SSEXSY · Spider silk extrusion systems
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-01-01 → 2007-12-31
- EU contribution
- €171,861
- Participants
- 1
- Scheme
- TOK
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Results in brief
Final Activity Report Summary - SSEXSY (Spider silk extrusion systems)
The c-terminal sequences of spidroins derived from different glands are non-repetitive and highly conserved. These close relationships underline the high importance of these peculiar sequences and suggest a special role the c-termini play for the production and properties of the silks. Several functions have been attributed to the c-terminal sequences of major ampullate silks. They might represent signal peptides or be necessary for the solubility of the spidroins in the highly concentrated spinning dope. We analysed the c-termini of spidroins derived from the major ampullate gland of spiders of the genus nephila. Their secondary structures and biochemical data of expressed fusion proteins predicted that the presence of c-termini influenced the conformation and solubility of spidroins. Our sequence and biochemical analyses argued for a structural role the c-termini played for the spidroins. The fact that recombinant c-terminal sequences formed dimers under non-reducing conditions and the lack of dimerisation of the similar structured MiSps lacking the c-terminal cysteine strongly suggested that the latter contributed to divalent intermolecular crosslinks in the Masps. Since a higher molecular weight material in non-reducing conditions was seen within the gland sac, the storage compartment of the gland and solubilised threads alike, disulfide bridge formation seemed to be already triggered shortly after spidroin synthesis and maintained during fiber spinning, which emphasised the importance of this posttranslational modification. Crosslinks introduced by disulfide bridge formation would certainly influence the alignment of spidroins in the process of crystallisation during the spinning process.
Data: CORDIS, © European Union
Project objective
Natural silks have outstanding properties, which have lead to rapidly growing interests from a wide range of industries. Thus, spider silks in particular have become benchmarks for futuristic polymer design not least because, in a world demanding sustainability, these silks are not only of superb quality but are also produced cheaply, economically and ecologically from aqueous solvents under ambient temperatures and 'impossibly' low pressures. It has, with huge investments, become possible to produce recombinant silk peptides in a number of host systems.However, major barriers remain for man's ability to match the native animal silk-protein feedstocks and fibres, which we still do not understand sufficiently. Recent work suggests that the extreme toughness o f some spider threads does not depend solely on the folding of the major component protein but also on the hierarchical structure of the multi-protein thread. For folding and hierarchy the spider's complex spinning process plays a major role.The known facts indicate that the generation of the fibres and their structural organization is the result of a complex interaction of mechanical stress, biochemical properties of the liquid spinning dope and physiological processes that may actively regulate them. Yet, the investigation of spider silks so far mainly concentrated on the aspects within the expertise of the given research groups. SSExSy will transfer and integrate knowledge about the biochemistry, molecular biology and histochemistry of spider silks to a world wide leading group in measuring the physical properties of silk and spinning dope.This will create new expertise in studying the complex interactions from the level of proteins and protein domains to structural organisation and resulting mechanical properties. Subsequently, it will allow the full assessment of the requirements for biomimetic fibre production.
Original text from CORDIS.
Participants
- THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD · OXFORDCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union