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Boudko SP, Konopka EH, Kim W, Taga Y, Mizuno K, Springer TA, Hudson BG, Moy TI, Lin FY. A recombinant technique for mapping functional sites of heterotrimeric collagen helices: Collagen IV CB3 fragment as a prototype for integrin binding. J Biol Chem 2023; 299:104901. [PMID: 37302550 PMCID: PMC10404678 DOI: 10.1016/j.jbc.2023.104901] [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: 05/08/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/13/2023] Open
Abstract
Collagen superfamily of proteins is a major component of the extracellular matrix. Defects in collagens underlie the cause of nearly 40 human genetic diseases in millions of people worldwide. Pathogenesis typically involves genetic alterations of the triple helix, a hallmark structural feature that bestows exceptional mechanical resistance to tensile forces and a capacity to bind a plethora of macromolecules. Yet, there is a paramount knowledge gap in understanding the functionality of distinct sites along the triple helix. Here, we present a recombinant technique to produce triple helical fragments for functional studies. The experimental strategy utilizes the unique capacity of the NC2 heterotrimerization domain of collagen IX to drive three α-chain selection and registering the triple helix stagger. For proof of principle, we produced and characterized long triple helical fragments of collagen IV that were expressed in a mammalian system. The heterotrimeric fragments encompassed the CB3 trimeric peptide of collagen IV, which harbors the binding motifs for α1β1 and α2β1 integrins. Fragments were characterized and shown to have a stable triple helix, post-translational modifications, and high affinity and specific binding of integrins. The NC2 technique is a universal tool for the high-yield production of heterotrimeric fragments of collagens. Fragments are suitable for mapping functional sites, determining coding sequences of binding sites, elucidating pathogenicity and pathogenic mechanisms of genetic mutations, and production of fragments for protein replacement therapy.
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Affiliation(s)
- Sergei P Boudko
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA.
| | | | - Woojin Kim
- Morphic Therapeutic, Inc, Waltham, Massachusetts, USA
| | - Yuki Taga
- Nippi Research Institute of Biomatrix, Toride, Ibaraki, Japan
| | - Kazunori Mizuno
- Nippi Research Institute of Biomatrix, Toride, Ibaraki, Japan
| | - Timothy A Springer
- Department of Biological Chemistry and Molecular Pharmacology, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Billy G Hudson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Terence I Moy
- Morphic Therapeutic, Inc, Waltham, Massachusetts, USA
| | - Fu-Yang Lin
- Morphic Therapeutic, Inc, Waltham, Massachusetts, USA.
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2
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Qiang S, Lu C, Xu F. Disrupting Effects of Osteogenesis Imperfecta Mutations Could Be Predicted by Local Hydrogen Bonding Energy. Biomolecules 2022; 12:biom12081104. [PMID: 36008998 PMCID: PMC9405839 DOI: 10.3390/biom12081104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Osteogenesis imperfecta(OI) is a disease caused by substitution in glycine residues with different amino acids in type I collagen (Gly-Xaa-Yaa)n. Collagen model peptides can capture the thermal stability loss of the helix after Gly mutations, most of which are homotrimers. However, a majority of natural collagen exists in heterotrimers. To investigate the effects of chain specific mutations in the natural state of collagen more accurately, here we introduce various lengths of side-chain amino acids into ABC-type heterotrimers. The disruptive effects of the mutations were characterized both experimentally and computationally. We found the stability decrease in the mutants was mainly caused by the disruption of backbone hydrogen bonds. Meanwhile, we found a threshold value of local hydrogen bonding energy that could predict triple helix folding or unfolding. Val caused the unfolding of triple helices, whereas Ser with a similar side-chain length did not. Structural details suggested that the side-chain hydroxyl group in Ser forms hydrogen bonds with the backbone, thereby compensating for the mutants’ decreased stability. Our study contributes to a better understanding of how OI mutations destabilize collagen triple helices and the molecular mechanisms underlying OI.
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Jorgensen M, Chmielewski J. Co-assembled Coiled-Coil Peptide Nanotubes with Enhanced Stability and Metal-Dependent Cargo Loading. ACS OMEGA 2022; 7:20945-20951. [PMID: 35755377 PMCID: PMC9219066 DOI: 10.1021/acsomega.2c01669] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/30/2022] [Indexed: 05/07/2023]
Abstract
Peptide nanotube biomaterials are attractive for their range of applications. Herein, we disclose the co-assembly of coiled-coil peptides, one with ligands for metal ions that demonstrate hierarchical assembly into nanotubes, with spatial control of the metal-binding ligands. Enhanced stability of the nanotubes to phosphate-buffered saline was successfully accomplished in a metal-dependent fashion, depending on the levels and placement of the ligand-containing coiled-coil peptide. This spatial control also allowed for site-specific labeling of the nanotubes with His-tagged fluorophores through the length of the tubes or at the termini, in a metal-dependent manner.
