Anti-infectious properties of the probiotic Saccharomyces cerevisiae CNCM I-3856 on enterotoxigenic E. coli (ETEC) strain H10407

2018 ◽  
Vol 102 (14) ◽  
pp. 6175-6189 ◽  
Author(s):  
C. Roussel ◽  
A. Sivignon ◽  
A. de Vallée ◽  
G. Garrait ◽  
S. Denis ◽  
...  
2013 ◽  
Vol 288 (20) ◽  
pp. 13951-13959 ◽  
Author(s):  
Yan Zhang ◽  
Xiuxiang An ◽  
JoAnne Stubbe ◽  
Mingxia Huang

The small subunit (β2) of class Ia ribonucleotide reductase (RNR) houses a diferric tyrosyl cofactor (Fe2III-Y•) that initiates nucleotide reduction in the large subunit (α2) via a long range radical transfer (RT) pathway in the holo-(α2)m(β2)n complex. The C-terminal tails of β2 are predominantly responsible for interaction with α2, with a conserved tyrosine residue in the tail (Tyr356 in Escherichia coli NrdB) proposed to participate in cofactor assembly/maintenance and in RT. In the absence of structure of any holo-RNR, the role of the β tail in cluster assembly/maintenance and its predisposition within the holo-complex have remained unknown. In this study, we have taken advantage of the unusual heterodimeric nature of the Saccharomyces cerevisiae RNR small subunit (ββ′), of which only β contains a cofactor, to address both of these issues. We demonstrate that neither β-Tyr376 nor β′-Tyr323 (Tyr356 equivalent in NrdB) is required for cofactor assembly in vivo, in contrast to the previously proposed mechanism for E. coli cofactor maintenance and assembly in vitro. Furthermore, studies with reconstituted-ββ′ and an in vivo viability assay show that β-Tyr376 is essential for RT, whereas Tyr323 in β′ is not. Although the C-terminal tail of β′ is dispensable for cofactor formation and RT, it is essential for interactions with β and α to form the active holo-RNR. Together the results provide the first evidence of a directed orientation of the β and β′ C-terminal tails relative to α within the holoenzyme consistent with a docking model of the two subunits and argue against RT across the β β′ interface.


Author(s):  
Alequis Tomás Pavón Oro

El cáncer es la segunda causa de muerte en el mundo, y específicamente en Chile el cáncer colorrectal es el único que presenta un aumento sostenido de la mortalidad en la última década. La búsqueda de nuevos agentes quimioterapeúticos anticancerígenos ha propuesto a los microorganismos extremófilos como una fuente potencial para obtener moléculas citotóxicas, que induzcan apoptosis en las células tumorales. Las condiciones extremas del continente antártico y las presiones selectivas por el espacio y los nutrientes que se producen entre los microorganismos del rizobioma de la planta Deschampsia antarctica Desv sugirieron como hipótesis que las bacterias rizosféricas aisladas en la Antártica secretan al sobrenadante de cultivo moléculas bioactivas que inhiben la invasión y proliferación de líneas tumorales humanas de origen colorrectal mediante un mecanismo apoptótico. En este sentido, el objetivo general del trabajo fue identificar y caracterizar a moléculas bioactivas con acción antinvasiva y antiproliferativa, además, determinar el mecanismo inhibitorio de la proliferación en líneas tumorales humanas de origen colorrectal. Los resultados del primer objetivo específico demostraron que los sobrenadantes de cultivo de los aislados rizosféricos antárticos K2 y MI disminuyeron la viabilidad de la línea celular de adenocarcinoma colorrectal LoVo en el ensayo de reducción metabólica del MTT. Además, como los sobrenadantes no tuvieron efecto en la viabilidad de las bacterias E. coli y Staphylococcus aureus, y tampoco en los hongos unicelulares Candida albicans y Saccharomyces cerevisiae, el resultado indicó que la actividad antiproliferativa fue selectiva hacia la línea celular LoVo.


