title: Synthesis and structural characterization of silk-like materials incorporated with an elastic motif.
abstract: Genetic engineering strategies were applied to synthesize silk-like materials, [(GVPGV)(2)GG(GAGAGS)(3)AS](n). The primary structure of these materials represents the repetitive crystalline region of Bombyx mori silk fibroins incorporated with an elastic motif selected from animal elastin. The oligonucleotides were designed to encode the desired recombinant proteins and then expressed in the Escherichi coli system. The expression and purification conditions for the production of the recombinant proteins were optimized. (13)C CP/MAS NMR was used for structural characterization in the solid state, where the isotope labeling was performed using a modified M9 medium. The secondary structures of these materials are primarily governed by the designated amino acid sequence, where the B. mori silk fibroin block, (GAGAGS)(3), tends to form the crystalline region, which is interrupted by the flexible (GVPGV)(2) block. The CD data suggested that the structure of these materials was length-dependent in the solution state, i.e., a higher molecule weight leads to a higher ordered structure.
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588.
authors.forename: Juming
authors.initials: J
authors.lastname: Yao
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Asakura
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D001483:Base Sequence; D001704:Biopolymers; D015153:Blotting, Western; D004549:Elastin / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005349:Fibroins / Q000096:biosynthesis; D005353:Fibronectins; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D011108:Polymers / Q000737:chemistry*; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D047011:Silk
chemical_list: D001426:Bacterial Proteins; D001704:Biopolymers; D005353:Fibronectins; D011108:Polymers; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D047011:Silk; C089172:silk-like protein polymer; D004549:Elastin; D005349:Fibroins