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Michael J Conlon - One of the best experts on this subject based on the ideXlab platform.
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the alyteserins two families of antimicrobial peptides from the skin secretions of the midwife toad alytes obstetricans alytidae
Peptides, 2009Co-Authors: Michael J Conlon, Anni Demandt, Per F. Nielsen, Hubert Vaudry, Jérôme Leprince, Douglas C. WoodhamsAbstract:Abstract Two families of structurally related C-terminally α-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH 2 ) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH 2 ) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu.NH 2 ) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC = 25 μM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC = 50 μM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC 50 > 100 μM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity.
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tachykinins substance p and neuropeptide γ from the brains of the pallid sturgeon scaphirhynchus albus and the paddlefish polyodon spathula acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract A peptide with substance P-like immunoreactivity was isolated from extracts of the brains of the pallid sturgeon, Scaphirhynchus albus and the North American paddlefish, Polyodon spathula. The primary structure of the peptide (Lys-Pro-Lys-Pro-His-Gln-Phe-Phe-Gly-Leu-Met.NH 2 ) is the same in both species and contains 2 amino acid substitutions (Arg 1 → Lys and Gln 5 → His) compared with human substance P and 1 substitution (Arg 3 → Lys) compared with substance P from the trout (Teleostei). Scyliorhinin I, a tachykinin previously isolated from an extract of sturgeon intestine, was not detected in either brain extract. A peptide with neurokinin A-like immunoreactivity (Ser-Ser-Ala-Asn-Arg-Gln-Ile-Thr-Gly-Lys 10 Arg-Gln-Lys-Ile-Asn-Ser-Phe-Val-Gly-Leu 20 Met.NH 2 ) was isolated from sturgeon brain and contains 10 amino acid substitutions compared with human neuropeptide γ (a specific product of the posttranslational processing of γ-preprotachykinin A) but only 4 substitutions compared with trout neuropeptide γ. It was not possible to obtain the paddlefish neurokinin A-related peptide in pure form. The structural similarity between the sturgeon and the trout tachykinins supports the hypothesis that the Acipenseriformes (sturgeons and paddlefish) represent the sister group of the Neopterygii (gars, bowfin, and teleosts).
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purification and characterization of galanin and scyliorhinin i from the hybrid sturgeon scaphirhynchus platorynchus scaphirhynchus albus acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract The sturgeons (order Acipenseriformes) are extant representatives of a group of ancient Actinopterygian (ray-finned) fish. Galanin and scyliorhinin I (a tachykinin with limited structural similarity to mammalian substance P) have been isolated from an extract of the gastrointestinal tract of a sturgeon (an F1 hybrid between the shovelnose sturgeon, Scaphirhynchus platorynchus, and the pallid sturgeon, Scaphirhynchus albus ). The primary structure of sturgeon galanin (Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu 10 -Leu-Gly-Pro-His-Ala-Val-Asp-Gly-His-Arg 20 -Ser-Leu-Ser-Asp-Lys-His-Gly-Leu-Pro·NH 2 ) contains only two amino acid substitutions (Ser 23 → Asn and Pro 29 → Ala) compared with galanin from the bowfin, Amia calva (Amiiformes), but five amino acid substitutions compared with galanin from the trout (Teleostei). Similarly, the sturgeon tachykinin (Ser-Lys-Tyr-His-Gln-Phe-Tyr-Gly-Leu-Met·NH 2 ) contains only one amino acid substitution (Tyr 3 → Ser) compared with scyliorhinin I previously isolated from bowfin stomach but five amino acid substitutions compared with trout substance P. The data support the hypothesis that the Acipenseriformes and the basal Neopterygians (gars and bowfin) share a close phylogenetic relationship.
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primary structure of insulin from the african lungfish protopterus annectens
General and Comparative Endocrinology, 1997Co-Authors: Michael J Conlon, James E Platz, Per F. Nielsen, Hubert Vaudry, Mauro VallarinoAbstract:Among the extant Sarcopterygii, the interrelationship between the Dipnoi (lungfishes), Actinistia (coelacanths), and Tetrapoda (tetrapods) is controversial. Insulin has been purified from an extract of the pancreas of the African lungfishProtopterus annectensand its primary structure established as A-chain, Gly–Ile–Val–Glu–Gln–Cys–Cys–His–Lys–Pro10–Cys–Ser–Leu– Tyr –Glu–Leu–Glu–Asn–Tyr–Cys20–Asn–Val–Pro; and B-chain, Ala–Val–Leu–Asn–Gln–His–Leu–Cys–Gly–Ser10–His–Leu–Val– Glu– Ala–Leu–Tyr–Leu–Val–Cys20–Ala–Asp–Asn–Gly–Phe– Phe–Tyr–Lys–Pro–Ser30–Gly. Lungfish insulin contains unusual structural features, such as the dipeptide extension to the C-terminus of the A-chain and the substitution Arg → Asn at position B-23 in the putative receptor binding region of insulin, which may be expected to influence appreciably its biological potency relative to mammalian insulins. Lungfish insulin also contains amino acid substitutions such as Gly → Ala at position B-21, Glu → Asp at position B-22, and a Lys → Ser residue at position B-30, previously found in insulins from amphibia. This observation is consistent with paleontological data suggesting that lungfish and amphibia share a close phylogenetic relationship.
