1,721,172 research outputs found
Recent structure-activity studies of the peptide hormone urotensin-II, a potent vasoconstrictor
No full text
Putative odorant-binding protein in antennae and legs of Carausius morosus (Insecta, Phasmatodea)
No full textA 19 kDa protein has been purified by gel filtration and anion-exchange chromatography from the antennae of Carausius morosus. Its amino terminal amino acid sequence shows significant similarity (30% identity) with another putative odorant-binding protein, the so called OS-D protein isolated from the antennae of Drosophila melanogaster; only 20% of its amino acids are shared with some members of Lepidoptera pheromone-binding proteins, Polyclonal antibodies, raised against a synthetic amino terminal peptide cross-react with 19 kDa band in the legs extracts, but not with soluble proteins from other parts of the body, The amino terminal sequence of this protein, purified from the legs was identical with that of the antennal protein
Urotensin-II Receptor Peptide Agonists
No full textUrotensin II (U-II) has been known for over 30 years as an important teleost fish hormone, but only recently has it been recognized as the endogenous ligand of a new human G-protein-coupled receptor (GPCR) homologous to the GPR14 orphan receptor from rat. Human U-II was found to be a potent vasoconstrictor, widely distributed in human tissues, possibly contributing to several human cardiovascular diseases. It thus has become a major target of medicinal chemistry research. The common structural feature of U-II peptides from different species is the C-terminal portion, characterized by the disulfide bridged cyclic hexapeptide Cys-Phe-Trp-Lys-Tyr-Cys. The few structure-activity relationship studies reported to date attributed a critical role to this portion, with the Trp-Lys-Tyr motif appearing as the key determinant of U-II bioactivity. Consequently, this shorter cyclic peptide was used as a template for the development of several synthetic analogues, among which a superagonist, termed P5U: H-Asp-cyclo(Pen-Phe-Trp-Lys-Tyr-Cys)-Val-OH. Conformational studies confirmed the important role of hU-II C-terminal cyclic portion, enabling the development of 3D pharmacophore models. These findings should lead to the design of new, potent and selective analogues, acting as agonist or antagonist at the human U-II receptor, finally contributing to a deeper comprehension of the (patho)physiological significance of this peptid
Facile reduction of peptide oxime endothelin antagonist during trialkylsilane/TFA cleavage after solid-phase synthesis
No full textWe describe a new solid-phase strategy for the selective reduction of the C=N bond in peptide oximes using a trialkylsilane in trifluoroacetic acid. The reduction is performed directly on the resin-bound peptide, with concomitant cleavage of the peptide from the resin and deblocking of protected side chains. © 1996 ESCOM Science Publishers B.V
Peptide-based immunoassays: a challenge for high performance diagnostics & prognostics of autoimmune diseases
No full textAutoimmune diseases are considered now as a plague. In fact some
autoimmune diseases previously considered rare are actually increasing
their frequency because of an earlier diagnosis (e.g. celiac disease).
Possibly also an environmental factor (bacterial and/or viral infection) should contribute to autoimmune diseases. The idea we have been
investigating for years and more recently proposed by others, is that
aberrant post-translational modifi cations, i.e. glycosylation, deimination
etc., create neoantigens triggering autoantibodies. This could explain
why proteins (both recombinant and isolated), components of target
organs or tissues, are failing. Anyway, it is evident that one single
biomarker will never enable to reach successful diagnostic & prognostic
tools. On the contrary, synthetic peptides specifi cally modifi ed (with
sugars, citrulline, lipoyl moieties, etc.) are interesting tools to fi shing
out of patients’ sera these autoantibodies. We have recently reported that
this can be effi ciently done following a “Chemical Reverse Approach”
1.. We successfully applied this strategy in the development of the
fi rst Multiple Sclerosis Antigenic Probe [MSAP]: an N-glucosylated
peptide characterised by a -hairpin structure exposing at the best the
minimal epitope Asn(-Glc) involved in antibody recognition (2). A
wider application of our SAP is obtained by its citrullinatation and/or
galactosylation (3) useful for rheumatoid arthritis or lipoylation for
investigating primary biliary cirrhosis
Urotensin-II Receptor Antagonists
No full textUrotensin-II (U-II) is a "somatostatin-like" cyclic neuropeptide which was originally isolated from goby fish urophysis, and subsequently identified in other species, including man. The interest in human U-II (hU-II) has grown enormously in the last few years, following the identification of a specific human receptor (formerly identified as the GPR14/SENR orphan receptor), now referred to as UT receptor. The U-II/UT system seems to play an important role in cardiovascular functions. hU-II vasoconstrictive potency is reported to be an order of magnitude greater than that of endothelin-1 (ET-1), which would make it the most potent mammalian vasoconstrictor identified to date. hU-II also exerts potent inotropic effects in the human heart in vitro. On the basis of its spectrum of activities, hU-II has been suggested to modulate cardiovascular homeostasis and possibly to be involved in certain cardiovascular pathologies. Central nervous effects of U-II have also been described, in particular, intracerebroventricular administration promotes anxiogenic-like behaviors in rodents. Furthermore, UT receptor overexpression has been observed in some tumor cell lines. Therefore, specific and selective UT receptor antagonists provide useful tools for investigating the (patho)physiological role(s) of the U-II/UT receptor system. In this review we aim to provide an overview of the research in the area of UT receptor antagonists as well as the progress in understanding the role of the U-II/UT system in human (patho)physiology
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
