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Title: Isolation and characterization of novel conopeptides from Conus dalli.
Creator: Abbasi, Husam Usama., Florida Atlantic University, Mari, Frank
Abstract/Description: Conus dalli is a cone snail species that preys upon mollusks (molluscivorous) and it belongs to the same clade as the better studied Conus textile. They have different biogeographical distribution: C. dalli is restricted to the Panamic area; whereas C. textile is a widespread species found from the Red Sea to Hawaii. The venom of C. textile is an extremely complex mixture of conopeptides characterized for their very high content of modified amino acids; particularly, for their high content of...
Show moreConus dalli is a cone snail species that preys upon mollusks (molluscivorous) and it belongs to the same clade as the better studied Conus textile. They have different biogeographical distribution: C. dalli is restricted to the Panamic area; whereas C. textile is a widespread species found from the Red Sea to Hawaii. The venom of C. textile is an extremely complex mixture of conopeptides characterized for their very high content of modified amino acids; particularly, for their high content of gamma-carboxy glutamate (Gla). Therefore, it is expected that the venom of C. dalli is equally complex and it might provide us with a library of novel conopeptides. We have collected 6 specimens of C. dalli from the Pacific coast of Panama. Their venom ducts were dissected and 40 mg of crude venom were extracted. Venom was separated using SE-HPLC and RP-HPLC and several single-component fractions with unique molecular weights have been found. 1D and 2D NMR methods in conjunction with mass spectrometry techniques have been applied to the main components of the venom. Three novel conopeptides have been isolated and characterized; dal_C1011h, dal_C0910, and dal_C0805g. dal_C1011h is a 27-residue hydrophobic conotoxin that belongs to O-superfamily, dal_C0910 is a 16-residue conotoxin that belongs to M-superfamily, and dal_C0805g is a 12-residue linear conopeptide the belong to the Conorfamide family. The details on the characterization of these conopeptides along with a comparison with previous data obtained from C. textile are presented.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13214
Subject Headings: Conus, Gastropoda--Venom, Venom
Format: Document (PDF)

Title: Isolation and characterization of novel conopeptides from Conus nux.
Creator: Ramlakhan, Rani Elizabeth., Florida Atlantic University, Mari, Frank
Abstract/Description: Cone snails are marine gastropods belonging to the genus Conus that inhabit in tropical habitats throughout the world. They are predators that paralyze their prey by injection of venom, containing a complex mixture of conopeptides. The venom of cone snails has been found to be a valuable source of specific drugs for disorders ranging from stroke to chronic pain. For this work, the venom of Conus nux, a Panamic cone snail species, was extracted and analyzed. Components of the venom were...
Show moreCone snails are marine gastropods belonging to the genus Conus that inhabit in tropical habitats throughout the world. They are predators that paralyze their prey by injection of venom, containing a complex mixture of conopeptides. The venom of cone snails has been found to be a valuable source of specific drugs for disorders ranging from stroke to chronic pain. For this work, the venom of Conus nux, a Panamic cone snail species, was extracted and analyzed. Components of the venom were isolated using Size Exclusion Chromatography (SEC) and Reversed Phase High Performance Liquid Chromatography techniques. A novel conopeptide sequence, determined by Edman Degradation is reported. The arrangement of the cysteines residues within this sequence suggest that it member of the M-superfamily of conotoxins.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/12951
Subject Headings: Conus, Gastropoda--Venom, Venom
Format: Document (PDF)