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Hulgan SAH, Hartgerink JD. Recent Advances in Collagen Mimetic Peptide Structure and Design. Biomacromolecules 2022; 23:1475-1489. [PMID: 35258280 DOI: 10.1021/acs.biomac.2c00028] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Collagen mimetic peptides (CMPs) fold into a polyproline type II triple helix, allowing the study of the structure and function (or misfunction) of the collagen family of proteins. This Perspective will focus on recent developments in the use of CMPs toward understanding the structure and controlling the stability of the triple helix. Triple helix assembly is influenced by various factors, including the single amino acid propensity for the triple helix fold, pairwise interactions between these amino acids, and long-range effects observed across the helix, such as bend, twist, and fraying. Important progress in creating a comprehensive and predictive understanding of these factors for peptides with exclusively natural amino acids has been made. In contrast, several groups have successfully developed unnatural amino acids that are engineered to stabilize the triple helical structure. A third approach to controlling the triple helical structure includes covalent cross-linking of the triple helix to stabilize the assembly, which eliminates the problematic equilibrium of unfolding into monomers and enforces compositional control. Advances in all these areas have resulted in significant improvements to our understanding and control of this important class of protein, allowing for the design and application of more chemically complex and well-controlled collagen mimetic biomaterials.
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Affiliation(s)
- Sarah A H Hulgan
- Rice University, Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
| | - Jeffrey D Hartgerink
- Rice University, Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
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5
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Walker DR, Alizadehmojarad AA, Kolomeisky AB, Hartgerink JD. Charge-Free, Stabilizing Amide-π Interactions Can Be Used to Control Collagen Triple-Helix Self-Assembly. Biomacromolecules 2021; 22:2137-2147. [PMID: 33881314 DOI: 10.1021/acs.biomac.1c00234] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
There is a noted lack of understood, controllable interactions for directing the organization of collagen triple helices. While the field has had success using charge-pair interactions and cation-π interactions in helix design, these alone are not adequate for achieving the degree of specificity desirable for these supramolecular structures. Furthermore, because of the reliance on electrostatic interactions, designed heterotrimeric systems have been heavily charged, a property undesirable in some applications. Amide-π interactions are a comparatively understudied class of charge-free interactions, which could potentially be harnessed for triple-helix design. Herein, we propose, validate, and utilize pairwise amino acid amide-π interactions in collagen triple-helix design. Glutamine-phenylalanine pairs, when arranged in an axial geometry, are found to exhibit a moderately stabilizing effect, while in the lateral geometry, this pair is destabilizing. Together this allows glutamine-phenylalanine pairs to effectively set the register of triple helices. In contrast, interactions between asparagine and phenylalanine appear to have little effect on triple-helical stability. After deconvoluting the contributions of these amino acids to triple-helix stability, we demonstrate these new glutamine-phenylalanine interactions in the successful design of a heterotrimeric triple helix. The results of all of these analyses are used to update our collagen triple-helix thermal stability prediction algorithm, Scoring function for Collagen Emulating Peptides' Temperature of Transition (SCEPTTr).
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6
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Wang WM, Yu CH, Chang JY, Chen TH, Chen YC, Sun YT, Wang SH, Jao SC, Cheng RP. Insertion of Pro-Hyp-Gly provides 2 kcal mol -1 stability but attenuates the specific assembly of ABC heterotrimeric collagen triple helices. Org Biomol Chem 2021; 19:1860-1866. [PMID: 33565556 DOI: 10.1039/d0ob02190c] [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
Collagen is a major structural component of the extracellular matrix and connective tissue. The key structural feature of collagen is the collagen triple helix, with a Xaa-Yaa-Gly (glycine) repeating pattern. The most frequently occurring triplet is Pro (proline)-Hyp (hydroxyproline)-Gly. The reversible thermal folding and unfolding of a series of heterotrimeric collagen triple helices with varying number of Pro-Hyp-Gly triplets were monitored by circular dichroism spectroscopy to determine the unfolding thermodynamic parameters Tm (midpoint transition temperature), ΔHTm (unfolding enthalpy), and ΔGunfold (unfolding free energy). The Tm and ΔGunfold of the heterotrimeric collagen triple helices increased with increasing number of Pro-Hyp-Gly triplets. The ΔGunfold increased by 2.0 ± 0.2 kcal mol-1 upon inserting one Pro-Hyp-Gly triplet into all three chains. The Tm difference between the most stable ABC combination and the second most stable BCC combination decreased with increasing number of Pro-Hyp-Gly triplets, even though the ΔGunfold difference remained the same. These results should be useful for tuning the stability of collagen triple helical peptides for hydrogel formation, recognition of denatured collagen triple helices as diagnostics and therapeutics, and targeted drug delivery.
