Patrick Dennis (Advisor), Madhavi Kadakia (Committee Member), Yong-jie Xu (Committee Member)
Master of Science (MS)
The unique protein-based structure of Sucker Ring Teeth (SRT) of cephalopods have spurned research into the molecular design, physical characteristics, functionality and mechanical properties to explore biomimetic engineering and biochemical potential for eventual industrial production. Previous research has elucidated the potential for scientific and industrial exploitation. However, much of the previous research focused on the most abundant protein isoform of the sucker ring teeth, suckerin-19 (also known as suckerin-39) from the Jumbo or Humboldt Squid (Dosidicus Gigas). There is little known about the characteristics of the other 37 protein isoforms of Sucker Ring Teeth. Although the other isoforms have similar modular repeats in the primary and secondary structures, the other isoforms are smaller and may provide some additional clues into the biochemical characteristics of the suckerin genes. Of the 37 protein isoforms, the suckerin-12 isoform displayed some sequence and modular similarities to suckerin-19 that warranted further evaluation. The procedures and techniques used to study suckerin-12 focused on the expression and purification techniques, mechanical and structural analysis, and fine-tuning strategies for future functionalization. Experiments were performed to evaluate protein isoform suckerin-12 as a candidate to provide a suitable biopolymer for development of highly durable and strong biomaterials that rival other suckerin isoforms and may provide some insight into protein functionality in both dry and wet environments. By mimicking post-transcriptional cellular processes in an aqueous and dry environment, suckerin-12 displayed special physical and chemical characteristics to those seen in suckerin-19. Specifically, the procedures used to form testable suckerin-12 based materials via di-Tyrosine cross-linking required alternate methods than the ruthenium-based cross-linking observed in suckerin-19 studies. This study presents a method that increases the stability of the suckerin-12 protein structure through enzymatically cross-linking di-tyrosine to create sclerotized hydrogel structures. Hydrogen-bonding and induced hydrophobic and non-polar interactions are important in suckerin protein aggregation and protein solubility in various solvents. Utilizing salting-in and salting out techniques with Hofmeister series anions allowed fine-tuning and protein structural and conformational manipulation through fine-tuning of concentrations, pH, and ionic strengths.
Department or Program
Department of Biochemistry and Molecular Biology
Year Degree Awarded
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