Title: Discovery and structural characterization of conotoxins from the venom of vermivorous cone snails.
Creator: Dovell, Sanaz., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Cone snails are venomous marine gastropods that produce venom rich in neuroactive peptides, called conopeptides. The majority of published work on conopeptides has been from fish-hunting and mollusk-hunting cone snails. The work in this dissertation focuses on the discovery and characterization of novel conopeptides from the venom of worm-hunting cone snails. Eleven novel conopeptides have been isolated and biochemically characterized from the venom of C. nux using high performance liquid...
Show moreCone snails are venomous marine gastropods that produce venom rich in neuroactive peptides, called conopeptides. The majority of published work on conopeptides has been from fish-hunting and mollusk-hunting cone snails. The work in this dissertation focuses on the discovery and characterization of novel conopeptides from the venom of worm-hunting cone snails. Eleven novel conopeptides have been isolated and biochemically characterized from the venom of C. nux using high performance liquid chromatography for the isolation and purification, and mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy were used for the biochemical characterization of the conopeptides. Nano-NMR spectroscopy was used as a tool to elucidate the three-dimensional structures of four conotoxins using native quantities of peptide isolated from the venom of C. nux, C. villepinii, and C. regius. In addition, the sequence-specific assignments and molecular model of a conotoxin from the venom of C. flo ridanus was also completed. The first chapter reviews the known conotoxin three-dimensional structures and cystine-constrained frameworks. The second chapter presents the mini-M conotoxins isolated from the venom of C. nux. The third chapter presents the three-dimensional NMR solution structure of a mini-M conotoxin from the venom of C. regius. The fourth chapter presents the cysteine-free conopeptides isolated from the venom of C. nux; conorfamide-nux1, a RFamide-related peptide, and nux770, a short pentapeptide. The fifth chapter presents the T-superfamily conotoxins isolated from the venom of C. nux, as well as the three-dimensional solution structure of one of the T-superfamily conotoxins. The sixth chapter presents the NMR solution structure of the first conotoxin with a cysteine-stabilized helix-loop-helix fold., Finally, the seventh chapter presents the O-superfamily conotoxins isolated from the venom of C. nux, as well as the three-dimensional solution structure of one of the O- superfamily conotoxins with an unusually knotted fold. This work shows the vast structural diversity of peptides that cone snails continue to engineer.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2684305
Subject Headings: Gastropoda, Venom, Peptides, Structure, Conus, Venom
Format: Document (PDF)

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.
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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)

Title: Isolation and characterization of novel conopeptides from the marine cone snail: Conus brunneus.
Creator: Pflueger, Fred C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Cone snails are predatory marine gastropods that use venom for means of predation and defense. This venom is a complex mixture of conopeptides that selectivity binds to ion channels and receptors, giving them a wide range of potential pharmaceutical applications. Conus brunneus is a wide spread Eastern Pacific cone snail species that preys upon worms (vermivorous). Vermivorous cone snails have developed very specific biochemical strategies for the immobilization of their prey and their venom...
Show moreCone snails are predatory marine gastropods that use venom for means of predation and defense. This venom is a complex mixture of conopeptides that selectivity binds to ion channels and receptors, giving them a wide range of potential pharmaceutical applications. Conus brunneus is a wide spread Eastern Pacific cone snail species that preys upon worms (vermivorous). Vermivorous cone snails have developed very specific biochemical strategies for the immobilization of their prey and their venom has not been extensively studied to date. The main objective of this dissertation is the characterization of novel conopeptides isolated from Conus brunneus. Chapter 1 is an introduction and background on cone snails and conopeptides. Chapter 2 details the isolation and characterization of a novel P-superfamily conotoxin. Chapter 3 presents the 3D solution structure of the novel P-superfamily conotoxin. Chapter 4 details the isolation and characterization of two novel M-superfamily conotoxins. Chapter 5 covers the use of nano-NMR to characterize a novel P-superfamily conotoxin using nanomole quantities of sample. Chapter 6 is a reprint of a paper published in the Journal of the American Chemical Society in which we combined and implemented techniques developed in the previous chapters to report the presence of D-(Sd(B-Hydroxyvaline in a polypeptide chain. This dissertation contains the first reported work of a P-superfamily structure obtained directly from the crude venom therefore accurately representing native post-translational modifications. In this paper, crude cone snail venom was characterized by: high performance liquid chromatography, nuclear magnetic resonance spectroscopy, nanonuclear magnetic resonance spectroscopy, mass spectrometry, amino acid analysis, Edman degradation sequencing, and preliminary bioassays.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/3337185
Subject Headings: Gastropoda, Venom, Peptides, Structure, Conus, Venom
Format: Document (PDF)

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.
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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)

Title: New conopeptides from Conus jaspedius.
Creator: Williams, Orette St. Aubyn, Florida Atlantic University, Mari, Frank
Abstract/Description: Cone snails (genus conus) are marine gastropods of tropical waters. They capture their prey by envenomation and for this; they have evolved a highly efficient and diverse venom cocktail of proteins and peptides. This has elicited extreme interest in venom composition and their molecular targets. In this study, the venom of Conus jaspedius, a small Atlantic cone snail was extracted, venom components isolated and analyzed, by a combination of Size exclusion and High performance liquid...
Show moreCone snails (genus conus) are marine gastropods of tropical waters. They capture their prey by envenomation and for this; they have evolved a highly efficient and diverse venom cocktail of proteins and peptides. This has elicited extreme interest in venom composition and their molecular targets. In this study, the venom of Conus jaspedius, a small Atlantic cone snail was extracted, venom components isolated and analyzed, by a combination of Size exclusion and High performance liquid chromatography, NMR, Mass spectrometry and Edman sequencing. Here, four novel conopeptide sequences are reported, namely; an alpha conotoxin, a member of the A and O superfamilies and a new family.
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Date Issued: 2004
PURL: http://purl.flvc.org/fcla/dt/13303
Subject Headings: Venom, Gastropoda--Venom, Poisonous animals, Peptides--Structure
Format: Document (PDF)