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primary structures of the bombesin like neuropeptides in frog brain show that bombesin is not the amphibian gastrin releasing peptide
Biochemical and Biophysical Research Communications, 1991Co-Authors: Michael J Conlon, Finbarr Oharte, Hubert VaudryAbstract:Abstract Peptides displaying gastrin-releasing peptide/bombesin-like immunoreactivity were isolated in pure form from an extract of the brain of the European green frog, Rana ridibunda . The primary structure of the more abundant peptide was established as: Gly-Ser-His-Trp-Ala-Val-Gly-His-Leu-Met.NH 2 . This sequence shows one substitution (Ser for Asn) compared with mammalian gastrin-releasing peptide (18–27) (neuromedin C). The extract also contained gastrin-releasing peptide but bombesin was absent. The data indicate that bombesin is not the amphibian counterpart of gastrin-releasing peptide.
Hubert Vaudry - One of the best experts on this subject based on the ideXlab platform.
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the alyteserins two families of antimicrobial peptides from the skin secretions of the midwife toad alytes obstetricans alytidae
Peptides, 2009Co-Authors: Michael J Conlon, Anni Demandt, Per F. Nielsen, Hubert Vaudry, Jérôme Leprince, Douglas C. WoodhamsAbstract:Abstract Two families of structurally related C-terminally α-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH 2 ) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH 2 ) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu.NH 2 ) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC = 25 μM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC = 50 μM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC 50 > 100 μM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity.
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primary structure of insulin from the african lungfish protopterus annectens
General and Comparative Endocrinology, 1997Co-Authors: Michael J Conlon, James E Platz, Per F. Nielsen, Hubert Vaudry, Mauro VallarinoAbstract:Among the extant Sarcopterygii, the interrelationship between the Dipnoi (lungfishes), Actinistia (coelacanths), and Tetrapoda (tetrapods) is controversial. Insulin has been purified from an extract of the pancreas of the African lungfishProtopterus annectensand its primary structure established as A-chain, Gly–Ile–Val–Glu–Gln–Cys–Cys–His–Lys–Pro10–Cys–Ser–Leu– Tyr –Glu–Leu–Glu–Asn–Tyr–Cys20–Asn–Val–Pro; and B-chain, Ala–Val–Leu–Asn–Gln–His–Leu–Cys–Gly–Ser10–His–Leu–Val– Glu– Ala–Leu–Tyr–Leu–Val–Cys20–Ala–Asp–Asn–Gly–Phe– Phe–Tyr–Lys–Pro–Ser30–Gly. Lungfish insulin contains unusual structural features, such as the dipeptide extension to the C-terminus of the A-chain and the substitution Arg → Asn at position B-23 in the putative receptor binding region of insulin, which may be expected to influence appreciably its biological potency relative to mammalian insulins. Lungfish insulin also contains amino acid substitutions such as Gly → Ala at position B-21, Glu → Asp at position B-22, and a Lys → Ser residue at position B-30, previously found in insulins from amphibia. This observation is consistent with paleontological data suggesting that lungfish and amphibia share a close phylogenetic relationship.
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primary structures of the bombesin like neuropeptides in frog brain show that bombesin is not the amphibian gastrin releasing peptide
Biochemical and Biophysical Research Communications, 1991Co-Authors: Michael J Conlon, Finbarr Oharte, Hubert VaudryAbstract:Abstract Peptides displaying gastrin-releasing peptide/bombesin-like immunoreactivity were isolated in pure form from an extract of the brain of the European green frog, Rana ridibunda . The primary structure of the more abundant peptide was established as: Gly-Ser-His-Trp-Ala-Val-Gly-His-Leu-Met.NH 2 . This sequence shows one substitution (Ser for Asn) compared with mammalian gastrin-releasing peptide (18–27) (neuromedin C). The extract also contained gastrin-releasing peptide but bombesin was absent. The data indicate that bombesin is not the amphibian counterpart of gastrin-releasing peptide.
