In this study, a protocol for the efficient expression and purification of OMM-64 was developed. For the first time, the complete structural characteristics of OMM-64 were described. Various biophysical methods were combined to show that OMM-64 occurs as an intrinsically disordered monomer. Under denaturing conditions (pH, temperature) OMM-64 exhibits folding propensity. It was determined that OMM-64 binds approximately 61 calcium ions with millimolar affinity. The folding-unfolding experiments showed that calcium ions induced the collapse of OMM-64. The effect of other counter ions present in trout endolymph on OMM-64 conformational changes was studied. The significance of disordered properties of OMM-64 and the possible function of this protein is discussed.
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Affiliation(s)
- Monika Poznar
- Wrocław University of Science and Technology, Faculty of Chemistry, Department of Biochemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Rafał Hołubowicz
- Wrocław University of Science and Technology, Faculty of Chemistry, Department of Biochemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Magdalena Wojtas
- Wrocław University of Science and Technology, Faculty of Chemistry, Department of Biochemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Jacek Gapiński
- A. Mickiewicz University, Faculty of Physics, Molecular Biophysics Division, Umultowska 85, 61-614, Poznań, Poland
| | - Ewa Banachowicz
- A. Mickiewicz University, Faculty of Physics, Molecular Biophysics Division, Umultowska 85, 61-614, Poznań, Poland
| | - Adam Patkowski
- A. Mickiewicz University, Faculty of Physics, Molecular Biophysics Division, Umultowska 85, 61-614, Poznań, Poland
| | - Andrzej Ożyhar
- Wrocław University of Science and Technology, Faculty of Chemistry, Department of Biochemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Piotr Dobryszycki
- Wrocław University of Science and Technology, Faculty of Chemistry, Department of Biochemistry, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
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11
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Stakkestad Ø, Lyngstadaas SP, Thiede B, Vondrasek J, Skålhegg BS, Reseland JE. Phosphorylation Modulates Ameloblastin Self-assembly and Ca 2+ Binding. Front Physiol 2017; 8:531. [PMID: 28798693 PMCID: PMC5529409 DOI: 10.3389/fphys.2017.00531] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/10/2017] [Indexed: 01/10/2023] Open
Abstract
Ameloblastin (AMBN), an important component of the self-assembled enamel extra cellular matrix, contains several in silico predicted phosphorylation sites. However, to what extent these sites actually are phosphorylated and the possible effects of such post-translational modifications are still largely unknown. Here we report on in vitro experiments aimed at investigating what sites in AMBN are phosphorylated by casein kinase 2 (CK2) and protein kinase A (PKA) and the impact such phosphorylation has on self-assembly and calcium binding. All predicted sites in AMBN can be phosphorylated by CK2 and/or PKA. The experiments show that phosphorylation, especially in the exon 5 derived part of the molecule, is inversely correlated with AMBN self-assembly. These results support earlier findings suggesting that AMBN self-assembly is mostly dependent on the exon 5 encoded region of the AMBN gene. Phosphorylation was significantly more efficient when the AMBN molecules were in solution and not present as supramolecular assemblies, suggesting that post-translational modification of AMBN must take place before the enamel matrix molecules self-assemble inside the ameloblast cell. Moreover, phosphorylation of exon 5, and the consequent reduction in self-assembly, seem to reduce the calcium binding capacity of AMBN suggesting that post-translational modification of AMBN also can be involved in control of free Ca2+ during enamel extra cellular matrix biomineralization. Finally, it is speculated that phosphorylation can provide a functional crossroad for AMBN either to be phosphorylated and act as monomeric signal molecule during early odontogenesis and bone formation, or escape phosphorylation to be subsequently secreted as supramolecular assemblies that partake in enamel matrix structure and mineralization.
