ORCID Profile
0000-0003-3497-1959
Current Organisation
University of Manchester
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Cellular Interactions (incl. Adhesion, Matrix, Cell Wall) | Biochemistry and Cell Biology | Regenerative Medicine (incl. Stem Cells and Tissue Engineering) |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Biological Sciences | Expanding Knowledge in the Medical and Health Sciences
Related Links
Publications
Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity
Publisher: Proceedings of the National Academy of Sciences
Date: 28-02-2011
Abstract: Elastin enables the reversible deformation of elastic tissues and can withstand decades of repetitive forces. Tropoelastin is the soluble precursor to elastin, the main elastic protein found in mammals. Little is known of the shape and mechanism of assembly of tropoelastin as its unique composition and propensity to self-associate has h ered structural studies. In this study, we solve the nanostructure of full-length and corresponding overlapping fragments of tropoelastin using small angle X-ray and neutron scattering, allowing us to identify discrete regions of the molecule. Tropoelastin is an asymmetric coil, with a protruding foot that encompasses the C-terminal cell interaction motif. We show that in idual tropoelastin molecules are highly extensible yet elastic without hysteresis to perform as highly efficient molecular nanosprings. Our findings shed light on how biology uses this single protein to build durable elastic structures that allow for cell attachment to an appended foot. We present a unique model for head-to-tail assembly which allows for the propagation of the molecule’s asymmetric coil through a stacked spring design.
Raman Microscopy and X-ray Diffraction, a Combined Study of Fibrillin-rich Microfibrillar Elasticity
Publisher: Elsevier BV
Date: 10-2003
Transglutaminase-Mediated Cross-Linking of Tropoelastin to Fibrillin Stabilises the Elastin Precursor Prior to Elastic Fibre Assembly
Publisher: Elsevier BV
Date: 10-2020
Crystallization and preliminary X-ray crystallographic studies on acyl-(acyl carrier protein) fromEscherichia coli
Publisher: International Union of Crystallography (IUCr)
Date: 24-01-2002
DOI: 10.1107/S0907444901020091
Abstract: Acyl carrier proteins carry the lipid substrate to the enzymes of the fatty acid synthase system. Crystals of Escherichia coli acyl carrier protein to which a butyryl group has been attached via a thioester link to the phosphopantetheine prosthetic arm have been obtained by the hanging-drop vapour-diffusion method. These crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 27.6, b = 41.6, c = 63.7 A. The asymmetric unit appears to contain one subunit, corresponding to a packing density of 2.1 A(3) Da(-1). Crystals of the selenomethionine-substituted (SeMet) protein were obtained using different conditions and belong to space group P6(3), with unit-cell parameters a = b = 63.4, c = 37.0 A, alpha = beta = 90, gamma = 120 degrees and with a monomer in the asymmetric unit (V(M) = 2.5 A(3) Da(-1)). Crystals of a SeMet butyryl-ACP I62M variant were obtained using the conditions for the native protein. Like the native crystals, these belong to space group P2(1)2(1)2(1) and have unit-cell parameters a = 27.3, b = 41.9, c = 64.5 A. A data set suitable for MAD phasing was collected from the crystals of the I62M variant to 1.8 A resolution on the ESRF beamline ID14-4.
Tropoelastin is a Flexible Molecule that Retains its Canonical Shape
Publisher: Wiley
Date: 08-10-2018
Abstract: Tropoelastin is the dominant building block of elastic fibers, which form a major component of the extracellular matrix, providing structural support to tissues and imbuing them with elasticity and resilience. Recently, the atomistic structure of human tropoelastin is described, obtained through accelerated s ling via replica exchange molecular dynamics simulations. Here, principal component analysis is used to consider the ensemble of structures accessible to tropoelastin at body temperature (37 °C) at which tropoelastin naturally self-assembles into aggregated coacervates. These coacervates are relevant because they are an essential intermediate assembly stage, where tropoelastin molecules are then cross-linked at lysine residues and integrated into growing elastic fibers. It is found that the ensemble preserves the canonical tropoelastin structure with an extended molecular body flanked by two protruding legs, and identifies variations in specific domain positioning within this global shape. Furthermore, it is found that lysine residues show a large variation in their location on the tropoelastin molecule compared with other residues. It is hypothesized that this perturbation of the lysines increases their accessibility and enhances cross-linking. Finally, the principal component modes are extracted to describe the range of tropoelastin's conformational fluctuation to validate tropoelastin's scissor-twist motion that was predicted earlier.
