Bombyx mori silk

Raw silk was dissolved in hexafluoro-iso-propanol (HFIP) [17, 33]. A typical working concentration for spinning was 2.5% (w/v) silk fibroin in HFIP. The spinning solution was pressed through a small needle (0 80-250 pm) into a precipitation bath (methanol for Bombyx mori silk proteins and acetone for Nephila clavipes silk proteins) and the silk solution immediately precipitated as a fiber. The best performing fibers approached the maximum strength measured for native fibers of Bombyx mori, but did not achieve the mechanical properties of natural spider silk. 

Asakura, T., and Yao, J. M. (2002). C-13 CP/MAS NMR study on structural heterogeneity in Bombyx mori silk fibre and their generation by stretching. Protein Sci. 11, 2706-2713. 

Asakura, T., Sakaguchi, R., Demura, M., Manabe, T., Uyama, A., Ogawa, K., and Osanai, M. (1993). In vitro production of Bombyx-mori silk fibroin by organ-culture of the posterior silk glands—isotope labeling and fluorination of the silk fibroin. Biotech-nol. Bioeng. 41, 245-252. 

Ha, S. W., Gracz, H. S., Tonelli, A. E., and Hudson, S. M. (2005). Structural study of irregular amino acid sequences in the heavy chain of Bombyx mori silk fibroin. Biomacromolecules 6, 2563-2569. 

Inoue, S. I., Magoshi, J., Tanaka, T., Magoshi, Y., and Becker, M. (2000b). Atomic force microscopy Bombyx mori silk fibroin molecules and their higher order structure. /. Polym. Sci. BPolym. Phys. 38, 1436-1439. 

Lazo, N. D., and Downing, D. T. (1999). Crystalline regions of Bombyx mori silk fibroin may exhibit beta-turn and beta-helix conformations. Macromolecules 32, 4700-4705. Lee, K. H. (2004). Silk sericin retards the crystallization of silk fibroin. Macromol. Rapid Commun. 25, 1792-1796. 

Monti, P., Taddei, P., Freddi, G., Asakura, T., and Tsukada, M. (2001). Raman spectroscopic characterization of Bombyx mori silk fibroin Raman spectrum of silk I. J. Raman Spectrosc. 32, 103—107. 

Yang, Y. H., Shao, Z. Z., Chen, X., and Zhou, P. (2004). Optical spectroscopy to investigate the structure of regenerated Bombyx mori silk fibroin in solution. Biomacromolecules 5, 773-779. 

Bombyx mori, silk from, 11 174 22 627, 628t, 632t, 633... 

Figure 1 Polarized IR Spectra for (A) a-Helical Wool Keratin and (B) p-Sheet Stranded Bombyx mori Silk Thread 18 ...

Surface pressure vs surface area isotherms have been investigated for stable Langmuir-films formed from soluble (Bombyx mori) silk [1],... 

Demura M, Asakura T, Kuroo T. Immobilization of biocatalysts with bombyx mori silk fibroin by several kinds of physical treatment and its application to glucose sensors. Biosensors 1989, 4, 361-372. 

Asakura, T., Sugino, R., Okumura, T., and Nakazawa, Y. "The role of irregular unit, GAAS, on the secondary structure of Bombyx mori silk fibroin studied with C-13 CP/MAS NMR and wide-angle X-ray scattering". Protein Sci. 11(8), 1873-1877 (2002). 

Asakura, T., Suita, K., Kameda, T., Afonin, S., and Ulrich, A.S. "Structural role of tyrosine in Bombyx mori silk fibroin, studied by solid-state NMR and molecular mechanics on a model peptide prepared as silk I and II". Magn. Reson. Chem. 42(2), 258-266 (2004). 

Gotoh, Y., Tsukada, M., and Minoura, N. "Effect of the chemical modification of the arginyl residue in Bombyx mori silk fibroin on the attachment and growth of fibroblast cells".. Biomed. Mater. Res. 39(3), 351-357 (1998). 

