Search results for "Secretion"

Pushing the limits of STEC molecular risk assessment: identification of genes specifically induced in vivo as potential new genetic biomarkers

2017

National audience; Epidemiologic studies reveal that only few virulence factors are frequently associated with Shiga toxin-producing Escherichia coli (STEC) strains that cause severe disease in humans. Among them, Shiga toxins (Stx) is required for the development of the most severe symptoms in STEC infected patients but is not strictly sufficient to make an E. coli strain pathogenic to human. Indeed, many STEC strains isolated from rearing animals have never been implicated in human disease. It therefore appears crucial to increase our knowledge on STEC pathogenesis at the molecular level. We developed a RIVET (Recombination-based in vivo expression technology) strategy in order to identif…

Distinctive amino acid residue periodicities in terminal sequences of type III and type I secreted proteins from proteobacteria

2007

AbstractThe Fourier transform (FT) method was applied to specify the distribution of 14 predefined groups of amino acids (64 residues) at both termini of annotated type III and type I secreted proteins from proteobacteria. Type I proteins displayed a higher occurrence of significant periodicities at both C-and N-termini, indicating potent features to discriminate between secretion types, particularly by the use of variables selected from the full periodicity profiles at 19 orders of FT. The Fishers linear discriminant analysis, together with the stepwise selection of variables throughout equal pairs of combinations for all predefined groups of residues, revealed the C-terminal harmonics of …

Potential anticarcinogenic peptides from bovine milk.

2012

Bovine milk possesses a protein system constituted by two major families of proteins: caseins (insoluble) and whey proteins (soluble). Caseins (αS1,αS2,β, andκ) are the predominant phosphoproteins in the milk of ruminants, accounting for about 80% of total protein, while the whey proteins, representing approximately 20% of milk protein fraction, includeβ-lactoglobulin,α-lactalbumin, immunoglobulins, bovine serum albumin, bovine lactoferrin, and lactoperoxidase, together with other minor components. Different bioactivities have been associated with these proteins. In many cases, caseins and whey proteins act as precursors of bioactive peptides that are released, in the body, by enzymatic pro…

Chaperonopathies and chaperonotherapy. Hsp60 as therapeutic target in cancer: potential benefits and risks.

2013

In this minireview we focus on Hsp60 as a target for anticancer therapy. We discuss the new concepts of chaperonopathies and chaperonotherapy and present information on Hsp60 localization in the cell membrane of human tumor cells. We describe novel mechanisms for Hsp60 reaching the extracellular environment that involve membrane-associated stages, as well as data on anti-Hsp60 antibodies found in human sera, both in normal subjects and patients affected by autoimmune diseases. Finally, we discuss possible therapeutic applications of anti-Hsp60 antibodies in cancer treatment, evaluating also side effects on non-tumor cells. In conclusion, the way for investigating Hsp60-targeted anti-tumor t…

Bioaccessibility Study of Aflatoxin B1 and Ochratoxin A in Bread Enriched with Fermented Milk Whey and/or Pumpkin

2021

The presence of mycotoxins in cereals and cereal products remains a significant issue. The use of natural ingredients such as pumpkin and whey, which contain bioactive compounds, could be a strategy to reduce the use of conventional chemical preservatives. The aim of the present work was to study the bioaccessibility of aflatoxin B1 (AFB1) and ochratoxin (OTA) in bread, as well as to evaluate the effect of milk whey (with and without lactic acid bacteria fermentation) and pumpkin on reducing mycotoxins bioaccessibility. Different bread typologies were prepared and subjected to an in vitro digestion model. Gastric and intestinal extracts were analyzed by HPLC–MS/qTOF and mycotoxins bio…

The pathophysiology of intestinal lipoprotein production

2015

Intestinal lipoprotein production is a multistep process, essential for the absorption of dietary fats and fat-soluble vitamins. Chylomicron assembly begins in the endoplasmic reticulum with the formation of primordial, phospholipids-rich particles that are then transported to the Golgi for secretion. Several classes of transporters play a role in the selective uptake and/or export of lipids through the villus enterocytes. Once secreted in the lymph stream, triglyceride-rich lipoproteins (TRLs) are metabolized by Lipoprotein lipase (LPL), which catalyzes the hydrolysis of triacylglycerols of very low density lipoproteins (VLDLs) and chylomicrons, thereby delivering free fatty acids to vario…

Genetic and environmental factors associated with the virulence of fish pathogen Flavobacterium columnare

2016

Deoxycholic Acid Methyl Ester — a Novel Bacterial Metabolite of Cholic Acid

1985

Summary Methyl deoxycholate was identified as a novel bacterial metabolite of cholate, produced anaerobically by strains of most saccharolytic Bacteroides species ( B. distasonis, B. eggerthii, B. fragilis, B. incommunis, B. thetaiotaomicron, B. uniformis, B. variabilis, B. vulgatus , and unnamed species). It was also detected with a few strains of Eubacterium and Lactobacillus species. Among 2476 freshly isolated human fecal cultures the frequency of carboxyl group esterification was comparable with that of 7α-dehydroxylation (92 versus 102 cultures). Both activities were, however, lost for unknown reasons after serial transfers. Two of ten mixed fecal cultures tested esterified 3α,7α- or …

The effect of amphiphilic compounds on the secretion of levansucrase by Zymomonas mobilis

2005

Abstract The effect of some aliphatic (n-butanol to n-hexadecanol) and aromatic (benzyl and phenethyl alcohols), anesthetics (procaine) and surfactants (Tween 20 to Tween 80) on the secretion of levansucrase by the levan-producing strain of Gram-negative ethanologenic bacteria Zymomonas mobilis 113S were examined in this study. During incubation of Z. mobilis cells with sucrose (10 mM) a decrease of the levansucrase activity was observed in the presence of these amphiphilic compounds concomitantly with an increase of a total amount of protein in the medium. Since none of the compounds under study had any effect on enzyme activity in vitro observed structure- and concentration-dependent rela…

Follicle Cells of Styela plicata Eggs (Ascidiacea)

2001

Styela plicata eggs are surrounded by large follicle cells that at LM appear as highly vacuolated and columnar in shape; at the apical end of each cell lies a very large and clear vacuole, half of which extends inward. Electron microscope observations show a Single layer of largely spaced box-like follicle cells; the close cell-cell contact at their base is realized by interdigitations. The cell surface shows a peculiar structure, more developed in the latero-basal regions, consisting of a complex of membrane extensions, i.e. microvilli, filopodia and lamellipodia. Filopodia irradiate in all directions towards the adjacent cells and the outermost vitelline coat, thus creating a complex netw…