title: Recombinant exon-encoded resilins for elastomeric biomaterials.
abstract: Resilin is an elastomeric protein found in specialized regions of the cuticle of most insects, providing outstanding material properties including high resilience and fatigue lifetime for insect flight and jumping needs. Two exons (1 and 3) from the resilin gene in Drosophila melanogaster were cloned and the encoded proteins expressed as soluble products in Escherichia coli. A heat and salt precipitation method was used for efficient purification of the recombinant proteins. The proteins were solution cast from water and formed into rubber-like biomaterials via horseradish peroxidase-mediated cross-linking. Comparative studies of the two proteins expressed from the two different exons were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Circular Dichrosim (CD) for structural features. Little structural organization was found, suggesting structural order was not induced by the enzyme-mediated di-tyrosine cross-links. Atomic Force Microscopy (AFM) was used to study the elastomeric properties of the uncross-linked and cross-linked proteins. The protein from exon 1 exhibited 90% resilience in comparison to 63% for the protein from exon 3, and therefore may be the more critical domain for functional materials to mimic native resilin. Further, the cross-linking of the recombinant exon 1 via the citrate-modified photo-Fenton reaction was explored as an alternative di-tyrosine mediated polymerization method and resulted in both highly elastic and adhesive materials. The citrate-modified photo-Fenton system may be suitable for in vivo applications of resilin biomaterials.
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
authors.forename: Guokui
authors.initials: G
authors.lastname: Qin
authors.forename: Amit
authors.initials: A
authors.lastname: Rivkin
authors.forename: Shaul
authors.initials: S
authors.lastname: Lapidot
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Itan
authors.initials: I
authors.lastname: Preis
authors.forename: Shira B
authors.initials: SB
authors.lastname: Arinus
authors.forename: Or
authors.initials: O
authors.lastname: Dgany
authors.forename: Oded
authors.initials: O
authors.lastname: Shoseyov
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004331:Drosophila melanogaster / Q000378:metabolism; D004548:Elasticity / Q000187:drug effects; D020724:Elastomers / Q000494:pharmacology*; D005091:Exons / Q000235:genetics*; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D007501:Iron / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D058105:Polymerization / Q000187:drug effects; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D012995:Solubility / Q000187:drug effects; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020724:Elastomers; C045076:Fenton's reagent; D019476:Insect Proteins; D011994:Recombinant Proteins; C030951:resilin; D006861:Hydrogen Peroxide; D007501:Iron