Per F. Nielsen - One of the best experts on this subject based on the ideXlab platform.
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the alyteserins two families of antimicrobial peptides from the skin secretions of the midwife toad alytes obstetricans alytidae
Peptides, 2009Co-Authors: Michael J Conlon, Anni Demandt, Per F. Nielsen, Hubert Vaudry, Jérôme Leprince, Douglas C. WoodhamsAbstract:Abstract Two families of structurally related C-terminally α-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH 2 ) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH 2 ) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu.NH 2 ) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC = 25 μM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC = 50 μM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC 50 > 100 μM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity.
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tachykinins substance p and neuropeptide γ from the brains of the pallid sturgeon scaphirhynchus albus and the paddlefish polyodon spathula acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract A peptide with substance P-like immunoreactivity was isolated from extracts of the brains of the pallid sturgeon, Scaphirhynchus albus and the North American paddlefish, Polyodon spathula. The primary structure of the peptide (Lys-Pro-Lys-Pro-His-Gln-Phe-Phe-Gly-Leu-Met.NH 2 ) is the same in both species and contains 2 amino acid substitutions (Arg 1 → Lys and Gln 5 → His) compared with human substance P and 1 substitution (Arg 3 → Lys) compared with substance P from the trout (Teleostei). Scyliorhinin I, a tachykinin previously isolated from an extract of sturgeon intestine, was not detected in either brain extract. A peptide with neurokinin A-like immunoreactivity (Ser-Ser-Ala-Asn-Arg-Gln-Ile-Thr-Gly-Lys 10 Arg-Gln-Lys-Ile-Asn-Ser-Phe-Val-Gly-Leu 20 Met.NH 2 ) was isolated from sturgeon brain and contains 10 amino acid substitutions compared with human neuropeptide γ (a specific product of the posttranslational processing of γ-preprotachykinin A) but only 4 substitutions compared with trout neuropeptide γ. It was not possible to obtain the paddlefish neurokinin A-related peptide in pure form. The structural similarity between the sturgeon and the trout tachykinins supports the hypothesis that the Acipenseriformes (sturgeons and paddlefish) represent the sister group of the Neopterygii (gars, bowfin, and teleosts).
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purification and characterization of galanin and scyliorhinin i from the hybrid sturgeon scaphirhynchus platorynchus scaphirhynchus albus acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract The sturgeons (order Acipenseriformes) are extant representatives of a group of ancient Actinopterygian (ray-finned) fish. Galanin and scyliorhinin I (a tachykinin with limited structural similarity to mammalian substance P) have been isolated from an extract of the gastrointestinal tract of a sturgeon (an F1 hybrid between the shovelnose sturgeon, Scaphirhynchus platorynchus, and the pallid sturgeon, Scaphirhynchus albus ). The primary structure of sturgeon galanin (Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu 10 -Leu-Gly-Pro-His-Ala-Val-Asp-Gly-His-Arg 20 -Ser-Leu-Ser-Asp-Lys-His-Gly-Leu-Pro·NH 2 ) contains only two amino acid substitutions (Ser 23 → Asn and Pro 29 → Ala) compared with galanin from the bowfin, Amia calva (Amiiformes), but five amino acid substitutions compared with galanin from the trout (Teleostei). Similarly, the sturgeon tachykinin (Ser-Lys-Tyr-His-Gln-Phe-Tyr-Gly-Leu-Met·NH 2 ) contains only one amino acid substitution (Tyr 3 → Ser) compared with scyliorhinin I previously isolated from bowfin stomach but five amino acid substitutions compared with trout substance P. The data support the hypothesis that the Acipenseriformes and the basal Neopterygians (gars and bowfin) share a close phylogenetic relationship.
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primary structure of insulin from the african lungfish protopterus annectens
General and Comparative Endocrinology, 1997Co-Authors: Michael J Conlon, James E Platz, Per F. Nielsen, Hubert Vaudry, Mauro VallarinoAbstract:Among the extant Sarcopterygii, the interrelationship between the Dipnoi (lungfishes), Actinistia (coelacanths), and Tetrapoda (tetrapods) is controversial. Insulin has been purified from an extract of the pancreas of the African lungfishProtopterus annectensand its primary structure established as A-chain, Gly–Ile–Val–Glu–Gln–Cys–Cys–His–Lys–Pro10–Cys–Ser–Leu– Tyr –Glu–Leu–Glu–Asn–Tyr–Cys20–Asn–Val–Pro; and B-chain, Ala–Val–Leu–Asn–Gln–His–Leu–Cys–Gly–Ser10–His–Leu–Val– Glu– Ala–Leu–Tyr–Leu–Val–Cys20–Ala–Asp–Asn–Gly–Phe– Phe–Tyr–Lys–Pro–Ser30–Gly. Lungfish insulin contains unusual structural features, such as the dipeptide extension to the C-terminus of the A-chain and the substitution Arg → Asn at position B-23 in the putative receptor binding region of insulin, which may be expected to influence appreciably its biological potency relative to mammalian insulins. Lungfish insulin also contains amino acid substitutions such as Gly → Ala at position B-21, Glu → Asp at position B-22, and a Lys → Ser residue at position B-30, previously found in insulins from amphibia. This observation is consistent with paleontological data suggesting that lungfish and amphibia share a close phylogenetic relationship.
