41 resultados para NATRIURETIC PEPTIDE LEVELS


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Amphibian skin contains rich bradykinin-related peptides, but the mode of biosynthesis of these peptides is unknown. In the present study, a novel bradykinin-related peptide, termed bombinakinin M, was purified from skin secretions of the Chinese red bell

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Amphibian skin is a rich resource of antimicrobial peptides like maximins and maximins H from toad Bombina maxima. A novel cDNA clone encoding a precursor protein that comprises maximin 3 and a novel peptide. named maximin H5. was isolated from a skin cDNA library of B. maxima. The predicted primary structure of maximin H5 is ILGPVLGLVSDTLDDVLGIL-NH2,. Containing three aspartate residues and no basic amino acid residues. maximin H5 is characterized by an anionic property. Different from cationic maximin H peptides. only Gram-positive strain Staphylococcus aureus was sensitive to maximin H5. while the other bacteria] and fungal strains tested ere resistant to it. The presence of metal ions. like Zn2+ and Mg2+, did not increase its antimicrobial potency. Maximin H5 represents the first example of potential anionic antimicrobial peptides from amphibians, The results provide the first evidence that. together kith cationic antimicrobial peptides. anionic antimicrobial peptides may also exist naturally as part of the innate defense system. (C), 2002 Elsevier Science (USA). All rights reserved.

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A novel bombesin-related peptide was isolated from skin secretions of Chinese red belly toad Bombina maxima. Its primary structure was established as pGlu-Lys-Lys-Pro-Pro-Arg-Pro-Pro-Gln-Trp-Ala-Val-Gly-His-Phe-Met-NH2. The amino-terminal (N-terminal) 8-residue segment comprising four prolines and three basic residues is extensively different from bombesins from other Bombina species. The peptide was thus named proline rich bombesin (PR-bombesin). PR-bumbesin was found to elicit concentration-dependent contractile effects in the rat stomach strip, with both increased potency and intrinsic activity as compared with those of [Leu(13)]bombesin. Analysis of different bombesin cDNA structures revealed that an 8 to 14- nucleotide fragment replacement in the peptide coding region (TGGGGAAT in the cDNAs of multiple bombesin forms from Bombina orientalis and CACCCCGGCCACCC in the cDNA of PR-bombesin) resulted in an unusual Pro-Pro-Arg-Pro-Pro motif in the N-terminal part of PR-bombesin. (C) 2002 Elsevier Science Inc. All rights reserved.

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An opioid peptide, which shares similarity with mammalian hemorphins, has been identified from the synganglia (central nervous system) of the hard tick, Amblyomma testindiarium. Its primary sequence was established as LVVYPWTKM that contains a tetrapeptide sequence Tyr-Pro-Trp-Thr of hemorphin-like opioid peptides. By hot-plate bioassay, the purified peptide and synthetic peptide displayed dose-related antinociceptive effect in mice, as observed for other hemorphin-like opioid peptides. This is the first opioid peptide identified from ticks. Ticks may utilize the opioid peptide in their strategy to escape host immuno-surveillance as well as in inhibiting responses directed against themselves. (c) 2004 Elsevier Inc. All rights reserved.

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A novel antimicrobial peptide named as ixosin was isolated from the salivary glands of the hard tick, Ixodes sinensis, by gel filtration, ion exchange chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Its amino acid sequen

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Several algesic agents including bradykinin and tachykinin have been identified from skin secretions of amphibians. They may act in defensive roles against aggressors. In this study, a novel peptide named Amolos with an amino acid sequence of FLPIVGAKL an

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A novel 28-amino acid peptide, termed bombinakinin-GAP, was purified and characterized from skin secretions of the toad Bombina maxima. Its primary structure was established as DMYEIKQYKTAHGRPPICAPGEQCPIWV-NH2, in which two cysteines form a disulfide bond. A FASTA search of SWISS-PROT databank detected a 32% sequence identity between the sequences of the peptide and a segment of rat cocaine- and amphetamine-regulated transcript (CART). Intracerebroventricular (i.c.v.) administration of the peptide induced a significant decrease in food intake in rats, suggesting that it played a role in the control of feeding by brain. Analysis of its cDNA structure revealed that this peptide is coexpressed with bombinakinin M, a bradykinin-related peptide from the same toad. Bombinakinin-GAP appears to be the first example of a novel class of bioactive peptides from amphibian skin, which may be implicated in feeding behavior. (C) 2003 Elsevier Science Inc. All rights reserved.

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An antimicrobial peptide named odorranain-HP was identified from skin secretions of the diskless odorous frog, Odorrana grahami. It is composed of 23 amino acids with an amino acid sequence of GLLRASSVWGRKYYVDLAGCAKA. By BLAST search, odorranain-HP had si

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Despite the evolutional distance between wasp and amphibian, vespid chemotactic peptide (VCP), an important component of wasp venom, are found sharing remarkable similarities with the temporin antimicrobial peptides (AMPs) from Ranid frog, Amolops loloens

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Amphibian skin is a rich resource of antimicrobial peptides, like maximins and maximin Hs from frog Bombina maxima. Novel cDNA clones encoding a precursor protein, which comprises a novel maximin peptide (maximin 9) and reported maximin H3, were isolated from two constructed skin cDNA libraries of B. maxima. The predicted primary structure of maximin 9 is GIGRKFLGGVKTTFRCGVKDFASKHLY-NH2. A surprising substitution is at position 16, with a free cysteine in maximin 9 rather than usual conserved glycine in other reported maximins. Maximin 9, the homodimer form and its Cys(16) to Gly(16) mutant were synthesized and their antimicrobial activities were evaluated. Unlike previously reported maximin 3, the tested bacterial and fungal strains were resistant to maximin 9, its homodimer and the Cys(16) to Gly(16) mutant (with MICs > 100 mu M). On the other hand, interestingly, while eight clinical Mollicutes strains were generally resistant to maximin 9 homodimer and its Cys(16) to Gly(16) mutant, most of them are sensitive to maximin 9 at a peptide concentration of 30 mu M, especially in the presence of dithiothreitol. These results indicate that the presence of a reactive Cys residue in maximin 9 is important for its antimycoplasma activity. The diversity of antimicrobial peptide cDNA structures encountered in B. maxima skin cDNA libraries and the antimicrobial specificity differences of the peptides may reflect well the species' adaptation to the unique microbial environments. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.