A negatively charged residue stabilizes the tropoelastin N-terminal region for elastic fiber assembly
Publisher: Elsevier BV
Date: 12-2014
Subtle balance of tropoelastin molecular shape and flexibility regulates dynamics and hierarchical assembly
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-02-2016
Abstract: Tropoelastin’s local and global structures dictate molecular dynamics and are essential for efficient assembly into elastin.
Role of dimerization and substrate exclusion in the regulation of bone morphogenetic protein-1 and mammalian tolloid
Publisher: Proceedings of the National Academy of Sciences
Date: 26-05-2009
Abstract: The bone morphogenetic protein (BMP)-1/tolloid metalloproteinases are evolutionarily conserved enzymes that are fundamental to dorsal–ventral patterning and tissue morphogenesis. The lack of knowledge regarding how these proteinases recognize and cleave their substrates represents a major hurdle to understanding tissue assembly and embryonic patterning. Although BMP-1 and mammalian tolloid (mTLD) are splice variants, it is puzzling why BMP-1, which lacks 3 of the 7 noncatalytic domains present in all other family members, is the most effective proteinase. Using a combination of single-particle electron microscopy, small-angle X-ray scattering, and other biophysical measurements in solution, we show that mTLD, but not BMP-1, forms a calcium-ion-dependent dimer under physiological conditions. Using a domain deletion approach, we provide evidence that EGF2, which is absent in BMP-1, is critical to the formation of the dimer. Based on a combination of structural and functional data, we propose that mTLD activity is regulated by a substrate exclusion mechanism. These results provide a mechanistic insight into how alternative splicing of the Bmp1 gene produces 2 proteinases with differing biological activities and have broad implications for regulation of BMP-1/mTLD and related proteinases during BMP signaling and tissue assembly.
Cooperative folding of intrinsically disordered domains drives assembly of a strong elongated protein
Publisher: Springer Science and Business Media LLC
Date: 06-2015
DOI: 10.1038/NCOMMS8271
Abstract: Bacteria exploit surface proteins to adhere to other bacteria, surfaces and host cells. Such proteins need to project away from the bacterial surface and resist significant mechanical forces. SasG is a protein that forms extended fibrils on the surface of Staphylococcus aureus and promotes host adherence and biofilm formation. Here we show that although monomeric and lacking covalent cross-links, SasG maintains a highly extended conformation in solution. This extension is mediated through obligate folding cooperativity of the intrinsically disordered E domains that couple non-adjacent G5 domains thermodynamically, forming interfaces that are more stable than the domains themselves. Thus, counterintuitively, the elongation of the protein appears to be dependent on the inherent instability of its domains. The remarkable mechanical strength of SasG arises from tandemly arrayed ‘cl ’ motifs within the folded domains. Our findings reveal an elegant minimal solution for the assembly of monomeric mechano-resistant tethers of variable length.
Tropoelastin Implants That Accelerate Wound Repair
Publisher: Wiley
Date: 16-02-2018
Abstract: A novel, pure, synthetic material is presented that promotes the repair of full-thickness skin wounds. The active component is tropoelastin and leverages its ability to promote new blood vessel formation and its cell recruiting properties to accelerate wound repair. Key to the technology is the use of a novel heat-based, stabilized form of human tropoelastin which allows for tunable resorption. This implantable material contributes a tailored insert that can be shaped to the wound bed, where it hydrates to form a conformable protein hydrogel. Significant benefits in the extent of wound healing, dermal repair, and regeneration of mature epithelium in healthy pigs are demonstrated. The implant is compatible with initial co-treatment with full- and split-thickness skin grafts. The implant's superiority to sterile bandaging, commercial hydrogel and dermal regeneration template products is shown. On this basis, a new concept for a prefabricated tissue repair material for point-of-care treatment of open wounds is provided.
