Subtle balance of tropoelastin molecular shape and flexibility regulates dynamics and hierarchical assembly

Tropoelastin’s local and global structures dictate molecular dynamics and are essential for efficient assembly into elastin. The assembly of the tropoelastin monomer into elastin is vital for conferring elasticity on blood vessels, skin, and lungs. Tropoelastin has dual needs for flexibility and structure in self-assembly. We explore the structure-dynamics-function interplay, consider the duality of molecular order and disorder, and identify equally significant functional contributions by local and global structures. To study these organizational stratifications, we perturb a key hinge region by expressing an exon that is universally spliced out in human tropoelastins. We find a herniated nanostructure with a displaced C terminus and explain by molecular modeling that flexible helices are replaced with substantial β sheets. We see atypical higher-order cross-linking and inefficient assembly into discontinuous, thick elastic fibers. We explain this dysfunction by correlating local and global structural effects with changes in the molecule’s assembly dynamics. This work has general implications for our understanding of elastomeric proteins, which balance disordered regions with defined structural modules at multiple scales for functional assembly.

[1]  Michael Feig,et al.  MMTSB Tool Set: enhanced sampling and multiscale modeling methods for applications in structural biology. , 2004, Journal of molecular graphics & modelling.

[2]  Sarah Rauscher,et al.  Structural disorder and protein elasticity. , 2012, Advances in experimental medicine and biology.

[3]  A. Weiss,et al.  Deficient coacervation of two forms of human tropoelastin associated with supravalvular aortic stenosis. , 1999, European journal of biochemistry.

[4]  Dmitri I. Svergun,et al.  Upgrade of the small-angle X-ray scattering beamline X33 at the European Molecular Biology Laboratory, Hamburg , 2007 .

[5]  Ivet Bahar,et al.  ProDy: Protein Dynamics Inferred from Theory and Experiments , 2011, Bioinform..

[6]  Yi Zhang,et al.  Multi-species sequence comparison reveals dynamic evolution of the elastin gene that has involved purifying selection and lineage-specific insertions/deletions , 2004, BMC Genomics.

[7]  L. Grosso,et al.  Peptide sequences selected by BA4, a tropoelastin-specific monoclonal antibody, are ligands for the 67-kilodalton bovine elastin receptor. , 1993, Biochemistry.

[8]  Steven G Wise,et al.  Specificity in the coacervation of tropoelastin: solvent exposed lysines. , 2005, Journal of structural biology.

[9]  Manfred Roessle,et al.  Tropoelastin bridge region positions the cell-interactive C terminus and contributes to elastic fiber assembly , 2012, Proceedings of the National Academy of Sciences.

[10]  A. Weiss,et al.  Coacervation of tropoelastin. , 2011, Advances in colloid and interface science.

[11]  J. Rosenbloom,et al.  Characterization of the complete human elastin gene. Delineation of unusual features in the 5'-flanking region. , 1989, The Journal of biological chemistry.

[12]  Anthony S Weiss,et al.  Flexibility in the solution structure of human tropoelastin. , 2007, Biochemistry.

[13]  Hideki Sugitani,et al.  Functional Rescue of Elastin Insufficiency in Mice by the Human Elastin Gene: Implications for Mouse Models of Human Disease , 2007, Circulation research.

[14]  Y. Sugita,et al.  Replica-exchange molecular dynamics method for protein folding , 1999 .

[15]  D I Svergun,et al.  Determination of domain structure of proteins from X-ray solution scattering. , 2001, Biophysical journal.

[16]  R. Mecham,et al.  Fibrillins, fibulins, and matrix-associated glycoprotein modulate the kinetics and morphology of in vitro self-assembly of a recombinant elastin-like polypeptide. , 2008, Biochemistry.

[17]  I. Bahar,et al.  Normal mode analysis of biomolecular structures: functional mechanisms of membrane proteins. , 2010, Chemical reviews.

[18]  M. Karplus,et al.  CHARMM: A program for macromolecular energy, minimization, and dynamics calculations , 1983 .

[19]  Anthony S Weiss,et al.  Tropoelastin as a thermodynamically unfolded premolten globule protein: The effect of trimethylamine N-oxide on structure and coacervation. , 2009, Archives of biochemistry and biophysics.

[20]  Dmitri I Svergun,et al.  Correlation Map, a goodness-of-fit test for one-dimensional X-ray scattering spectra , 2015, Nature Methods.

[21]  C. H. Hill,et al.  Multiple Roles for Elastic Fibers in the Skin , 2005, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[22]  Hiroshi Wachi,et al.  Development of a new in vitro model of elastic fiber assembly in human pigmented epithelial cells. , 2005, Clinical biochemistry.

[23]  Nasim Annabi,et al.  Synthesis of highly porous crosslinked elastin hydrogels and their interaction with fibroblasts in vitro. , 2009, Biomaterials.

[24]  I Pasquali-Ronchetti,et al.  Elastic fiber during development and aging , 1997, Microscopy research and technique.

