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Characterization of Disulfide Constrained Natural Peptides

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Date Issued:
2018
Abstract/Description:
The use of peptide drugs has gained popularity recently. Peptides are attractive drug targets due to their high specificity and potency towards their biological targets. A drawback for peptide drugs is a lack of stability for oral delivery. Two classes of disulfide-rich peptides, conotoxins and cyclotides, have been shown to have higher stability than linear peptides thanks to their disulfide connectivity. Conotoxins are present in the venom of cone snails, a carnivorous marine mollusk that preys upon fish, worms, or other mollusks. Conotoxins are promising drugs leads with great prospects in the treatment of diseases and disorders such as chronic pain, multiple sclerosis and Parkinson’s and Alzheimer’s diseases. Cyclotides, which are cyclic cysteine knot containing peptides, isolated from the Violaceae (violet), Rubiaceae (coffee), and Cucurbitaceae (cucurbit) families and they have a wide range of biological activities, such as anti-HIV, uterotonic, and antimicrobial. P-superfamily framework IX conotoxins (C-C- C-CXC- C) contain the same cysteine framework, homologous sequences, and similar 3D structures to cyclotides. The knot containing conotoxins have been identified in several Conus species, but this work focuses on those from Conus brunneus, Conus purpurascens, and Conus gloriamaris. The cysteine knot motif of cyclotides and P-superfamily conotoxins is characterized by a cyclic backbone and six-conserved cysteine residues that form the three-disulfide bridges of the “knot”. This motif provides cyclotides and conotoxins with superior stability against thermal, chemical, and enzymatic degradation; marking them as potential frameworks for peptide drug delivery. Presented are details on the isolation of conotoxins and cyclotides, from Viola tricolor, and the characterization of their activity in the well-characterized Drosophila melanogaster giant fiber system (GFS) neuronal circuit, which contains GAP, acetylcholine, and glutamate synapses. The transcriptomes of two Conus brunneus specimens were assembled and mined for P-superfamily framework IX conotoxins. Eleven mature P-superfamily framework IX conotoxins were identified in the crude venom.
Title: Characterization of Disulfide Constrained Natural Peptides.
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Name(s): Hoggard, Mickelene F., author
Cudic, Mare, Thesis advisor
Florida Atlantic University, Degree grantor
Charles E. Schmidt College of Science
Department of Chemistry and Biochemistry
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2018
Date Issued: 2018
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 113 p.
Language(s): English
Abstract/Description: The use of peptide drugs has gained popularity recently. Peptides are attractive drug targets due to their high specificity and potency towards their biological targets. A drawback for peptide drugs is a lack of stability for oral delivery. Two classes of disulfide-rich peptides, conotoxins and cyclotides, have been shown to have higher stability than linear peptides thanks to their disulfide connectivity. Conotoxins are present in the venom of cone snails, a carnivorous marine mollusk that preys upon fish, worms, or other mollusks. Conotoxins are promising drugs leads with great prospects in the treatment of diseases and disorders such as chronic pain, multiple sclerosis and Parkinson’s and Alzheimer’s diseases. Cyclotides, which are cyclic cysteine knot containing peptides, isolated from the Violaceae (violet), Rubiaceae (coffee), and Cucurbitaceae (cucurbit) families and they have a wide range of biological activities, such as anti-HIV, uterotonic, and antimicrobial. P-superfamily framework IX conotoxins (C-C- C-CXC- C) contain the same cysteine framework, homologous sequences, and similar 3D structures to cyclotides. The knot containing conotoxins have been identified in several Conus species, but this work focuses on those from Conus brunneus, Conus purpurascens, and Conus gloriamaris. The cysteine knot motif of cyclotides and P-superfamily conotoxins is characterized by a cyclic backbone and six-conserved cysteine residues that form the three-disulfide bridges of the “knot”. This motif provides cyclotides and conotoxins with superior stability against thermal, chemical, and enzymatic degradation; marking them as potential frameworks for peptide drug delivery. Presented are details on the isolation of conotoxins and cyclotides, from Viola tricolor, and the characterization of their activity in the well-characterized Drosophila melanogaster giant fiber system (GFS) neuronal circuit, which contains GAP, acetylcholine, and glutamate synapses. The transcriptomes of two Conus brunneus specimens were assembled and mined for P-superfamily framework IX conotoxins. Eleven mature P-superfamily framework IX conotoxins were identified in the crude venom.
Identifier: FA00005955 (IID)
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2018.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Peptide drugs
Cyclotides
Conotoxins
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00005955
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
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Owner Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.