Search results for "peptide"
showing 10 items of 4589 documents
Role of secondary metabolites in the biocontrol activity of Pseudomonas corrugata and Pseudomonas mediterranea
2017
In this study, the Pseudomonas corrugata strain CFBP 5454 and the P. mediterranea strain CFBP 5447 were shown to produce diffusible compounds that inhibit the in vitro growth of plant pathogenic fungi and bacteria and antifungal volatile compounds. In addition, both bacterial strains were found to produce cyanide. Mutant derivatives in LuxR transcriptional regulators, i.e. P. corrugata GL2 (pcoR mutant) and GLRFIA (rfiA mutant), and P. mediterranea PSMER (pmeR mutant) and PSRFIA (rfiA mutant) impaired in cyclic lipopeptide (CLP) production, showed a diffusible compound-mediated reduced activity, depending on the biocontrol strain, challenge microorganism and culture medium. The volatile com…
Yeast trehalases: Two enzymes, one catalytic mission
2016
Abstract Background Trehalose is a non-reducing disaccharide highly conserved throughout evolution. In yeasts, trehalose hydrolysis is confined to the enzyme trehalase, an α-glucosidase specific for trehalose as sole substrate. Two kinds of trehalase activity exist in yeasts: neutral and acid enzymes. Scope of the review This review makes a comparative survey of the main biochemical and genetic parameters, regulatory systems, tridimensional structure and catalytic mechanism of the two yeast trehalases. Major conclusions The yeast neutral and acid trehalases display sharp differences in biochemical features (optimum pH, Mr or amino acid sequence) physiological roles, subcellular location (cy…
Marinomonas spartinae sp. nov., a novel species with plant-beneficial properties.
2016
Two strains of Gram-stain-negative, chemo-organotrophic, aerobic and halophilic gammaproteobacteria, isolated from within the stem and roots of Spartina maritima in salt marshes from the south Atlantic Spanish coast, were found to represent a novel species in the genus Marinomonas through phylogenetic analysis of their 16S rRNA genes and phenotypic characterization. 16S rRNA gene sequences of the two strains shared < 96.2 % similarity with other Marinomonas species, with Marimonas alcarazii being the most similar in sequence. They required sodium ions for growth, were able to thrive at low (4 °C) temperatures and at salinities of 12–15 %, were unable to hydrolyse any tested macromolecule ex…
Loss-of-Function Mutations in UNC45A Cause a Syndrome Associating Cholestasis, Diarrhea, Impaired Hearing, and Bone Fragility
2018
International audience; Despite the rapid discovery of genes for rare genetic disorders, we continue to encounter individuals presenting with syndromic manifestations. Here, we have studied four affected people in three families presenting with cholestasis, congenital diarrhea, impaired hearing, and bone fragility. Whole-exome sequencing of all affected individuals and their parents identified biallelic mutations in Unc-45 Myosin Chaperone A (UNC45A) as a likely driver for this disorder. Subsequent in vitro and in vivo functional studies of the candidate gene indicated a loss-of-function paradigm, wherein mutations attenuated or abolished protein activity with concomitant defects in gut dev…
A lipidomic cell-based assay for studying drug-induced phospholipidosis and steatosis
2017
Phospholipidosis and steatosis are two toxic effects, which course with overaccumulation of different classes of lipids in the liver. MS-based lipidomics has become a powerful tool for the comprehensive determination of lipids. LC-MS lipid profiling of HepG2 cells is proposed as an in vitro assay to study and anticipate phospholipidosis and steatosis. Cells with and without pre-incubation with a mixture of free fatty acids (FFA) (i.e., oleic and palmitic) were exposed to a set of well-known steatogenic and phospholipidogenic compounds. The use of FFA pre-loading accelerated the accumulation of phospholipids thus leading to a better discrimination of phospholipidosis, and magnified the lipid…
Nutraceuticals as an Important Part of Combination Therapy in Dyslipidaemia
2017
Several risk factors such as abnormality of lipid metabolism (e.g. high levels of low-density lipoprotein cholesterol (LDL-C), elevated triglycerides and low levels of high-density lipoprotein cholesterol (HDL-C)) play a central role in the aetiology of cardiovascular disease (CVD). Nutraceutical combination together with a cholesterol- lowering action, when associated with suitable lifestyle, should furnish an alternative to pharmacotherapy in patients reporting statin-intolerance and in subjects at low cardiovascular risk. The present review is focused on nutraceuticals and their synergetic combinations demonstrating a beneficial effect in the management of dyslipidaemia. Several nutraceu…
MODULATION OF GRO-ALPHA AND TNF-ALPHA PRODUCTION BY PERIPHERAL BLOOD MONONUCLEAR CELLS TREATED WITH KILLED HELICOBACTER PYLORI.
2007
GRO-alpha seems to play an important role in recruiting and activating neutrophils during Helicobacter pylori infection. In the present study, we examined how treatment with killed H. pylori or/and live H. pylori may differentially influence the in vitro GRO-alpha and TNF-alpha release by peripheral blood mononuclear cells (PBMC). The amounts of TNF-alpha and GRO-alpha produced by PBMC after stimulation with live H. pylori were higher than those produced after stimulation with a combination of killed and live H. pylori and the latter were higher than those produced after stimulation with killed H. pylori. In conclusion, the treatment of peripheral blood mononuclear cells with killed H. pyl…
Identification of Novel Phosphopeptides After Simulated Digestion of αs2-casein by Tandem Mass Spectrometry
2006
Casein phosphopeptides (CPPs) are encrypted in αs1-, αs2-and β-casein (CN) and can be released by in vitro, in vivohydrolysis or food processing of dairy foods. Bovine αs2-CN contains two cluster sequences of anionic phosphoseryl and glutamyl residues SpSpSpEE in its structure (residues 8–12 and 56–63), which can modulate mineral bioavailability. In this study αs2-casein (αs2-CN) was subjected to simulated gastrointestinal digestion. CPPs released were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). Six novel αs2-CN derived CPPs, Three of them (αs2-CN(54–87)4P,αs2-CN(24–70)4P and αs2-…
Effects of the LPA1 Receptor Deficiency and Stress on the Hippocampal LPA Species in Mice
2019
Lysophosphatidic acid (LPA) is an important bioactive lipid species that functions in intracellular signaling through six characterized G protein-coupled receptors (LPA1-6). Among these receptors, LPA1 is a strong candidate to mediate the central effects of LPA on emotion and may be involved in promoting normal emotional behaviors. Alterations in this receptor may induce vulnerability to stress and predispose an individual to a psychopathological disease. In fact, mice lacking the LPA1 receptor exhibit emotional dysregulation and cognitive alterations in hippocampus-dependent tasks. Moreover, the loss of this receptor results in a phenotype of low resilience with dysfunctional coping in res…
The why, the how and the when of PGS 2.0
2016
STUDY QUESTION: We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0? STUDY FINDING: Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS. WHAT IS KNOWN ALREADY: It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst st…