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Affiliation(s)
- Øystein Stakkestad
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
| | - Ståle P Lyngstadaas
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
| | - Bernd Thiede
- Section for Biochemistry and Molecular Biology, Department of Biosciences, University of OsloOslo, Norway
| | - Jiri Vondrasek
- Department of Bioinformatics, Institute of Organic Chemistry and Biochemistry, Czech Academy of SciencesPrague, Czechia
| | - Bjørn S Skålhegg
- Division of Molecular Nutrition, Department of Nutrition, University of OsloOslo, Norway
| | - Janne E Reseland
- Department of Biomaterials, Institute of Clinical Dentistry, University of OsloOslo, Norway
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12
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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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13
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Lu X, Fukumoto S, Yamada Y, Evans CA, Diekwisch TG, Luan X. Ameloblastin, an Extracellular Matrix Protein, Affects Long Bone Growth and Mineralization. J Bone Miner Res 2016; 31:1235-46. [PMID: 26766111 DOI: 10.1002/jbmr.2788] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/06/2016] [Accepted: 01/08/2016] [Indexed: 11/07/2022]
Abstract
Matrix molecules such as the enamel-related calcium-binding phosphoprotein ameloblastin (AMBN) are expressed in multiple tissues, including teeth, bones, and cartilage. Here we have asked whether AMBN is of functional importance for timely long bone development and, if so, how it exerts its function related to osteogenesis. Adolescent AMBN-deficient mice (AMBN(Δ5-6) ) suffered from a 33% to 38% reduction in femur length and an 8.4% shorter trunk spinal column when compared with WT controls, whereas there was no difference between adult animals. On a cellular level, AMBN truncation resulted in a shortened growth plate and a 41% to 49% reduction in the number of proliferating tibia chondrocytes and osteoblasts. Bone marrow stromal cells (BMSCs) isolated from AMBN mutant mice displayed defects in proliferation and differentiation potential as well as cytoskeleton organization. Osteogenesis-related growth factors, such as insulin-like growth factor 1 (IGF1) and BMP7, were also significantly (46% to 73%) reduced in AMBN-deficient BMSCs. Addition of exogenous AMBN restored cytoskeleton structures in AMBN mutant BMSCs and resulted in a dramatic 400% to 600% increase in BMP2, BMP7, and Col1A expression. Block of RhoA diminished the effect of AMBN on osteogenic growth factor and matrix protein gene expression. Addition of exogenous BMP7 and IGF1 rescued the proliferation and differentiation potential of AMBN-deficient BMSCs. Confirming the effects of AMBN on long bone growth, back-crossing of mutant mice with full-length AMBN overexpressors resulted in a complete rescue of AMBN(Δ5-6) bone defects. Together, these data indicate that AMBN affects extracellular matrix production and cell adhesion properties in the long bone growth plate, resulting in altered cytoskeletal dynamics, increased osteogenesis-related gene expression, as well as osteoblast and chondrocyte proliferation. We propose that AMBN facilitates rapid long bone growth and an important growth spurt during the skeletogenesis of adolescent tooth-bearing vertebrates. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Xuanyu Lu
- Department of Oral Biology, Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, IL, USA
| | - Satoshi Fukumoto
- Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Yoshihiko Yamada
- Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Carla A Evans
- Department of Orthodontics, Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, IL, USA
| | - Thomas Gh Diekwisch
- Department of Oral Biology, Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, IL, USA
| | - Xianghong Luan
- Department of Oral Biology, Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, IL, USA.,Department of Orthodontics, Brodie Laboratory for Craniofacial Genetics, University of Illinois College of Dentistry, Chicago, IL, USA
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14
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Advances of Proteomic Sciences in Dentistry. Int J Mol Sci 2016; 17:ijms17050728. [PMID: 27187379 PMCID: PMC4881550 DOI: 10.3390/ijms17050728] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 05/01/2016] [Accepted: 05/09/2016] [Indexed: 12/13/2022] Open
Abstract
Applications of proteomics tools revolutionized various biomedical disciplines such as genetics, molecular biology, medicine, and dentistry. The aim of this review is to highlight the major milestones in proteomics in dentistry during the last fifteen years. Human oral cavity contains hard and soft tissues and various biofluids including saliva and crevicular fluid. Proteomics has brought revolution in dentistry by helping in the early diagnosis of various diseases identified by the detection of numerous biomarkers present in the oral fluids. This paper covers the role of proteomics tools for the analysis of oral tissues. In addition, dental materials proteomics and their future directions are discussed.
