Disulfide Crosslinked Hydrogels Made From the Hydra Stinging Cell Protein, Minicollagen-1.

Sanaz Farajollahi,Marquise G Crosby,Joseph M Slocik,Meredith N Silberstein,Lawrence F Drummy,Anthony T Pelton,Rajesh R Naik,Steven J Yang,Maneesh K Gupta,Cheri M Hampton,Patrick B Dennis

doi:10.3389/fchem.2019.00950

Sanaz Farajollahi, Marquise G Crosby + Show 9 more

Open Access

https://doi.org/10.3389/fchem.2019.00950

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Abstract

Minicollagens from cnidarian nematocysts are attractive potential building blocks for the creation of strong, lightweight and tough polymeric materials with the potential for dynamic and reconfigurable crosslinking to modulate functionality. In this study, the Hydra magnipapillata minicollagen-1 isoform was recombinantly expressed in bacteria, and a high throughput purification protocol was developed to generate milligram levels of pure protein without column chromatography. The resulting minicollagen-1 preparation demonstrated spectral properties similar to those observed with collagen and polyproline sequences as well as the ability to self-assemble into oriented fibers and bundles. Photo-crosslinking with Ru(II) was used to create robust hydrogels that were analyzed by mechanical testing. Interestingly, the minicollagen-1 hydrogels could be dissolved with reducing agents, indicating that ruthenium-mediated photo-crosslinking was able to induce disulfide metathesis to create the hydrogels. Together, this work is an important first step in creating minicollagen-based materials whose properties can be manipulated through static and reconfigurable post-translational modifications.

Highlights

Marine organisms have proven to be a rich resource for the discovery of biomaterials with unique properties that hold promise for the creation of new advanced materials, such as strong, lightweight polymers, adhesives and biophotonic structures (Crookes et al, 2004; Degtyar et al, 2014; Petrone et al, 2015)
The H. magnipapillata minicollagen-1 has been well-studied and represents the canonical form of the minicollagen family with a central collagen-like set of 14 Gly-X-Y repeats immediately flanked at both ends with polyproline regions and cysteine rich domains at both the amino and carboxyl termini (Figure 1A)
In minicollagen-1, prolines occupy the Y position of 86% of the three amino acid repeats and at both the X and Y positions in 36% of the repeats (Supplementary Figure 1). Both hexa-histidine tagged and untagged versions of minicollagen-1 were created for bacterial expression in E. coli, where the hexa-histidine tagged form of minicollagen-1 was initially used for screening of bacterial expression

Summary

Introduction

Marine organisms have proven to be a rich resource for the discovery of biomaterials with unique properties that hold promise for the creation of new advanced materials, such as strong, lightweight polymers, adhesives and biophotonic structures (Crookes et al, 2004; Degtyar et al, 2014; Petrone et al, 2015). The nematocyst undergoes explosive release of a stylet within 700 ns, generating an acceleration of 5,400,000 x g (Nuchter et al, 2006). The rapid deployment of the piercing structure is enabled due to the high osmotic pressure (150 bars) stored in the nematocyst capsule (Weber, 1989), which is generated by the accumulation of polyglutamic acid and ions within the capsule (Weber, 1990). In addition to the stylet, a tubule is everted from the nematocyst for the delivery of venom (Ozbek et al, 2009). The nematocyst capsule is composed of outer and inner walls, where the function of the outer wall is proposed to direct organization and assembly of the inner wall (Engel et al, 2002)

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