A Materiomics Approach to Spider Silk: Protein Molecules to Webs

Abstract

The exceptional mechanical properties of hierarchical self-assembling silk biopolymers have been extensively studied experimentally and in computational investigations. A series of recent studies has been conducted to examine structure-function relationships across different length scales in silk, ranging from atomistic models of protein constituents to the spider web architecture. Silk is an exemplary natural material because its superior properties stem intrinsically from the synergistic cooperativity of hierarchically organized components, rather than from the superior properties of the building blocks themselves. It is composed of beta-sheet nanocrystals interspersed within less orderly amorphous domains, where the underlying molecular structure is dominated by weak hydrogen bonding. Protein chains are organized into fibrils, which pack together to form threads of a spider web. In this article we survey multiscale studies spanning length scales from angstroms to centimeters, from the amino acid sequence defining silk components to an atomistically derived spider web model, with the aim to bridge varying levels of hierarchy to elucidate the mechanisms by which structure at each composite level contributes to organization and material phenomena at subsequent levels. The work demonstrates that the web is a highly adapted system where both material and hierarchical structure across all length scales is critical for its functional properties.

Increasing silk fibre strength through heterogeneity of bundled fibrils

“…That being said, a molecular dynamics (MD) approach allows efficient manipulation of constitutive behaviour, such as elasticity and contact as well as interfacial failure and large deformation. As such, I use a coarse-grain mesoscopic 'bead-on-a-string' model as a platform to assess silk fibril behaviour, using general MD formulations [28,32]. Experimentally, it has been demonstrated that shearing of the silk protein solution can lead to a similar bead-on-a-string assembly at the nanometre scale [54,55].…”

“…'Could we be missing a critical structural feature, hidden in what we perceive as a structural flaw?' Undeniably, there is no single strategy allowing multi-scale stress transfer, and, like many biological materials [25][26][27], spider silk relies on a hierarchy of mechanisms to sustain strength and toughness across scales, from the nano-to macroscales [28]. In consideration of the fibril structure of silk, the question arises: can a little disorder-or structural heterogeneity-improve system performance?…”

“…It is well known that silk, like many biological materials, features a hierarchical structure arising from a complex assembly process [28]. The molecular geometry is defined by strands of a single, repetitive protein sequence [10], resulting in hydrogen-bonded b-sheet nanocrystals embedded in a semiamorphous protein domain [16].…”

Designing and cloning a MaSp1-based synthetic gene in binary vector for transient expression in cotton fiber

“…( Scheller et al, 2001 ) ‫دشٚسئ٥ٗ‬ ‫اص‬ ‫فبِ٣‬ ‫ٔذَ‬ ‫٤ه‬ ‫فٙىجٛر‬ ‫سبس‬ . ‫ف٥جش٢‬ ‫ٞب٢‬ ‫ص٤ؼش‬ ‫داسد‬ ‫ٔشاسج٣‬ ‫ػّؼّٝ‬ ‫ػبخشبس‬ ‫وٝ‬ ‫اػز‬ ٣ ‫د٥ٛ٘ذٞب٢‬ ‫ثب‬ ٚ ‫ضق٥ف‬ ‫ٔشوض‬ ‫دس‬ ‫ٞ٥ذسٚط٘٣‬ ‫عِٛ٣‬ ‫سغ٥٥شار‬ ‫ثٝ‬ ‫دبػخ‬ ‫دس‬ ‫سؿشٝ‬ ‫سفشبس‬ ‫سٙؾ٥ٓ‬ ‫دس‬ ‫داسد‬ ‫٘مؾ‬ ‫فٙىجٛر‬ ‫سبس‬ ( Tarakanova & Buehler, 2012 ) (Vollrath & Knight, 2001) . Motriuk-Smith et al, 2005;Rising et al, 2006 ) .…”

With great structure comes great functionality: Understanding and emulating spider silk

“…Silk is biodegradable and, unlike synthetic high-performance fibers such as Kevlar, it is extremely lightweight. [10][11][12] The mechanical performance of spider silk is retained over a large temperature range (À66 to 100°C), exhibiting particularly interesting behavior at low temperatures. At the temperature of liquid nitrogen (À196°C), silk has been shown to increase its strength by 64% relative to its strength at room temperature.…”