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15
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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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16
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Geng S, White SN, Paine ML, Snead ML. Protein Interaction between Ameloblastin and Proteasome Subunit α Type 3 Can Facilitate Redistribution of Ameloblastin Domains within Forming Enamel. J Biol Chem 2015; 290:20661-20673. [PMID: 26070558 DOI: 10.1074/jbc.m115.640185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Indexed: 11/06/2022] Open
Abstract
Enamel is a bioceramic tissue composed of thousands of hydroxyapatite crystallites aligned in parallel within boundaries fabricated by a single ameloblast cell. Enamel is the hardest tissue in the vertebrate body; however, it starts development as a self-organizing assembly of matrix proteins that control crystallite habit. Here, we examine ameloblastin, a protein that is initially distributed uniformly across the cell boundary but redistributes to the lateral margins of the extracellular matrix following secretion thus producing cell-defined boundaries within the matrix and the mineral phase. The yeast two-hybrid assay identified that proteasome subunit α type 3 (Psma3) interacts with ameloblastin. Confocal microscopy confirmed Psma3 co-distribution with ameloblastin at the ameloblast secretory end piece. Co-immunoprecipitation assay of mouse ameloblast cell lysates with either ameloblastin or Psma3 antibody identified each reciprocal protein partner. Protein engineering demonstrated that only the ameloblastin C terminus interacts with Psma3. We show that 20S proteasome digestion of ameloblastin in vitro generates an N-terminal cleavage fragment consistent with the in vivo pattern of ameloblastin distribution. These findings suggest a novel pathway participating in control of protein distribution within the extracellular space that serves to regulate the protein-mineral interactions essential to biomineralization.
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Affiliation(s)
- Shuhui Geng
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033
| | - Shane N White
- School of Dentistry, UCLA, Los Angeles, California 90095
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033
| | - Malcolm L Snead
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90033.
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17
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Lignon G, de la Dure-Molla M, Dessombz A, Berdal A, Babajko S. [Enamel: a unique self-assembling in mineral world]. Med Sci (Paris) 2015; 31:515-21. [PMID: 26059302 DOI: 10.1051/medsci/20153105013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Enamel is a unique tissue in vertebrates, acellular, formed on a labile scaffolding matrix and hypermineralized. The ameloblasts are epithelial cells in charge of amelogenesis. They secrete a number of matrix proteins degraded by enzymes during enamel mineralization. This ordered cellular and extracellular events imply that any genetic or environmental perturbation will produce indelible and recognizable defects. The specificity of defects will indicate the affected cellular process. Thus, depending on the specificity of alterations, the teratogenic event can be retrospectively established. Advances in the field allow to use enamel defects as diagnostic tools for molecular disorders. The multifunctionality of enamel peptides is presently identified from their chemical roles in mineralization to cell signaling, constituting a source of concrete innovations in regenerative medicine.
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Affiliation(s)
- Guilhem Lignon
- Laboratoire de physiopathologie orale moléculaire, Inserm UMRS 1138, centre de recherche des Cordeliers, université Paris Diderot-Paris 7, université Pierre et Marie Curie-Paris 6, université Paris Descartes-Paris 5, 15-21, rue de l'École de Médecine, 75270 Paris cedex 06, France
| | - Muriel de la Dure-Molla
- Laboratoire de physiopathologie orale moléculaire, Inserm UMRS 1138, centre de recherche des Cordeliers, université Paris Diderot-Paris 7, université Pierre et Marie Curie-Paris 6, université Paris Descartes-Paris 5, 15-21, rue de l'École de Médecine, 75270 Paris cedex 06, France - Centre de référence des malformations rares de la face et de la cavité buccale, CRMR-MAFACE, hôpital Rothschild, APHP, Paris, France
| | - Arnaud Dessombz
- Laboratoire de physiopathologie orale moléculaire, Inserm UMRS 1138, centre de recherche des Cordeliers, université Paris Diderot-Paris 7, université Pierre et Marie Curie-Paris 6, université Paris Descartes-Paris 5, 15-21, rue de l'École de Médecine, 75270 Paris cedex 06, France
| | - Ariane Berdal
- Laboratoire de physiopathologie orale moléculaire, Inserm UMRS 1138, centre de recherche des Cordeliers, université Paris Diderot-Paris 7, université Pierre et Marie Curie-Paris 6, université Paris Descartes-Paris 5, 15-21, rue de l'École de Médecine, 75270 Paris cedex 06, France - Centre de référence des malformations rares de la face et de la cavité buccale, CRMR-MAFACE, hôpital Rothschild, APHP, Paris, France
| | - Sylvie Babajko
- Laboratoire de physiopathologie orale moléculaire, Inserm UMRS 1138, centre de recherche des Cordeliers, université Paris Diderot-Paris 7, université Pierre et Marie Curie-Paris 6, université Paris Descartes-Paris 5, 15-21, rue de l'École de Médecine, 75270 Paris cedex 06, France
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18
