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(1 - 11 of 11)
- Title
- Variability in the venom of Conus regius.
- Creator
- Uribe-Benninghoff, Alejandro., Florida Atlantic University, Hartmann, James X., Mari, Frank
- Abstract/Description
-
The venom of two different geographical populations of Conus regius has been isolated and characterized. Comparisons between the chromatographic profiles of the venom of these two populations exhibited similarities and differences among the venom's constituents. MALDI-TOF and PCR analysis techniques ratified the differences present in the venom of both populations. It is postulated that these differences could reflect the rapid adaptive nature of cone snails in an actual stage of speciation....
Show moreThe venom of two different geographical populations of Conus regius has been isolated and characterized. Comparisons between the chromatographic profiles of the venom of these two populations exhibited similarities and differences among the venom's constituents. MALDI-TOF and PCR analysis techniques ratified the differences present in the venom of both populations. It is postulated that these differences could reflect the rapid adaptive nature of cone snails in an actual stage of speciation. Molecular weights of the venom's constituents were compared with those of patented conopeptides in the Swiss Protein Database. Results of this comparison indicated that a number of the peptides isolated for both of the populations of C. regius had the same molecular weight as other patented conopeptides. In combination with the PCR analysis of these conopeptides, it has been proposed that some of the venom constituents of the venom of C. regius could have pharmacological applications for vertebrate systems.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15746
- Subject Headings
- Conus--Venom
- Format
- Document (PDF)
- 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.
Show less - 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.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12951
- Subject Headings
- Conus, Gastropoda--Venom, Venom
- Format
- Document (PDF)
- Title
- Conserved toxin framework between cone snail and violet plant.
- Creator
- Hoggard, Mickelene F., Mari, Frank, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361932
- Subject Headings
- Conotoxins, Snails, Conus, Cyclotides, Viola tricolor
- 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.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2684305
- Subject Headings
- Gastropoda, Venom, Peptides, Structure, Conus, 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.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/3337185
- Subject Headings
- Gastropoda, Venom, Peptides, Structure, Conus, Venom
- 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.
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)
- 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.
Show less - 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.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13365
- Subject Headings
- Conus, Gastropoda--Venom, Venom, Peptides--Structure
- Format
- Document (PDF)
- Title
- Three-dimensional structure of the alpha-conotoxin EI determined by proton NMR spectroscopy.
- Creator
- Franco, Aldo, Florida Atlantic University, Mari, Frank
- Abstract/Description
-
The alpha-conotoxin EI is an 18-residue peptide (RDOCCYHPTCNMSNPQIC; 4-10, 5-18) isolated from the venom of Conus ermineus. This peptide targets the nicotinic acetylcholine receptor (nAChR) found in mammalian skeletal muscle and the electric organ of Torpedo. 2D-NMR methods and dynamical simulated annealing protocols have been used to determine the 3D structure of EI. 133 NOE-derived distances were used to produce 13 structures with minimum energy that complied with the NOE restraints. The...
Show moreThe alpha-conotoxin EI is an 18-residue peptide (RDOCCYHPTCNMSNPQIC; 4-10, 5-18) isolated from the venom of Conus ermineus. This peptide targets the nicotinic acetylcholine receptor (nAChR) found in mammalian skeletal muscle and the electric organ of Torpedo. 2D-NMR methods and dynamical simulated annealing protocols have been used to determine the 3D structure of EI. 133 NOE-derived distances were used to produce 13 structures with minimum energy that complied with the NOE restraints. The structure of EI is characterized by a helical loop between T9 and M12 that is stabilized by the C4-C10 disulfide bond and turns involving C4-C5 and N14-P15. The overall fold of EI is similar to that of other alpha4/7 conotoxins (PnIA/B, MII, EpI). However, unlike these other alpha4/7 conotoxins, EI targets the muscular type nAChR. The differences in selectivity can be attributed to the surface charge distribution among these alpha4/7 conotoxins.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15609
- Subject Headings
- Conus--Venom, Peptides--Structure, Nuclear magnetic resonance spectroscopy
- 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.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12185
- Subject Headings
- Peptides--Structure, Gastropoda--Venom, Conus, Mass spectrometry--Analysis
- Format
- Document (PDF)
