steps of synthetic spider web production

Being able to compare the structure on a single fiber level is critical to the future of molecular directed mimic development because we can vary mechanical properties by different spinning methods.

In developing synthetic silk fibers, we first need to understand the complete secondary and tertiary structure of natural silk so that we can compare synthetic constructs to the natural material. Current efforts are focused on mimicking spider silk through synthetic proteins. The key element in taking the next step toward generating bio-based materials from spider silks will be to move from the current descriptive data to predictive knowledge. In particular, specific amino acid motifs have been identified which have been conserved for over 125 million years in all spiders that use their silk to physically trap prey. A number of spider silk genes have been cloned and sequenced by the Lewis laboratory revealing the basis for understanding the key elements of spider silk proteins with respect to their materials performance. Thus, a suite of novel traits from the level of genes to spinning physiology to silk biomechanics are associated with the unique ecology of Darwin's bark spider, presenting innovative designs for engineering biomaterials.Spider silks have the potential to provide new bio-inspired materials for numerous applications in bioenergetics and products ranging from protective clothing to artificial ligaments and tendons. Caerostris darwini's MA spinning ducts also appear unusually long, potentially facilitating alignment of silk proteins into extremely tough fibers. darwini evolved distinct proteins that may have increased its dragline's toughness, enabling giant webs. darwini dragline-producing major ampullate (MA) glands highly express a novel silk gene transcript (MaSp4) encoding a protein that diverges markedly from closely related proteins and contains abundant proline, known to confer silk extensibility, in a unique GPGPQ amino acid motif.

This extreme toughness comes from increased extensibility relative to other draglines. We also highlight different technical approaches being used to elucidate the molecular constituents of silk fibers.ĭarwin's bark spider (Caerostris darwini) produces giant orb webs from dragline silk that can be twice as tough as other silks, making it the toughest biological material. Here we summarize the molecular characteristics of the different spider fibroins, the mechanical properties and assembly process of spidroins and the advances in protein expression systems used for recombinant silk production. Novel approaches to reveal additional molecular constituents embedded in the spider fibers, as well as cloning strategies to manipulate the genes for expression, will continue to be important aspects of spider biology research. However, before spider silks can be subject to genetic engineering for commercial applications, the complete protein sequences and their functions, as well as the details of the spinning mechanism, will require additional progress and collaborative efforts in the areas of biochemistry, molecular biology and material science.

Retrieval of cDNAs and genomic DNAs encoding silk fibroins has revealed an association between the protein sequences and structure-property relationships. Spider silks are composite protein biopolymers that have complex microstructures. Spiders spin high-performance silks through the expression and assembly of tissue-restricted fibroin proteins.

Steps of synthetic spider web production