OALib ◽  
2015 ◽  
Vol 02 (03) ◽  
pp. 1-5
Author(s):  
Nora Guida ◽  
Marcela Mascolo ◽  
Mariano Laino ◽  
Carla Bustos ◽  
Pablo Franco

2020 ◽  
Vol 11 (3) ◽  
pp. 4353-4358
Author(s):  
Saripah Salbiah Syed Abdul Azziz ◽  
Ahmed Kareem Obaid Aldulaimi ◽  
Saadon Abdulla Aowda ◽  
Yuhanis Mhd Bakri ◽  
Ali Arkan Majhool ◽  
...  

The study aimed to isolate and identify the phytochemical components of Polyalthia lateriflora leaves and evaluate the antimicrobial activity. Six well-known compounds, including three triterpene lupeol (1) betulinic acid (2), β-Sitosterol-β-D-glucoside (3) and three oxoaporphine alkaloids O-methylmoschotaline (4), liriodenine (5) and atherosperminine (6). Structural elucidation of compounds were established through spectroscopic techniques such as 1D and 2D NMR (1H and 13C, DEPT, COSY, NOESY, HMBC, HMQC), IR and LC-MS. The isolated compounds and crude extracted were tested for their antibacterial potential against several microorganisms including P. aeruginosa, E. coli, s, S. aureus, B. subtilis and Saccharomyces cerevisiae and its showed significant inhibition toward the organisms species with different concentration range.


2013 ◽  
Vol 5 (3) ◽  
pp. 499-513
Author(s):  
M. Z. Alam ◽  
L. Ragionieri ◽  
M. A. S. Santos ◽  
A. Iqbal

Enzymes and other protein purification using recombinant DNA technology have become popular due to scarcity of natural protein. Saccharomyces cerevisiae is a demanding host, since it facilitates protein expression by its relative simplicity, safe organisms, inexpensive and has many properties of eukaryotic expression system. As an alternative host we express E. coli lacZ gene with GST tag in Saccharomyces cerevisiae and successfully purified from soluble extracts. The concentration of soluble GST-? galactosidase protein was approximately 0.57 mg/ml of elution buffer yielded from 50 ml yeast cell culture. The ?-galactosidase protein from insoluble extract was low due to the increasing solubility of GST tag. Keywords: ?-galactosidase; Heterologous expression; GST tag; Affinity chromatography. © 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v5i3.13820 J. Sci. Res. 5 (3), 499-513 (2013)  


1992 ◽  
Vol 47 (3-4) ◽  
pp. 57
Author(s):  
M. Réglier ◽  
J. Kessl ◽  
M. Pierrot ◽  
J.C. Chaix ◽  
X-J Guo ◽  
...  

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
Mohd Kamuri ◽  
Zurina Zainal Abidin ◽  
Mohd Yaacob ◽  
Mohd Hamidon ◽  
Nurul Md Yunus ◽  
...  

This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2–24 s and a flow rate range of 1.2–9.6 μ L min − 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min − 1 at a constant frequency, voltage, and a low conductivity.


2010 ◽  
Vol 138 (5) ◽  
pp. S-51
Author(s):  
Adeline Sivignon ◽  
Pascal Vandekerckove ◽  
Nicolas Barnich ◽  
Georges Pignède ◽  
Arlette Darfeuille-Michaud

1997 ◽  
Vol 327 (3) ◽  
pp. 847-851 ◽  
Author(s):  
Zengji LI ◽  
Yue SUN ◽  
L. David THURLOW

Twenty-one RNA minihelices, resembling the coaxially stacked acceptor- /T-stems and T-loop found along the top of a tRNA's three-dimensional structure, were synthesized and used as substrates for ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli and Saccharomyces cerevisiae. The sequence of nucleotides in the loop varied at positions corresponding to residues 56, 57 and 58 in the T-loop of a tRNA. All minihelices were substrates for both enzymes, and the identity of bases in the loop affected the interaction. In general, RNAs with purines in the loop were better substrates than those with pyrimidines, although no single base identity absolutely determined the effectiveness of the RNA as substrate. RNAs lacking bases near the 5ʹ-end were good substrates for the E. coli enzyme, but were poor substrates for that from yeast. The apparent Km values for selected minihelices were 2-3 times that for natural tRNA, and values for apparent Vmax were lowered 5-10-fold.


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