Title: Novel conopeptides from Conus tessulatus.
Creator: Borges, Paula., Florida Atlantic University, Mari, Frank
Abstract/Description: Cone snails are predatory marine mollusks that utilize their peptide rich venom to capture prey, deter competitors and defend themselves. Each of the 1000 known species expresses over 100 conotoxins with little overlap between species. Most of these conotoxins selectively target a specific neuronal ion-channel or receptor. Because of their unprecedented diversity and specificity, they hold enormous potential as neuropharmacological agents, and as neuroscience research tools. In this study,...
Show moreCone snails are predatory marine mollusks that utilize their peptide rich venom to capture prey, deter competitors and defend themselves. Each of the 1000 known species expresses over 100 conotoxins with little overlap between species. Most of these conotoxins selectively target a specific neuronal ion-channel or receptor. Because of their unprecedented diversity and specificity, they hold enormous potential as neuropharmacological agents, and as neuroscience research tools. In this study, the venom of a common shallow water cone snail that thrives in the Indo-Pacific to the Panamic region, Conus tessulatus , was analyzed; conopeptide components of the venom were isolated and investigated by high performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, and automated Edman degradation sequencing. Five new peptide sequences are herein reported, among which there are three members of the M superfamily, one alpha conotoxin, and a conophan. The novel peptides comprise a partial peptide library of this particular cone.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13231
Subject Headings: Conus, Venom, Gastropoda--Venom, Peptides--Structure
Format: Document (PDF)

Title: Isolation and characterization of novel conopeptides from Conus brunneus.
Creator: Pellicier, Jalidsa., Florida Atlantic University, Mari, Frank
Abstract/Description: Cone snails are predatory marine mollusks found in the genus Conus that use a complex cocktail of peptides to capture prey and deter predators. Most of the venom components selectively target ion channels or receptors, making them invaluable tools in neurophysiological studies. In this study, the venom of Conus brunneus, a common Panamic vermivorous cone snail species, was characterized by the use of high performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, and...
Show moreCone snails are predatory marine mollusks found in the genus Conus that use a complex cocktail of peptides to capture prey and deter predators. Most of the venom components selectively target ion channels or receptors, making them invaluable tools in neurophysiological studies. In this study, the venom of Conus brunneus, a common Panamic vermivorous cone snail species, was characterized by the use of high performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, and automated Edman degradation sequencing. Three novel peptide sequences were reported: two peptides were members of the M-superfamily and one peptide was classified as an alpha-conotoxin. The disulfide connectivity of a previously isolated P-conotoxin was also determined. These peptides comprise a partial peptide library of Conus brunneus and may prove useful in numerous structural and neurological studies.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13365
Subject Headings: Conus, Gastropoda--Venom, Venom, Peptides--Structure
Format: Document (PDF)

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.
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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)

