Current Search:  info:fedora/islandora:personCModel (x) » Arabic (x) » Department of Chemistry and Biochemistry (x) » Peptides -- Structure (x)

View All Items

  • CSV Spreadsheet
(1 - 3 of 3)
Discovery and biological characterization of conotoxins from the venom of Conus Brunneus in Drosophila Melanogaster
Title
Discovery and biological characterization of conotoxins from the venom of Conus Brunneus in Drosophila Melanogaster.
Creator
Heghinian, Mari D., Mari, Frank, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description
Cone snails are venomous marine predators whose venom is a complex mixture of modified peptides (conopeptides). Conopeptides have direct specificity towards voltage- and ligand-gated ion channels and G-protein coupled receptors. More specifically, alpha conotoxins target nicotinic acetylcholine receptors (nAChR) and are of great interest as probes for different nAChR subtypes involved in a broad range of neurological function. Typically, the amount of peptide provided directly from the cone...
Show moreCone snails are venomous marine predators whose venom is a complex mixture of modified peptides (conopeptides). Conopeptides have direct specificity towards voltage- and ligand-gated ion channels and G-protein coupled receptors. More specifically, alpha conotoxins target nicotinic acetylcholine receptors (nAChR) and are of great interest as probes for different nAChR subtypes involved in a broad range of neurological function. Typically, the amount of peptide provided directly from the cone snails (from either dissected or “milked” venom) is minimal, thus hindering the wide use of bioassay-guided approaches for compound discovery. Biochemical-based approaches for discovery by means of identification and characterization of venom components can be used due to their compatibility with the small quantities of cone snail venom available; however, no direct assessment of the bioactivity can be gleaned from these approaches. Therefore, newly discovered conotoxins must be acquired synthetically, which can be difficult due to their complicated folding motifs. The ability to test small quantities of peptide for bioactivity during the purification process can lead to the discovery of novel components using more direct approaches. Presented here is the description of use of an effective method of bioassay-guided fractionation for the discovery of novel alpha conotoxins as well as further biological characterization of other known alpha conotoxins. This method requires minimal amounts of sample and evaluates, via in vivo electrophysiological measurements, the effect of conotoxins on the functional outputs of a well-characterized neuronal circuit in Drosophila melanogaster known as the giant fiber system. Our approach uses reversed-phase HPLC fractions from venom dissected from the ducts of Conus brunneus in addition to synthetic alpha conotoxins. Fractions were individually tested for activity, re-fractionated, and re-tested to narrow down the compound responsible for activity. A novel alpha conotoxin, bru1b, was discovered via the aforementioned approach. It has been fully characterized in the giant fiber system through the use of mutant flies, as well as tested in Xenopus oocytes expressing nicotinic acetylcholine channels and against the acetylcholine binding protein. Other well-known alpha conotoxins have also been characterized in the giant fiber system.
Show less
Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004122, http://purl.flvc.org/fau/fd/FA00004122
Subject Headings
Drosophila melanogaster, Gastropoda -- venom, Peptides -- Structure, Venom
Format
Document (PDF)
Isocation and characterization of conotoxins from the venom of Conus Planorbis and Conus Ferrugineus
Title
Isocation and characterization of conotoxins from the venom of Conus Planorbis and Conus Ferrugineus.
Creator
Pak, Adriana, Mari, Frank, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description
The venom of marine gastropods belonging to the genus Conus has yielded numerous structurally and functionally diverse peptidic components. The increase variety of bioactive peptides identified in cone snail venoms is the product of the variety of molecular adaptations taken by Conus species in evolving neuroactive molecules to suit their diverse biological purposes. Toxins from cone snails are classified into two major groups. One group consists of disulfide-rich peptides commonly termed...
Show moreThe venom of marine gastropods belonging to the genus Conus has yielded numerous structurally and functionally diverse peptidic components. The increase variety of bioactive peptides identified in cone snail venoms is the product of the variety of molecular adaptations taken by Conus species in evolving neuroactive molecules to suit their diverse biological purposes. Toxins from cone snails are classified into two major groups. One group consists of disulfide-rich peptides commonly termed conotoxins; the second group comprises peptides with only one disulfide bond or none. In this work, we present the discovery and characterization from the marine snails C. planorbis and C. ferrugineus. Both species are commonly found in the Indo-Pacific region and are very similar and is not distinguishable by size and shape of the shell. Novel P and T-Supefamiles were found in both species along with small linear peptides with have a high frequency of tyrosine residues. Each chapter contains a detailed look at the discovery process for the isolation and characterization of C. planorbis and C. ferrugineus. At discussion part, we also compared the peptides isolated in this work with other peptides from the literature.
Show less
Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004146, http://purl.flvc.org/fau/fd/FA00004146
Subject Headings
Conus, Gastropoda -- Venom, Peptides -- Structure, Venum
Format
Document (PDF)
Peptidomic analysis and characterization of the venom from Conus purpurascens
Title
Peptidomic analysis and characterization of the venom from Conus purpurascens.
Creator
Rodriguez, Alena, Mari, Frank, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description
The venom of cone snails is a potent cocktail of peptides, proteins, and other small molecules. Several of the peptides (conopeptides and conotoxins) target ion channels and receptors and have proven useful as biochemical probes or pharmaceutical leads. In this study, the venom of a fish-hunting cone snail, Conus purpurascens was analyzed for intraspecific variability; α-conotoxins from the venom were isolated by high performance liquid chromatography, identified by mass spectrometry and...
Show moreThe venom of cone snails is a potent cocktail of peptides, proteins, and other small molecules. Several of the peptides (conopeptides and conotoxins) target ion channels and receptors and have proven useful as biochemical probes or pharmaceutical leads. In this study, the venom of a fish-hunting cone snail, Conus purpurascens was analyzed for intraspecific variability; α-conotoxins from the venom were isolated by high performance liquid chromatography, identified by mass spectrometry and nuclear magnetic resonance, and tested in a electrophysiological assay in Drosophila melanogaster; the effects of diet change on venom composition was investigated. It has been determined that each specimen of C. purpurascens expresses a distinct venom, resulting in the expression of more than 5,000 unique conopeptides across the species. α- conotoxin PIA was shown to inhibit the Dα7 nicotinic acetylcholine receptor.
Show less
Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004403, http://purl.flvc.org/fau/fd/FA00004403
Subject Headings
Conidae -- Environmental aspects, Drosophila melanogaster, Gastropoda -- Venom, Peptides -- Structure, Venom
Format
Document (PDF)