Molecular model of human tropoelastin and implications of associated mutations
Publisher: Proceedings of the National Academy of Sciences
Date: 26-06-2018
Abstract: Tropoelastin, the precursor molecule to elastic fibers, is a large, flexible elastic protein whose structure has been the subject of investigation and debate over several decades. Here, we present the fully atomistic structure of human tropoelastin, based on molecular dynamics simulations, and validate it with experiments. We explore the functional role of two key residues by inserting alanine substitutions and explain conformational changes and variations in hierarchical assembly. We also predict essential dynamics of the molecule by building elastin network models, to explain experimentally observed differences in assembly. Finally, we study the structural and dynamic molecular changes associated with the acquired cutis laxa disorder. The approach developed here is applicable for studying structure and function of other highly disordered proteins.
X-Ray Crystallographic Studies on Butyryl-ACP Reveal Flexibility of the Structure around a Putative Acyl Chain Binding Site
Publisher: Elsevier BV
Date: 06-2002
DOI: 10.1016/S0969-2126(02)00775-X
Abstract: Acyl carrier protein (ACP) is an essential cofactor in biosynthesis of fatty acids and many other reactions that require acyl transfer steps. We have determined the first crystal structures of an acylated form of ACP from E. coli, that of butyryl-ACP. Our analysis of the molecular surface of ACP reveals a plastic hydrophobic cavity in the vicinity of the phosphopantethylated Ser36 residue that is expanded and occupied by the butyryl and beta-mercaptoethylamine moieties of the acylated 4'-phosphopantetheine group in one of our crystal forms. In the other form, the cavity is contracted, and we propose that the protein has adopted the conformation after delivery of substrate into the active site of a partner enzyme.
Tropoelastin bridge region positions the cell-interactive C terminus and contributes to elastic fiber assembly
Publisher: Proceedings of the National Academy of Sciences
Date: 10-02-2012
Abstract: The tropoelastin monomer undergoes stages of association by coacervation, deposition onto microfibrils, and cross-linking to form elastic fibers. Tropoelastin consists of an elastic N-terminal coil region and a cell-interactive C-terminal foot region linked together by a highly exposed bridge region. The bridge region is conveniently positioned to modulate elastic fiber assembly through association by coacervation and its proximity to dominant cross-linking domains. Tropoelastin constructs that either modify or remove the entire bridge and downstream regions were assessed for elastogenesis. These constructs focused on a single alanine substitution (R515A) and a truncation (M155n) at the highly conserved arginine 515 site that borders the bridge. Each form displayed less efficient coacervation, impaired hydrogel formation, and decreased dermal fibroblast attachment compared to wild-type tropoelastin. The R515A mutant protein additionally showed reduced elastic fiber formation upon addition to human retinal pigmented epithelium cells and dermal fibroblasts. The small-angle X-ray scattering nanostructure of the R515A mutant protein revealed greater conformational flexibility around the bridge and C-terminal regions. This increased flexibility of the R515A mutant suggests that the tropoelastin R515 residue stabilizes the structure of the bridge region, which is critical for elastic fiber assembly.
Nanostructure of fibrillin-1 reveals compact conformation of EGF arrays and mechanism for extensibility
Publisher: Proceedings of the National Academy of Sciences
Date: 08-08-2006
Abstract: Fibrillin-1 is a 330-kDa multidomain extracellular matrix protein that polymerizes to form 57-nm periodic microfibrils, which are essential for all tissue elasticity. Fibrillin-1 is a member of the calcium-binding EGF repeat family and has served as a prototype for structural analyses. Nevertheless, both the detailed structure of fibrillin-1 and its organization within microfibrils are poorly understood because of the complexity of the molecule and the resistance of EGF arrays to crystallization. Here, we have used small-angle x-ray scattering and light scattering to analyze the solution structure of human fibrillin-1 and to produce ab initio structures of overlapping fragments covering 90% of the molecule. Rather than exhibiting a uniform rod shape as current models predict, the scattering data revealed a nonlinear conformation of calcium-binding EGF arrays in solution. This finding has major implications for the structures of the many other EGF-containing extracellular matrix and membrane proteins. The scattering data also highlighted a very compact, globular region of the fibrillin-1 molecule, which contains the integrin and heparan sulfate-binding sites. This finding was confirmed by calculating a 3D reconstruction of this region using electron microscopy and single-particle image analysis. Together, these data have enabled the generation of an improved model for microfibril organization and a previously undescribed mechanism for microfibril extensibility.
