1,721,236 research outputs found
Natural and synthetic peptides in the cardiovascular diseases: An update on diagnostic and therapeutic potentials
No full textSeveral peptides play an important role in physiological and pathological conditions into the cardiovascular system. In addition to well-known vasoactive agents such as angiotensin II, endothelin, serotonin or natriuretic peptides, the vasoconstrictor Urotensin-II (Uro-II) and the vasodilators Urocortins (UCNs) and Adrenomedullin (AM) have been implicated in the control of vascular tone and blood pressure as well as in cardiovascular disease states including congestive heart failure, atherosclerosis, coronary artery disease, and pulmonary and systemic hypertension. Therefore these peptides, together with their receptors, become important therapeutic targets in cardiovascular diseases (CVDs). Circulating levels of these agents in the blood are markedly modified in patients with specific CVDs compared with those in healthy patients, becoming also potential biomarkers for these pathologies. This review will provide an overview of current knowledge about the physiological roles of Uro-II, UCN and AM in the cardiovascular system and their implications in cardiovascular diseases. It will further focus on the structural modifications carried out on original peptide sequences in the search of analogues with improved physiochemical properties as well as in the delivery methods. Finally, we have overviewed the possible application of these peptides and/or their precursors as biomarkers of CVDs
Recent structure-activity studies of the peptide hormone urotensin-II, a potent vasoconstrictor
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A cystine-based dual chemosensor for fluorescent-colorimetric detection of CN− and fluorescent detection of Fe3+ in aqueous media: Synthesis, spectroscopic, and DFT studies
No full textA new dual-responsive chiral cystine based chemosensor, Cys(cou)2, has been designed and characterized by 1H NMR, 13C NMR, FT-IR, UV–vis as well as elemental analysis. This sensor exhibited an excellent response towards Fe3+ and CN− with high selectivity and sensitivity by fluorescence turn-off mechanism. The binding mode of Cys(cou)2 with Fe3+, and CN− was confirmed by ESI-MS, 1H NMR, and fluorescence titration and also quantum chemical calculation. These results showed that the stoichiometric ratio of Cys(cou)2-Fe3+ and Cys(cou)2-CN is 1:1 and 1:3 in DMSO/Tris aqueous buffer (1:1, v/v), respectively. The linear relationship of the Stern-Volmer plot illustrates the static quenching mechanism at different concentrations. The detection limit (LOD) and binding constant (Ka) for Fe3+ and CN− are 0.029 μM, 1.28 × 104 and 0.51 μM, 9.94 × 106, respectively. Moreover, Cys(cou)2 can act as a colorimetric sensor for CN− in DMSO with the color change from colorless to yellow
New melanocortin peptides useful as medicament against Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, Candida glabrata or Candida krusei
No full textNOVELTY - Melanocortin peptides (I) are new.
USE - (I) are useful as: antimicrobial medicament against Staphylococcus aureus or Pseudomonas aeruginosa; or candidacidal medicament against Candida albicans, Candida glabrata and Candida krusei (all claimed).
ADVANTAGE - (I) have less side effects, which are tolerable to patients, stable, safer and easier to administer.
DETAILED DESCRIPTION - Melanocortin peptides of formula (W1-A1-A2-A3-A4-X-A5-A6-A7-Y1) (I) are new. An INDEPENDENT CLAIM is also included for a pharmaceutical preparation comprising at least one of the peptide
Unraveling the Active Conformation of Urotensin II
No full textUrotensin II (U-II) is a disulfide-bridged undecapeptide recently identified as the ligand of an orphan G-protein-coupled receptor. Human U-II (H-Glu-Thr-Pro-Asp-cyclo[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH) has been described as the most potent vasoconstrictor compound identified to date. With the aim of elucidating the active conformation of hU-II, we have performed a spectroscopic analysis of hU-II minimal active fragment hU-II(4-11) in different environmental conditions. The analysis indicated that hU-II(4-11) was highly structured in the anisotropic membrane mimetic SDS solution, showing a type II′ β-turn structure, which is almost unprecedented for L-amino acid peptides. Micelle bound structure of hU-II(4-11) was then compared with those of four synthetic analogues recently synthesized in our lab, bearing modified Cys residues at position 5 and/or position 10 and characterized by different levels of agonist activity. The structures of the active compounds were found to be very similar to that of hU-II(4-11), while a barely active compound does not show any propensity to β-turn formation. Furthermore, distances among putative pharmacophoric points in the structures of the active compounds obtained in SDS solution are in good agreement with those found in a recently described non-peptide agonist of the hU-II receptor. A type II′ β-turn structure was already found for the somatostatin analogue octreotide. On the basis of the similarity of the primary and 3D structures of U-II and somatostatin analogues and on the basis of the sequence homology between the GPR14/UT-II receptor and members of the somatostatin receptor family, a common evolutionary pathway for the signal transmission system activated by these peptide can be hypothesized
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