Search results for "tryptophan"
showing 10 items of 141 documents
Tryptophan-Containing Dual Neuroprotective Peptides: Prolyl Endopeptidase Inhibition and Caenorhabditis elegans Protection from β-Amyloid Peptide Tox…
2018
Neuroprotective peptides represent an attractive pharmacological strategy for the prevention or treatment of age-related diseases, for which there are currently few effective therapies. Lactoferrin (LF)-derived peptides (PKHs) and a set of six rationally-designed tryptophan (W)-containing heptapeptides (PACEIs) were characterized as prolyl endopeptidase (PEP) inhibitors, and their effect on β-amyloid peptide (Aβ) toxicity in a Caenorhabditis elegans model of Alzheimer’s disease (AD) was evaluated. Two LF-derived sequences, PKH8 and PKH11, sharing a W at the C-terminal end, and the six PACEI heptapeptides (PACEI48L to PACEI53L) exhibited significant in vitro PEP inhibition. The inhibitory pe…
Isocratic high-performance liquid chromatographic determination of tryptophan in infant formulas.
1996
The application to infant formulas of a method for tryptophan determination by isocratic HPLC with UV detection at 254 nm, after derivatization with phenyl isothiocyanate, was studied. Protein was hydrolysed by barium hydroxide at 120 degrees C for 8 h, followed by derivatization with phenyl isothiocyanate, HPLC and UV detection at 254 nm. The optimum chromatographic conditions (pH, ionic strength of elution solvent and eluent ratio) were established. The analytical parameters (linearity, precision, accuracy of derivatization and limits of detection and quantification) were determined. The values obtained demonstrated that the method is useful for determining the tryptophan content of infan…
Serotonergic polymorphisms in patients suffering from alcoholism, anxiety disorders and narcolepsy.
2001
Abstract 1. Alterations in the serotonergic neurotransmission have been frequently described for patients suffering from alcoholism, anxiety disorders and narcolepsy. 2. The authors tested for association of the 5-HT2A receptor polymorphism (T102C) and the intron 7 tryptophan hydroxylase (TPH) polymorphism (A218C) among 176 alcohol dependent patients, 35 patients with panic disorder, 50 patients with generalized anxiety disorder, 55 patients with narcolepsy and 87 healthy controls. 3. Allele and genotype frequencies of the 5-HT2A receptor polymorphism (T102C), the intron 7 TPH polymorphism (A218C) were almost similar between the patients suffering from alcohol dependence, panic disorder, ge…
Omphalotins E-I, Five Oxidatively Modified Nematicidal Cyclopeptides fromOmphalotus olearius
2009
Omphalotins E–I, oxidatively modified cyclic dodecapeptides, were isolated from mycelial extracts of the basidiomycete Omphalotus olearius, and their structures were determined by NMR spectroscopic and MS methods. Four of the five omphalotins contained an unprecedented N-hydroxylated tricyclic tryptophan derivative. All compounds exhibited strong and selective nematicidal activity against the plant pathogen Meloidogyne incognita with LD90 values between 2 and 5 μg mL–1. Cytotoxic activities were not detected up to 50 μg mL–1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Epidemiology of intensive care unit-acquired sepsis in Italy: Results of the SPIN-UTI network
2018
Background. Sepsis is the major cause of mortality from any infectious disease worldwide. Sepsis may be the result of a healthcare associated infection (HAI): the most frequent adverse events during care delivery especially in Intensive Care Units (ICUs). The main aim of the present study was to describe the epidemiology of ICU-acquired sepsis and related outcomes among patients enrolled in the framework of the Italian Nosocomial Infections Surveillance in ICUs - SPIN-UTI project. Study design. Prospective multicenter study. Methods. The SPIN-UTI network adopted the European protocols for patient-based HAI surveillance. Results. During the five editions of the SPIN-UTI project, from 2008 to…
Effects of Environmental Lighting and Tryptophan Devoid Diet on the Rat Vaginal Cycle
1998
Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous dar…
Conformational changes involved in thermal aggregation processes of bovine serum albumin
2003
We report a kinetic study on thermal aggregation process of the model protein bovine serum albumin (BSA) in low concentration regime. Aim of this study is to provide information on relationship between conformational changes and initial step of aggregation. The experimental approach is based on steady-state fluorescence spectra of the two tryptophans located in two different domains, in way to study conformational changes in the surrounding of these residues. We also follow emission spectra of Fluorescein-5-Maleimide dye bound to the single free cysteine of BSA. Complementary information on the extent of aggregation and on the structural changes is obtained by Rayleigh scattering and circul…
Cryptic Secondary Metabolites from the Sponge-Associated Fungus Aspergillus ochraceus
2019
The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4&ndash
Serratia symbiotica from the aphid Cinara cedri: a missing link from facultative to obligate insect endosymbiont.
2011
The genome sequencing of Buchnera aphidicola BCc from the aphid Cinara cedri, which is the smallest known Buchnera genome, revealed that this bacterium had lost its symbiotic role, as it was not able to synthesize tryptophan and riboflavin. Moreover, the biosynthesis of tryptophan is shared with the endosymbiont Serratia symbiotica SCc, which coexists with B. aphidicola in this aphid. The whole-genome sequencing of S. symbiotica SCc reveals an endosymbiont in a stage of genome reduction that is closer to an obligate endosymbiont, such as B. aphidicola from Acyrthosiphon pisum, than to another S. symbiotica, which is a facultative endosymbiont in this aphid, and presents much less gene decay…
Photosensibilisierte Oxidation von Lysozym bei Verschiedenen Wellenlängen
1974
The photooxidation of lysozyme in the presence of methylene blue, riboflavine, and bengal rose at differentpH values and wavelengths was studied. Monochromatic irradiation at shorter wavelengths (345 and 365 nm) is - in contrast to visible light - characterized by higher energy yields and lower oxygen consumption. This behavior suggests that the mechanism of photooxidation depends on the wavelength. The specific destruction of amino acid residues is also wavelength-dependent. Using visible light of 448 and 621 nm for riboflavine and methylene blue, respectively, we have confirmed the selective destruction of histidine and tryptophan atpH 7,0. The energy yield for the destruction of tryptoph…