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Affiliation(s)
- Wei-Ming Wang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Chen-Hsu Yu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Jing-Yuan Chang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Ting-Hsuan Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Yan-Chen Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Yi-Ting Sun
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
| | - Szu-Huan Wang
- Department of Academic Affairs and Instrument Service, and Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shu-Chuan Jao
- Department of Academic Affairs and Instrument Service, and Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Richard P Cheng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
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7
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Predicting the stability of homotrimeric and heterotrimeric collagen helices. Nat Chem 2021; 13:260-269. [DOI: 10.1038/s41557-020-00626-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
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8
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Hulgan SAH, Jalan AA, Li IC, Walker DR, Miller MD, Kosgei AJ, Xu W, Phillips GN, Hartgerink JD. Covalent Capture of Collagen Triple Helices Using Lysine–Aspartate and Lysine–Glutamate Pairs. Biomacromolecules 2020; 21:3772-3781. [DOI: 10.1021/acs.biomac.0c00878] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sarah A. H. Hulgan
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Abhishek A. Jalan
- Department of Biochemistry, University of Bayreuth, Bayreuth 95447, Germany
| | - I-Che Li
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Douglas R. Walker
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Mitchell D. Miller
- Department of Biosciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Abigael J. Kosgei
- Department of Biosciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Weijun Xu
- Department of Biosciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - George N. Phillips
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Biosciences, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Jeffrey D. Hartgerink
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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9
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Urbanek A, Elena-Real CA, Popovic M, Morató A, Fournet A, Allemand F, Delbecq S, Sibille N, Bernadó P. Site-Specific Isotopic Labeling (SSIL): Access to High-Resolution Structural and Dynamic Information in Low-Complexity Proteins. Chembiochem 2019; 21:769-775. [PMID: 31697025 DOI: 10.1002/cbic.201900583] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/05/2019] [Indexed: 12/17/2022]
Abstract
Remarkable technical progress in the area of structural biology has paved the way to study previously inaccessible targets. For example, large protein complexes can now be easily investigated by cryo-electron microscopy, and modern high-field NMR magnets have challenged the limits of high-resolution characterization of proteins in solution. However, the structural and dynamic characteristics of certain proteins with important functions still cannot be probed by conventional methods. These proteins in question contain low-complexity regions (LCRs), compositionally biased sequences where only a limited number of amino acids is repeated multiple times, which hamper their characterization. This Concept article describes a site-specific isotopic labeling (SSIL) strategy, which combines nonsense suppression and cell-free protein synthesis to overcome these limitations. An overview on how poly-glutamine tracts were made amenable to high-resolution structural studies is used to illustrate the usefulness of SSIL. Furthermore, we discuss the potential of this methodology to give further insights into the roles of LCRs in human pathologies and liquid-liquid phase separation, as well as the challenges that must be addressed in the future for the popularization of SSIL.
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Affiliation(s)
- Annika Urbanek
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Carlos A Elena-Real
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Matija Popovic
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Anna Morató
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Aurélie Fournet
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Frédéric Allemand
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Stephane Delbecq
- Laboratoire de Biologie Cellulaire et Moléculaire, (LBCM-EA4558 Vaccination Antiparasitaire), UFR Pharmacie, Université de Montpellier, 15, Av. Charles Flahault, BP 14491, 34000, Montpellier, France
| | - Nathalie Sibille
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Pau Bernadó
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
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10
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Li IC, Hulgan SAH, Walker DR, Farndale RW, Hartgerink JD, Jalan AA. Covalent Capture of a Heterotrimeric Collagen Helix. Org Lett 2019; 21:5480-5484. [DOI: 10.1021/acs.orglett.9b01771] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- I-Che Li
- Rice University Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
| | - Sarah A. H. Hulgan
- Rice University Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
| | - Douglas R. Walker
- Rice University Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
| | - Richard W. Farndale
- University of Cambridge Department of Biochemistry, Downing Site, Cambridge CB2 1QW, U.K
| | - Jeffrey D. Hartgerink
- Rice University Department of Chemistry, 6100 Main Street, Houston, Texas 77005, United States
| | - Abhishek A. Jalan
- University of Bayreuth Department of Biochemistry, Universitätsstraße 30, Bayreuth 95447, Germany
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11
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How electrostatic networks modulate specificity and stability of collagen. Proc Natl Acad Sci U S A 2018; 115:6207-6212. [PMID: 29844169 DOI: 10.1073/pnas.1802171115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
One-quarter of the 28 types of natural collagen exist as heterotrimers. The oligomerization state of collagen affects the structure and mechanics of the extracellular matrix, providing essential cues to modulate biological and pathological processes. A lack of high-resolution structural information limits our mechanistic understanding of collagen heterospecific self-assembly. Here, the 1.77-Å resolution structure of a synthetic heterotrimer demonstrates the balance of intermolecular electrostatics and hydrogen bonding that affects collagen stability and heterospecificity of assembly. Atomistic simulations and mutagenesis based on the solved structure are used to explore the contributions of specific interactions to energetics. A predictive model of collagen stability and specificity is developed for engineering novel collagen structures.