Targeted Modulation of Tropoelastin Structure and Assembly
Publisher: American Chemical Society (ACS)
Date: 21-11-2016
Order within disorder: Aggrecan chondroitin sulphate‐attachment region provides new structural insights into protein sequences classified as disordered
Publisher: Wiley
Date: 08-11-2010
DOI: 10.1002/PROT.22839
Domains 17-27 of tropoelastin contain key regions of contact for coacervation and contain an unusual tum-containing crosslinking domain
Publisher: Elsevier BV
Date: 03-2007
DOI: 10.1016/J.MATBIO.2006.10.002
Abstract: The central region of tropoelastin including domains 19-25 of human tropoelastin forms a hot-spot for contacts during the inter-molecular association of tropoelastin by coacervation [Wise, S.G., Mithieux, S.M., Raftery, M.J. and Weiss, A.S (2005). "Specificity in the coacervation of tropoelastin: solvent exposed lysines." Journal of Structural Biology 149: 273-81.]. We explored the physical properties of this central region using a sub-fragment bordered by domains 17-27 of human tropoelastin (SHEL 17-27) and identified the intra- and inter-molecular contacts it forms during coacervation. A homobifunctional amine reactive crosslinker (with a maximum reach of 11 A, corresponding to approximately 7 residues in an extended polypeptide chain) was used to capture these contacts and crosslinked regions were identified after protease cleavage and mass spectrometry (MS) with MS/MS verification. An intermolecular crosslink formed between the lysines at positions 353 of each strand of tropoelastin at the lowest of crosslinker concentrations and was observed in all s les tested, suggesting that this residue forms an important initial contact during coacervation. At higher crosslinker concentrations, residues K425 and K437 showed the highest levels of involvement in crosslinks. An intramolecular crosslink between these K425 and K437, separated by 11 residues, indicated that a structural bend must serve to bring these residues into close proximity. These studies were complemented by small angle X-ray scattering studies that confirmed a bend in this important subfragment of the tropoelastin molecule.
Collagen VI Microfibril Formation Is Abolished by an α2(VI) von Willebrand Factor Type A Domain Mutation in a Patient with Ullrich Congenital Muscular Dystrophy
Publisher: Elsevier BV
Date: 10-2010
Fibrillin-rich microfibrils of the extracellular matrix: Ultrastructure and assembly
Publisher: Elsevier BV
Date: 02-2001
DOI: 10.1016/S0968-4328(99)00082-7
Abstract: Fibrillin-rich microfibrils are a unique class of extensible connective tissue macromolecules. Their critical contribution to the establishment and maintenance of erse extracellular matrices was underlined by the linkage of their principal structural component fibrillin to Marfan syndrome, a heritable connective tissue disorder with pleiotropic manifestations. Microscopy and preparative techniques have contributed substantially to the understanding of microfibril structure and function. The supramolecular organisation of microfibrillar assemblies in tissues has been examined by tissue sectioning and X-ray diffraction methods. Published findings are discussed and new information reported on the organisation of microfibrils in the ciliary zonular fibrils by environmental scanning electron microscopy. This review summarises microscopy and X-ray diffraction studies that are informing current understanding of the ultrastructure of fibrillin-rich microfibrils.
A potential role for endogenous proteins as sacrificial sunscreens and antioxidants in human tissues
Publisher: Elsevier BV
Date: 08-2015
Structural and functional evidence for a substrate exclusion mechanism in mammalian tolloid like‐1 (TLL‐1) proteinase
Publisher: Wiley
Date: 30-12-2009
Related Organisations
University Of Leeds
Location: United Kingdom of Great Britain and Northern Ireland
University Of Manchester
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
Discovery Projects - Grant ID: DP220101644
Start Date: 07-2022
End Date: 06-2025
Amount: $570,000.00
Funder: Australian Research Council
View Funded Activity