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Mazumder P, Prajapati S, Lokappa SB, Gallon V, Moradian-Oldak J. Analysis of co-assembly and co-localization of ameloblastin and amelogenin. Front Physiol 2014; 5:274. [PMID: 25120489 PMCID: PMC4110739 DOI: 10.3389/fphys.2014.00274] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/07/2014] [Indexed: 12/17/2022] Open
Abstract
Epithelially-derived ameloblasts secrete extracellular matrix proteins including amelogenin, enamelin, and ameloblastin. Complex intermolecular interactions among these proteins are believed to be important in controlling enamel formation. Here we provide in vitro and in vivo evidence of co-assembly and co-localization of ameloblastin with amelogenin using both biophysical and immunohistochemical methods. We performed co-localization studies using immunofluorescence confocal microscopy with paraffin-embedded tissue sections from mandibular molars of mice at 1, 5, and 8 days of age. Commercially-available ameloblastin antibody (M300) against mouse ameloblastin residues 107-407 and an antibody against full-length recombinant mouse (rM179) amelogenin were used. Ameloblastin-M300 clearly reacted along the secretory face of ameloblasts from days 1-8. Quantitative co-localization was analyzed (QCA) in several configurations by choosing appropriate regions of interest (ROIs). Analysis of ROIs along the secretory face of ameloblasts revealed that at day 1, very high percentages of both the ameloblastin and amelogenin co-localized. At day 8 along the ameloblast cells the percentage of co-localization remained high for the ameloblastin whereas co-localization percentage was reduced for amelogenin. Analysis of the entire thickness on day 8 revealed no significant co-localization of amelogenin and ameloblastin. With the progress of amelogenesis and ameloblastin degradation, there was a segregation of ameloblastin and co-localization with the C-terminal region decreased. CD spectra indicated that structural changes in ameloblastin occurred upon addition of amelogenin. Our data suggest that amelogenin-ameloblastin complexes may be the functional entities at the early stage of enamel mineralization.
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Affiliation(s)
| | | | | | | | - Janet Moradian-Oldak
- Division of Biomedical Sciences, Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, USA
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19
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JÁGR M, ECKHARDT A, PATARIDIS S, BROUKAL Z, DUŠKOVÁ J, MIKŠÍK I. Proteomics of Human Teeth and Saliva. Physiol Res 2014; 63:S141-54. [DOI: 10.33549/physiolres.932702] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Teeth have been a focus of interest for many centuries – due to medical problems with them. They are the hardest part of the human body and are composed of three mineralized parts – enamel, dentin and cementum, together with the soft pulp. However, saliva also has a significant impact on tooth quality. Proteomic research of human teeth is now accelerating, and it includes all parts of the tooth. Some methodological problems still need to be overcome in this research field – mainly connected with calcified tissues. This review will provide an overview of the current state of research with focus on the individual parts of the tooth and pellicle layer as well as saliva. These proteomic results can help not only stomatology in terms of early diagnosis, identifying risk factors, and systematic control.
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Affiliation(s)
| | | | | | | | | | - I. MIKŠÍK
- Department of Analysis of Biologically Important Compounds, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic
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20
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Wald T, Osickova A, Sulc M, Benada O, Semeradtova A, Rezabkova L, Veverka V, Bednarova L, Maly J, Macek P, Sebo P, Slaby I, Vondrasek J, Osicka R. Intrinsically disordered enamel matrix protein ameloblastin forms ribbon-like supramolecular structures via an N-terminal segment encoded by exon 5. J Biol Chem 2013; 288:22333-45. [PMID: 23782691 DOI: 10.1074/jbc.m113.456012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tooth enamel, the hardest tissue in the body, is formed by the evolutionarily highly conserved biomineralization process that is controlled by extracellular matrix proteins. The intrinsically disordered matrix protein ameloblastin (AMBN) is the most abundant nonamelogenin protein of the developing enamel and a key element for correct enamel formation. AMBN was suggested to be a cell adhesion molecule that regulates proliferation and differentiation of ameloblasts. Nevertheless, detailed structural and functional studies on AMBN have been substantially limited by the paucity of the purified nondegraded protein. With this study, we have developed a procedure for production of a highly purified form of recombinant human AMBN in quantities that allowed its structural characterization. Using size exclusion chromatography, analytical ultracentrifugation, transmission electron, and atomic force microscopy techniques, we show that AMBN self-associates into ribbon-like supramolecular structures with average widths and thicknesses of 18 and 0.34 nm, respectively. The AMBN ribbons exhibited lengths ranging from tens to hundreds of nm. Deletion analysis and NMR spectroscopy revealed that an N-terminal segment encoded by exon 5 comprises two short independently structured regions and plays a key role in self-assembly of AMBN.
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Affiliation(s)
- Tomas Wald
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
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