Characterization of a family of cysteine rich proteins and development of a MaSp1 derived miniature fibroin

<p>Spider silk displays a unique balance of high tensile strength and extensibility, making it one of the toughest materials on the planet. Dragline silk, also known as the lifeline of the spider, represents one of the best studied fiber types and many labs are attempting to produce synthetic dragline silk fibers for commercial applications. In these studies, we develop a minifibroin for expression studies in bacteria. Using recombinant DNA methodology and protein expression studies, we develop a natural minifibroin that contains the highly conserved N- and C-terminal domains, along with several internal block repeats of MaSp1. We also characterize a family of small cysteine-rich proteins (CRPs) and demonstrate that these factors are present within the spinning dope of the major ampullate gland using MS analysis. Biochemical studies and characterization of one of the family members, CRP1, demonstrate that this factor can self-polymerize into higher molecular weight complexes under oxidizing conditions, but can be converted into a monomeric species under reducing conditions. Self-polymerization of CRP1 is also shown to be independent of pH and salt concentration, two important chemical cues that help fibroin aggregation. Overall, our data demonstrate that the polymerization state of CRP1 is dependent upon redox state, suggesting that the redox environment during fiber extrusion may help regulate the oligomerization of CRP molecules during dragline silk production.</p>

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Thesis - Pacific Access Restricted

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2014

Author dc:creator

• Chuang, Tyler Casey

Contributors dc:contributor

• Craig Vierra

• Molecular biology
• Biochemistry
• Materials science
• Pure sciences
• Biological sciences
• Applied sciences
• Black widow
• Cysteine
• Dragline
• Fibroin
• Silk
• Biology

Licence

• http://rightsstatements.org/vocab/InC/1.0/

Identifier

9781321386158

OAI identifier oai:identifier

oai:scholarlycommons.pacific.edu:uop_etds-1179