[25]  Jin Ho Chung,et al.  Modulation of elastin exon 26A mRNA and protein expression in human skin in vivo , 2009, Experimental dermatology.

[26]  Dmitri I. Svergun,et al.  PRIMUS: a Windows PC-based system for small-angle scattering data analysis , 2003 .

[27]  Dmitri I. Svergun,et al.  Uniqueness of ab initio shape determination in small-angle scattering , 2003 .

[28]  W. Wriggers,et al.  Exploring global distortions of biological macromolecules and assemblies from low-resolution structural information and elastic network theory. , 2002, Journal of molecular biology.

[29]  Dan W. Urry,et al.  The change in Gibbs free energy for hydrophobic association. Derivation and evaluation by means of inverse temperature transitions , 2004 .

[30]  Stuart A. Cain,et al.  Epithelial–mesenchymal status influences how cells deposit fibrillin microfibrils , 2014, Journal of Cell Science.

[31]  A. Weiss,et al.  Synthetic elastin hydrogels derived from massive elastic assemblies of self-organized human protein monomers. , 2004, Biomaterials.

[32]  J. Cirulis,et al.  Structural determinants of cross-linking and hydrophobic domains for self-assembly of elastin-like polypeptides. , 2005, Biochemistry.

[33]  K Schulten,et al.  VMD: visual molecular dynamics. , 1996, Journal of molecular graphics.

[34]  K. Takano.  ON SOLUTION OF , 1983 .

[35]  A. Weiss,et al.  Domain 26 of Tropoelastin Plays a Dominant Role in Association by Coacervation* , 2000, The Journal of Biological Chemistry.

[36]  Tirion,et al.  Large Amplitude Elastic Motions in Proteins from a Single-Parameter, Atomic Analysis. , 1996, Physical review letters.

[37]  P. Flory,et al.  Statistical Mechanics of Cross‐Linked Polymer Networks I. Rubberlike Elasticity , 1943 .

[38]  Dean Y. Li,et al.  Elastin is an essential determinant of arterial morphogenesis , 1998, Nature.

[39]  J A Pierce,et al.  Marked longevity of human lung parenchymal elastic fibers deduced from prevalence of D-aspartate and nuclear weapons-related radiocarbon. , 1991, The Journal of clinical investigation.

[40]  K. Hinsen.  Analysis of domain motions by approximate normal mode calculations , 1998, Proteins.

[41]  Nasim Annabi,et al.  The fabrication of elastin-based hydrogels using high pressure CO(2). , 2009, Biomaterials.

[42]  D. Ming,et al.  How to describe protein motion without amino acid sequence and atomic coordinates , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[43]  A. Oberhauser,et al.  Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity , 2011, Proceedings of the National Academy of Sciences.

[44]  F. Keeley,et al.  Cooperativity between the Hydrophobic and Cross-linking Domains of Elastin* , 2006, Journal of Biological Chemistry.

[45]  John Parkinson,et al.  Polymorphisms in the Human Tropoelastin Gene Modify In Vitro Self-Assembly and Mechanical Properties of Elastin-Like Polypeptides , 2012, PloS one.

[46]  Hideki Sugitani,et al.  Alternative Splicing and Tissue-specific Elastin Misassembly Act as Biological Modifiers of Human Elastin Gene Frameshift Mutations Associated with Dominant Cutis Laxa* , 2012, The Journal of Biological Chemistry.

[47]  M. Karplus,et al.  Effective energy function for proteins in solution , 1999, Proteins.

[48]  N. Sreerama,et al.  Estimation of protein secondary structure from circular dichroism spectra: comparison of CONTIN, SELCON, and CDSSTR methods with an expanded reference set. , 2000, Analytical biochemistry.

[49]  Pierre Baldi,et al.  SCRATCH: a protein structure and structural feature prediction server , 2005, Nucleic Acids Res..

[50]  Ji-Xin Cheng,et al.  Imaging arterial cells, atherosclerosis, and restenosis by multimodal nonlinear optical microscopy , 2008, SPIE BiOS.

[51]  A. Weiss,et al.  Domains 17-27 of tropoelastin contain key regions of contact for coacervation and contain an unusual turn-containing crosslinking domain. , 2007, Matrix biology : journal of the International Society for Matrix Biology.

[52]  U. Kucich,et al.  Structure of the elastin gene and alternative splicing of elastin mRNA: implications for human disease. , 1989, American journal of medical genetics.

[53]  Andras Czirok,et al.  Elastic fiber formation: A dynamic view of extracellular matrix assembly using timer reporters , 2006, Journal of cellular physiology.

[54]  Christopher W. Macosko,et al.  Swelling Behavior of γ-Irradiation Cross-Linked Elastomeric Polypentapeptide-Based Hydrogels , 2001 .

[55]  Steven G Wise,et al.  A model two-component system for studying the architecture of elastin assembly in vitro. , 2005, Journal of structural biology.