Ha, S.W., Park, Y.H., and Hudson, S.M. "Dissolution of Bombyx mori silk fibroin in the calcium nitrate tetrahydrate-methanol system and aspects of wet spinning of fibroin solution". 

Huang, X.T., Shao, Z.Z., and Chen, X. "Investigation on the biodegradation behavior of Bombyx mori silk and porous regenerated fibroin scaffold". Acta Chimica Sinica 65(22), 2592-2596 (2007). 

Jin, H.J., Park, J., Valluzzi, R., Cebe, P., and Kaplan, D.L. "Biomaterial films of Bombyx mori silk fibroin with polyethylene oxide)". Biomacromolecules 5(3), 711-717 (2004). 

Marsano, E., Corsini, P., Arosio, C., Boschi, A., Mormino, M., and Freddi, G. "Wet spinning of Bombyx mori silk fibroin dissolved in N-methyl morpholine N-oxide and properties of regenerated fibres". Int. J. Biol. Macromol. 37(4), 179-188 (2005). 

Ohgo, K., Zhao, C.H., Kobayashi, M., and Asakura, T. "Preparation of non-woven nanofibers of Bombyx mori silk, Sarnia cynthia ricini silk and recombinant hybrid silk with electro-spinning method". Polymer 44(3), 841-846 (2003). 

Shen, Y., Johnson, M.A., and Martin, D.C. "Microstructural characterization of Bombyx mori silk fibers". Macromolecules 31(25), 8857-8864 (1998). 

Sukigara, S., Gandhi, M., Ayutsede, J., Micklus, M., and Ko, F. "Regeneration of Bombyx mori silk by electrospinning - part 1 Processing parameters and geometric properties". Polymer 44(19), 5721-5727 (2003). 

Yao, J.M., Masuda, H., Zhao, C.H., and Asakura, T. "Artificial spinning and characterization of silk fiber from Bombyx mori silk fibroin in hexafluoroacetone hydrate". Macromolecules 35(1), 6-9 (2002). 

S. Sukigara, M. Gandhi, J. Ayutsede, M. Micklus, F. Ko. 2003. Regeneration of Bombyx mori silk by electrospinning part FProcessing Parameters and Geometric Properties. Polymer, 44.pp. 5721-5727. 

The silk used in nineteenth century handkerchiefs no doubt came from silkworms (Bombyx mori). Silks from other creatures, particularly spiders, have equally fascinating properties. Although we all recognize that Spider-Man s power to shoot silk ropes... 

Bombyx mori silk has both crystalline and amorphous domains. In the crystalline fraction, there is a high proportion of glycine (Gly), alanine (Ala) and serine (Ser) amino acid residues, present in the ratio of 3 2 1. This reflects the presence of hexapep-tide sequences, Gly-Ala-Gly-Ala-Gly-Ser. You ve probably forgot the structure of these amino acids, which we have therefore reproduced in Figure 9-16. 

FIGURE 9-19 The rippled or pleated structure of Bombyx mori silk. 

Fig. 18 Powder X-ray patterns of degummed native silk fibroin (SF) fibers from the Bombyx mori silk worm (a), SF precipitated from a Ca(NC>3)2 -4H20/2Me0H solution (b), and SF coalesced from its y-CD-IC (c)...

Since the Ala-Gly sequence is the major one in Bombyx mori silk, the structure of this sequential polypeptide is of importance in understanding the structure of silk. In early studies of )3-(AlaGly) it was found that the X-ray powder diffraction pattern and the IR spectrum resembled that from die crystalline component of B. mori silk. The proposed APPS structure of silk (Marsh et al., 1955b) led to a more detailed analysis of the X-ray pattern of )3-(AlaGly) (Fraser et al., 1965, 1966). This, together with conformational energy analysis (Colonna-Cesari et al., 1975),... 

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