Spider silks molecular biology

Although much of the interest in biological nanostructures has focused on relatively complex functionality, cells and organisms themselves can be considered as a collection of self-assembled materials lipid bilayers, the extracellular matrix, tendon and connective tissue, skin, spider silk, cotton fiber, wood, and bone are all self-assembled biological materials, with an internal structure hierarchically ordered from the molecular to the macroscopic scale. 

In Nature, there are many examples of protein and peptide molecular self-assembly. Of the genetically engineered fibrous proteins, collagen, spider silks, and elastin have received attention due to their mechanical and biological properties which can be used for biomaterials and tissue engineering. 

The diverse class of polypeptides allows for the realization of, on the one hand, high-performance construction materials, such as dragline spider silk, microtubules, or collagen fibers. On the other hand, (multi)functional molecules or molecular assemblies can be found, for example, necessary for biocatalysis (enzymes) or for the function of the immune system (immune globulins). Moreover, proteins participate in the storage and the directed transport of materials in biological systems and are essential components for the communication in complex biosystems in form of, for example, cell-surface markers, receptors, regulators, or hormones. 

Wen, H., Lan, X., Zhang, Y., Zhao, T., Wang, Y., Kajiura, Z., Nakagaki, M., 2010. Transgenic silkworms Bombyx mori) produce recombinant spider draghne silk in cocoons. Molecular Biology Reports 37 (4), 1815-1821. 

The silks of insects like the silkworm Bombyx mori have been mentioned several times in this chapter in fact, far more is known about the biochemistry, molecular biology and genetics of the silkworm than of any spider. There are many similarities between insect silks and spider silks, e.g. the predominance of amino acids with short side chains or the occurrence of some sequence motifs, which can help to understand the general principles involved in the generation of their material properties. Yet, there are also major differences that have to be taken into account. Most insect silks are used as cocoons or protective webs in larval stages and originate in labial glands [32]. In contrast. 

Craig, C., Riekel, C., Herberstein, M.E., Weber, R.S., Kaplan, D. and Pierce, N.E., Evidence for diet effects on the composition of silk proteins produced hy spiders. Molecular Biology and Evolution, 2000, 17(12) 1904-13. 

Hayashi, C.Y. and Lewis, R.V., Evidence from flageUiform silk cDNA for the structural basis of elasticity and modular nature of spider silks. Journal of Molecular Biology, 1998, 275(5) 773-784. 

Craig, C.L., Riekel, C. Comparative architecture of silks, fibrous proteins and their encoding genes in insects and spiders. Comparative Biochemistry and Physiology B Biochemistrydc Molecular Biology, 2002,133(4), 493-507. 

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