Conformational polymorphism, stability and aggregation in spider dragline silks proteins

Dicko, Cedric; Knight, David P.; Kenney, John M.; Vollrath, Fritz

doi:10.1016/j.ijbiomac.2005.06.004

Cited by 25 publications

(29 citation statements)

References 46 publications

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“…The present effect of salt is in agreement with the so‐called hydrophobic collapse that has been recognized as a common phenomenon for proteins having hydrophobic and polar residues when subjected to higher hydrophobic forces . They are consistent with the fact that a more compact protein state has been proposed as an intermediate state prior spinning and that the Trp residues in the N‐terminal region remain buried and unexposed to solvent with the presence of high salt concentration . Finally, two distinct models have been proposed for the spider silk spinning dope.…”

Section: Discussionsupporting

confidence: 88%

Hydrodynamical properties of recombinant spider silk proteins: Effects of pH, salts and shear, and implications for the spinning process

et al. 2013

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We have investigated the effect of pH, salts and shear on the hydrodynamical diameter of recombinant major ampullate (MA) rMaSpI silk proteins in solution as a function of time using (1) H solution NMR spectroscopy. The results indicate that the silk proteins in solution are composed of two diffusing populations, a high proportion of "native" solubilized proteins and a small amount of high molecular weight oligomers. Similar results are observed with the MA gland content. Salts help maintaining the proteins in a compact form in solution over time and inhibit aggregation, the absence of salts triggering protein assembly leading to a gel state. Moreover, the aggregation kinetics of rMaSpI at low salt concentration accelerates as the pH is close to the isoelectric point of the proteins, suggesting that the pH decrease tends to slow down aggregation. The data also support the strong impact of shear on the spinning process and suggest that the assembly is driven by a nucleation conformational conversion mechanism. Thus, the adjustment of the physicochemical conditions in the ampulla seems to promote a stable, long term storage. In addition, the optimization of protein conformation as well as their unfolding and aggregation propensity in the duct leads to a specifically organized structure.

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Section: Discussionsupporting

confidence: 88%

Hydrodynamical properties of recombinant spider silk proteins: Effects of pH, salts and shear, and implications for the spinning process

et al. 2013

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“…Performing a standard multiparametric analysis of the data enables us to refine these trends, through a process of linearization 19–21. Upon plotting LS as a function of birefringence, three linear regions were immediately revealed which we define as three individual regimes (Figure 1B).…”

Section: Resultsmentioning

confidence: 99%

Distinct structural and optical regimes in natural silk spinning

et al. 2012

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This study investigates the relationship between birefringence and mechanical properties in the dragline silk of the gold orb weaving spider Nephila edulis. Using a custom birefringence-tensile testing device, we probed the orientation and water-induced swelling of fibers spun at variety of drawing rates ranging from 0.003 to 400 mm s(-1). Our results indicate that based upon drawing rate, silk fibers fall into three distinct regimes each with characteristic orientation and swelling properties. Further investigation using in situ tensile testing reveals interactions between a fiber's drawing speed, mechanical properties, and orientation that support previous model predictions. We propose that simultaneous birefringence-tensile testing provides a unique and readily accessible insight into the structural behavior of this interesting and important biomaterial.

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“…For example, the T i of folding transitions was relatively independent of dope concentrations in silks of Bombyx mori , which may suggest that 6000 yrs of farming for spinning consistency may have bred out any ancestral responses to dehydration stresses. Wild silkworms like Antherea pernii and spiders like Nephila edulis , on the other hand still live in natural habitats where desiccation is a real threat49 and their silks have built-in mechanisms to shield against this. However this may be, the technique discussed here will allow us to draw possible and testable conclusions that relate not only to molecular mechanisms but also to evolutionary drivers behind them by using clade comparisons50.…”

Section: Discussionmentioning

confidence: 99%

Differential Scanning Fluorimetry provides high throughput data on silk protein transitions.

Vollrath

Hawkins

Porter

et al. 2014

Sci Rep

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Here we present a set of measurements using Differential Scanning Fluorimetry (DSF) as an inexpensive, high throughput screening method to investigate the folding of silk protein molecules as they abandon their first native melt conformation, dehydrate and denature into their final solid filament conformation. Our first data and analyses comparing silks from spiders, mulberry and wild silkworms as well as reconstituted ‘silk' fibroin show that DSF can provide valuable insights into details of silk denaturation processes that might be active during spinning. We conclude that this technique and technology offers a powerful and novel tool to analyse silk protein transitions in detail by allowing many changes to the silk solutions to be tested rapidly with microliter scale sample sizes. Such transition mechanisms will lead to important generic insights into the folding patterns not only of silks but also of other fibrous protein (bio)polymers.

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Conformational polymorphism, stability and aggregation in spider dragline silks proteins

Cited by 25 publications

References 46 publications

Hydrodynamical properties of recombinant spider silk proteins: Effects of pH, salts and shear, and implications for the spinning process

Hydrodynamical properties of recombinant spider silk proteins: Effects of pH, salts and shear, and implications for the spinning process

Distinct structural and optical regimes in natural silk spinning

Differential Scanning Fluorimetry provides high throughput data on silk protein transitions.

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