Title: Molecular characterization of the injected venom of Conus ermineus.
Creator: Rivera-Ortiz, Jose A., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Cone snails are predatory marine animals that rely on their venom components to immobilize and capture their prey. According to the type of prey preference, cone snails can be divided into three groups: vermivorous, molluscivorous and piscivorous. Conus ermineus had been identified as the only piscivorous snail of the Atlantic Ocean. Cone snail venom is a complex and rich sources of natural toxins. The majority of the components of the venom are peptidic in nature, and they act over different...
Show moreCone snails are predatory marine animals that rely on their venom components to immobilize and capture their prey. According to the type of prey preference, cone snails can be divided into three groups: vermivorous, molluscivorous and piscivorous. Conus ermineus had been identified as the only piscivorous snail of the Atlantic Ocean. Cone snail venom is a complex and rich sources of natural toxins. The majority of the components of the venom are peptidic in nature, and they act over different ionic channels and membrane receptors. Initial studies using mixture of venom collected from dissected venom ducts concluded that the venom from the same species do not exhibit unusual peptide polymorphism [Olivera, Hillyard, et al., 1995] and that the only major difference between individuals of the same species are different concentrations of the venom components [Vianna, et al., 2005]. For this study, peptides in the injected venom were collected from individual snails and characterized usin g analytical RP-HPLC for a maximum of three years. The different fractions collected were processed through capillary HPLC coupled with Q-TOF ESI-MS, and compared with analytical RP-HPLC fractions processed with MALDI-TOF MS. This study demonstrates that there is an animal-to-animal variation in the peptide components of the injected venom. The injected venom remains relatively constant over time for specific specimens in captivity. Finally, there are some peptides that had been found in all specimens both by MALDI-TOF MS and by ESI-MS. In this study, these peptides are called "molecular fingerprint" peptides. Based on matches of their derived masses to those predicted by published cDNA sequences, nine novel peptides were putatively identified. This study establishes that variations due to enzymatic posttranslational modification are omitted when we consider only information extrapolated from cDNA., The results of this study support the idea of the existence of a novel regulatory mechaism to expressed specific venom peptides for injection into the prey.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3333310
Subject Headings: Gastropoda, Venom, Peptides, Structure, Coastal ecology
Format: Document (PDF)

Title: Neuroprotection from induced glutamate excitotoxicity by Conus brunneus conopeptides in a stroke-related model.
Creator: Crouch, Rebecca A., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: Cone snails are carnivorous marine mollusks, utilizing their neuropeptide-rich venom for prey capture. The venom of Conus brunneus, a wide-spread Eastern Pacific vermivore, has not been extensively studied. In the current work, peptides from the dissected venom were characterized and tested using preliminary bioassays. Six peptides (A-F) were isolated and tested. Three peptide identities were determined by comparison with previously reported data: bru9a (A), bru3a (F), and an a-conotoxin (E)....
Show moreCone snails are carnivorous marine mollusks, utilizing their neuropeptide-rich venom for prey capture. The venom of Conus brunneus, a wide-spread Eastern Pacific vermivore, has not been extensively studied. In the current work, peptides from the dissected venom were characterized and tested using preliminary bioassays. Six peptides (A-F) were isolated and tested. Three peptide identities were determined by comparison with previously reported data: bru9a (A), bru3a (F), and an a-conotoxin (E). Preliminary screening in a stroke-related model of induced glutamate excitotoxicity in primary neuronal cells and PC12 cell cultures indicated potential neuroprotective activity of peptide fractions A, D, and F. Further testing is necessary to determine and verify structure, activity, target, and mechanism of action of the promising peptides from C. brunneus, which may prove effective neuropharmacological agents to treat stroke.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362331
Subject Headings: Gastropoda, Venom, Therapeutic use, Peptides, Structure, Neuroprotective agents, Central nervous system, Diseases, Treatment
Format: Document (PDF)

