Date of Degree

10-2014

Document Type

Dissertation

Degree Name

Ph.D.

Program

Biochemistry

Advisor(s)

Mande Holford

Subject Categories

Biochemistry

Keywords

genetics, terebrid, Venom

Abstract

Unravelling the complex mixture of neuropeptides produced by the terebrid venom duct holds the promise of discovering tomorrow's therapeutics. Cone snails have already demonstrated the potential found in the venom of these unusual marine organisms, through the commercial approval of drugs for pain and other indications. Terebrids, as the sister family to the cone snails, have been much less investigated, but have a species richness that makes them very attractive in the search for novel neuropeptides. The venomics research described in this work encompasses the first comprehensive characterization of the terebrid venom duct transcriptomes of two species, Cinguloterebra anilis and Terebra subulata. De novo assembly and analysis were performed using next generation sequencing technology and state of the art bioinformatics tools to identify the cocktail of peptides, teretoxins, produced by the venom duct. These disulfide rich peptides often show a remarkable specificity for subtypes of ion channels and ligand-gated receptors, giving them therapeutic potential, but they are only available in vanishingly small amounts from the natural source. As a result, identification of teretoxins using next generation sequencing is a prelude to synthesizing them in sufficient quantities to test for bioactivity. Here recombinant expression and solid phase peptide synthesis have both been utilized for the synthesis of four different teretoxins, with a special focus on recombinant synthesis to design a reproducible strategy for synthesizing disulfide rich peptides greater than 40 amino acids in length. Preliminary characterization of bioactivity was performed by injecting synthesized toxin into the polychaete N. virens. A teretoxin identified from Terebra guttata, Tg77, has produced promising results in this assay, with repeated trials showing the effects of uncoordinated movement and rigid paralysis. Further testing on Tg77 and other teretoxins will be carried forward, with an evident need for high throughput assays to provide an efficient means for the testing of novel compounds with a variety of potential molecular targets.

Included in

Biochemistry Commons

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