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12
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Acevedo-Jake AM, Ngo DH, Hartgerink JD. Control of Collagen Triple Helix Stability by Phosphorylation. Biomacromolecules 2017; 18:1157-1161. [PMID: 28282118 DOI: 10.1021/acs.biomac.6b01814] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The phosphorylation of the collagen triple helix plays an important role in collagen synthesis, assembly, signaling, and immune response, although no reports detailing the effect this modification has on the structure and stability of the triple helix exist. Here we investigate the changes in stability and structure resulting from the phosphorylation of collagen. Additionally, the formation of pairwise interactions between phosphorylated residues and lysine is examined. In all tested cases, phosphorylation increases helix stability. When charged-pair interactions are possible, stabilization via phosphorylation can play a very large role, resulting inasmuch as a 13.0 °C increase in triple helix stability. Two-dimensional NMR and molecular modeling are used to study the local structure of the triple helix. Our results suggest a mechanism of action for phosphorylation in the regulation of collagen and also expand upon our understanding of pairwise amino acid stabilization of the collagen triple helix.
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Affiliation(s)
- Amanda M Acevedo-Jake
- Department of Chemistry, Rice University 6100 Main Street, Houston, Texas 77005, United States
| | - Daniel H Ngo
- Department of Chemistry, Rice University 6100 Main Street, Houston, Texas 77005, United States
| | - Jeffrey D Hartgerink
- Department of Chemistry, Rice University 6100 Main Street, Houston, Texas 77005, United States
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13
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Clements KA, Acevedo-Jake AM, Walker DR, Hartgerink JD. Glycine Substitutions in Collagen Heterotrimers Alter Triple Helical Assembly. Biomacromolecules 2017; 18:617-624. [DOI: 10.1021/acs.biomac.6b01808] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katherine A. Clements
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Amanda M. Acevedo-Jake
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Douglas R. Walker
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Jeffrey D. Hartgerink
- Department of Chemistry, Rice University, 6100
Main Street, Houston, Texas 77005, United States
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14
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Abstract
Fibrillar collagens (types I, II, III, V, XI, XXIV and XXVII) constitute a sub-group within the collagen family (of which there are 28 types in humans) whose functions are to provide three-dimensional frameworks for tissues and organs. These networks confer mechanical strength as well as signalling and organizing functions through binding to cellular receptors and other components of the extracellular matrix (ECM). Here we describe the structure and assembly of fibrillar collagens, and their procollagen precursors, from the molecular to the tissue level. We show how the structure of the collagen triple-helix is influenced by the amino acid sequence, hydrogen bonding and post-translational modifications, such as prolyl 4-hydroxylation. The numerous steps in the biosynthesis of the fibrillar collagens are reviewed with particular attention to the role of prolyl 3-hydroxylation, collagen chaperones, trimerization of procollagen chains and proteolytic maturation. The multiple steps controlling fibril assembly are then discussed with a focus on the cellular control of this process in vivo. Our current understanding of the molecular packing in collagen fibrils, from different tissues, is then summarized on the basis of data from X-ray diffraction and electron microscopy. These results provide structural insights into how collagen fibrils interact with cell receptors, other fibrillar and non-fibrillar collagens and other ECM components, as well as enzymes involved in cross-linking and degradation.
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Affiliation(s)
- Jordi Bella
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - David J S Hulmes
- Tissue Biology and Therapeutic Engineering Unit (UMR5305), CNRS/Université Claude Bernard Lyon 1, Lyon, France
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