Title: Isolation and characterization of neuroactive peptides from the venom of cone snail species.
Creator: Cano, Herminsul, Florida Atlantic University, Mari, Frank
Abstract/Description: The mam objective of the work described in this thesis is isolation and characterization of novel neuroactive peptides from the venom of cone snail species. The first section is an introduction about cone snails. The first chapter is dedicated to the analysis of the milked venom obtained from three different specimens of C. ermineus which is the only fish-hunter cone snail from the east Atlantic region. MALDI-TOF mass spectrometry analysis of two specimens showed an identical profile with all...
Show moreThe mam objective of the work described in this thesis is isolation and characterization of novel neuroactive peptides from the venom of cone snail species. The first section is an introduction about cone snails. The first chapter is dedicated to the analysis of the milked venom obtained from three different specimens of C. ermineus which is the only fish-hunter cone snail from the east Atlantic region. MALDI-TOF mass spectrometry analysis of two specimens showed an identical profile with all components of the venom being novel conopeptides. The third specimen showed a mass spectrometry profile with molecular weights corresponding to already reported conotoxins plus one additional new conopeptide. Ten new conotoxins were isolated from C. ermineus; seven of them have sequences corresponding to A-superfamily of conotoxins, specifically a-conotoxins family. Six of these seven conotoxins are the first a4/4 conotoxins isolated from the milked venom from any fish-hunter cone snail specimens; the other one is a a4/7 conotoxin similar sequence to the already reported a-EI from C. ermineus. Two more conotoxins that belong to the 0-superfamily have the same amino acid sequence with the only difference being a hydroxyproline residue instead of a proline at position 21 of the sequence. In the second chapter, four specimens of C. purpurascens, the only fish-hunter of the Eastern Pacific region were analyzed. One of the specimens was sacrified and the crude venom was dissected-out of the venom duct. For the three remaining live specimens the venom was obtained by the "milking" procedure. Mass spectrometry profiles were compared between dissected and milked venom and between milked venom from different specimens. Analysis showed both similarities and differences in the profiles of the dissected and the three milked venoms. A comparison of the three milked venoms found some differences. This analysis showed that one specimen expressed two isomorphs of a putative a4/4-conotoxin; the only difference was the presence of proline instead of hydroxyproline at position seven in the amino acid sequence. These a4/4-conotoxins are the second report of this sub-class of conotoxin from the milked venom of cone snails and they have sequence homology to the a4/4 conotoxins isolated from C. ermineus. The analysis of the MALDI-TOF MS/MS spectra of the Leu-contryphan-P conopeptide from C. purpurascens revealed that conotoxins with a single disulfide bond in the sequence behave as a linear peptide in the mass spectrometry experiment exhibiting a good fragmentation pattern. Using this information by comparing the MS/MS spectra we were able to identify L-contryphan-P conopeptide lacking the first Gly residue in the sequence. In the third chapter, three conotoxins with sequence homology to the omega-superfamily were isolated from the crude dissected venom of the worm-hunter cone snail C. vexillum. The precursor of one of these conotoxins was already characterized by another research group. Analysis and comparison of this precursor with already known precursor allowed us to hypothesize that these conotoxins were ro-conotoxins. Two of the three conotoxins have the same amino acid sequence with hydroxyproline instead a proline in the structure. These conotoxins were the first ones isolated from the venom duct of these cone snail species. Several conotoxins had been reported from C. vexillum but they were isolated using eDNA cloning techniques. Chapter four shows the analysis of the worm-hunter cone snail C. pseudoarantius crude venom. Eight novel conotoxins were isolated from the pooled duct dissected venom from different specimens. The first was a a4/3-conotoxin with a carboxyglutamate residue present at position one in the sequence. Five more conotoxins with conotoxin frameworks and sequences similar to M-superfamily of conotoxins were also found; additionally, two more novel conotoxins with sequence homology to o-conotoxins from the S-superfamily were isolated. All the above conotoxins were analyzed by comparison of their structures against sequences of known conotoxins. All 23 conotoxins found in this research are novel conopeptides isolated from cone snail specimens. Future work on the activity these conotoxins will be important in the search for possible drugs in treatment of many diseases.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/12185
Subject Headings: Peptides--Structure, Gastropoda--Venom, Conus, Mass spectrometry--Analysis
Format: Document (PDF)

Venom (11)	+ -
Conus (8)	+ -
Gastropoda--Venom (6)	+ -
Gastropoda (4)	+ -
Peptides (4)	+ -

Peptides--Structure (4)	+ -
Structure (4)	+ -
Peptides -- Structure (3)	+ -
Drosophila melanogaster (2)	+ -
Gastropoda -- Venom (2)	+ -
Central nervous system (1)	+ -
Coastal ecology (1)	+ -
Conidae -- Environmental aspects (1)	+ -
Diseases (1)	+ -
Gastropoda -- venom (1)	+ -
Mass spectrometry--Analysis (1)	+ -
Neuroprotective agents (1)	+ -
Poisonous animals (1)	+ -
Therapeutic use (1)	+ -
Treatment (1)	+ -
Venum (1)	+ -

Florida Atlantic University (10)	+ -
Mari, Frank (9)	+ -
Charles E. Schmidt College of Science (7)	+ -
Department of Chemistry and Biochemistry (7)	+ -
Abbasi, Husam Usama. (1)	+ -

Borges, Paula. (1)	+ -
Cano, Herminsul (1)	+ -
Crouch, Rebecca A. (1)	+ -
Dovell, Sanaz. (1)	+ -
Heghinian, Mari D. (1)	+ -
Pak, Adriana (1)	+ -
Pellicier, Jalidsa. (1)	+ -
Pflueger, Fred C. (1)	+ -
Ramlakhan, Rani Elizabeth. (1)	+ -
Rivera-Ortiz, Jose A. (1)	+ -
Rodriguez, Alena (1)	+ -
Williams, Orette St. Aubyn (1)	+ -

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