Douglas C. Woodhams - One of the best experts on this subject based on the ideXlab platform.
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the alyteserins two families of antimicrobial peptides from the skin secretions of the midwife toad alytes obstetricans alytidae
Peptides, 2009Co-Authors: Michael J Conlon, Anni Demandt, Per F. Nielsen, Hubert Vaudry, Jérôme Leprince, Douglas C. WoodhamsAbstract:Abstract Two families of structurally related C-terminally α-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH 2 ) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH 2 ) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu.NH 2 ) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC = 25 μM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC = 50 μM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC 50 > 100 μM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity.
Yuqi Wang - One of the best experts on this subject based on the ideXlab platform.
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tachykinins substance p and neuropeptide γ from the brains of the pallid sturgeon scaphirhynchus albus and the paddlefish polyodon spathula acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract A peptide with substance P-like immunoreactivity was isolated from extracts of the brains of the pallid sturgeon, Scaphirhynchus albus and the North American paddlefish, Polyodon spathula. The primary structure of the peptide (Lys-Pro-Lys-Pro-His-Gln-Phe-Phe-Gly-Leu-Met.NH 2 ) is the same in both species and contains 2 amino acid substitutions (Arg 1 → Lys and Gln 5 → His) compared with human substance P and 1 substitution (Arg 3 → Lys) compared with substance P from the trout (Teleostei). Scyliorhinin I, a tachykinin previously isolated from an extract of sturgeon intestine, was not detected in either brain extract. A peptide with neurokinin A-like immunoreactivity (Ser-Ser-Ala-Asn-Arg-Gln-Ile-Thr-Gly-Lys 10 Arg-Gln-Lys-Ile-Asn-Ser-Phe-Val-Gly-Leu 20 Met.NH 2 ) was isolated from sturgeon brain and contains 10 amino acid substitutions compared with human neuropeptide γ (a specific product of the posttranslational processing of γ-preprotachykinin A) but only 4 substitutions compared with trout neuropeptide γ. It was not possible to obtain the paddlefish neurokinin A-related peptide in pure form. The structural similarity between the sturgeon and the trout tachykinins supports the hypothesis that the Acipenseriformes (sturgeons and paddlefish) represent the sister group of the Neopterygii (gars, bowfin, and teleosts).
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purification and characterization of galanin and scyliorhinin i from the hybrid sturgeon scaphirhynchus platorynchus scaphirhynchus albus acipenseriformes
General and Comparative Endocrinology, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Bruce A Barton, Michael J ConlonAbstract:Abstract The sturgeons (order Acipenseriformes) are extant representatives of a group of ancient Actinopterygian (ray-finned) fish. Galanin and scyliorhinin I (a tachykinin with limited structural similarity to mammalian substance P) have been isolated from an extract of the gastrointestinal tract of a sturgeon (an F1 hybrid between the shovelnose sturgeon, Scaphirhynchus platorynchus, and the pallid sturgeon, Scaphirhynchus albus ). The primary structure of sturgeon galanin (Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu 10 -Leu-Gly-Pro-His-Ala-Val-Asp-Gly-His-Arg 20 -Ser-Leu-Ser-Asp-Lys-His-Gly-Leu-Pro·NH 2 ) contains only two amino acid substitutions (Ser 23 → Asn and Pro 29 → Ala) compared with galanin from the bowfin, Amia calva (Amiiformes), but five amino acid substitutions compared with galanin from the trout (Teleostei). Similarly, the sturgeon tachykinin (Ser-Lys-Tyr-His-Gln-Phe-Tyr-Gly-Leu-Met·NH 2 ) contains only one amino acid substitution (Tyr 3 → Ser) compared with scyliorhinin I previously isolated from bowfin stomach but five amino acid substitutions compared with trout substance P. The data support the hypothesis that the Acipenseriformes and the basal Neopterygians (gars and bowfin) share a close phylogenetic relationship.
