title: Molecular-level characterization of elastin-like constructs and human aortic elastin.
abstract: This study aimed to characterize the structures of two elastin-like constructs, one composed of a cross-linked elastin-like polypeptide and the other one of cross-linked tropoelastin, and native aortic elastin. The structures of the insoluble materials and human aortic elastin were investigated using scanning electron microscopy. Additionally, all samples were digested with enzymes of different specificities, and the resultant peptide mixtures were characterized by ESI mass spectrometry and MALDI mass spectrometry. The MS(2) data was used to sequence linear peptides, and cross-linked species were analyzed with the recently developed software PolyLinX. This enabled the identification of two intramolecularly cross-linked peptides containing allysine aldols in the two constructs. The presence of the tetrafunctional cross-link desmosine was shown for all analyzed materials and its quantification revealed that the cross-linking degree of the two in vitro cross-linked materials was significantly lower than that of native elastin. Molecular dynamics simulations were performed, based on molecular species identified in the samples, to follow the formation of elastin cross-links. The results provide evidence for the significance of the GVGTP hinge region of domain 23 for the formation of elastin cross-links. Overall, this work provides important insight into structural similarities and differences between elastin-like constructs and native elastin. Furthermore, it represents a step toward the elucidation of the complex cross-linking pattern of mature elastin.
authors: Institute of Pharmacy, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany. Electronic address: andrea.heinz@pharmazie.uni-halle.de.
authors: Andrea
authors: A
authors: Heinz
authors: Institute of Pharmacy, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
authors: Christoph U
authors: CU
authors: Schräder
authors: Laboratoire SiRMa, FRE CNRS/URCA 3481, Université de Reims Champagne-Ardenne, Reims, France; Plateforme de Modélisation Moléculaire Multi-échelle, UFR Sciences Exactes et Naturelles, Université de Reims Champagne-Ardenne, Reims, France.
authors: Stéphanie
authors: S
authors: Baud
authors: Molecular Structure and Function, Hospital for Sick Children, Toronto, Canada.
authors: Fred W
authors: FW
authors: Keeley
authors: School of Molecular Bioscience, University of Sydney, Sydney, Australia.
authors: Suzanne M
authors: SM
authors: Mithieux
authors: School of Molecular Bioscience, University of Sydney, Sydney, Australia; Bosch Institute, University of Sydney, Sydney, Australia; Charles Perkins Centre, University of Sydney, Sydney, Australia.
authors: Anthony S
authors: AS
authors: Weiss
authors: Institute of Pharmacy, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
authors: Reinhard H H
authors: RH
authors: Neubert
authors: Institute of Pharmacy, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
authors: Christian E H
authors: CE
authors: Schmelzer
mesh_terms: D000595:Amino Acid Sequence; D001011:Aorta / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000378:metabolism; D004549:Elastin / Q000032:analysis*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D003432:Cross-Linking Reagents; D004549:Elastin
keywords: Allysine aldol; Cross-links; Desmosine; Mass spectrometry