9 research outputs found
Study Of The Drug/lipid Interactions Between Cephalosporin Antibiotics And Liposomes By Complementary Techniques
Study Of The Drug/lipid Interactions Between Cephalosporin Antibiotics And Liposomes By Complementary Techniques
Modelando con UML el proceso de evaluaci贸n de productos de software utilizando el enfoque GQM
El enfoque GQM (Meta-Pregunta-M茅trica, por sus siglas en ingl茅s) ha sido utilizado en el proceso de evaluaci贸n de calidad de productos de software, como instancia de un paradigma de medida. Sin embargo, este enfoque no tiene asociado diagramas o elementos visuales que permitan una mejor comunicaci贸n entre los encargados de la evaluaci贸n y los desarrolladores, por lo que se hace una propuesta para usar UML (Unified Modeling Language) como lenguaje de especificaci贸n para describir su estructura y a partir de esto, usar el perfil de pruebas de UML (UTP, UML Testing Profile) para la especificaci贸n del proceso, mediante la descripci贸n de la arquitectura, el comportamiento, los datos y la gesti贸n de las pruebas
Liposome Steady-state Anisotropy Of E.coli Total Lipid Extracts: A Tool To Better Understand Antibiotic Translocation In A Bacterial Environment
Molecular Basis of Enrofloxacin Affinity to a Membrane Channel of E.聽Coli - When Binding Does Not Imply Translocation
Molecular Basis of Enrofloxacin Translocation through OmpF, an Outer Membrane Channel of Escherichia coli - When Binding Does Not Imply Translocation
The molecular pathway of enrofloxacin, a fluoroquinolone antibiotic, through the outer membrane channel
OmpF of Escherichia coli is investigated. High-resolution ion current fluctuation analysis reveals a strong
affinity for enrofloxacin to OmpF, the highest value ever recorded for an antibiotic-channel interaction. A
single point mutation in the constriction zone of OmpF, replacing aspartic acid at the 113 position with
asparagine (D113N), lowers the affinity to a level comparable to other antibiotics. All-atom molecular dynamics
simulations allow rationalizing the translocation pathways: wild-type OmpF has two symmetric binding sites
for enrofloxacin located at each channel entry separated by a large energy barrier in the center, which inhibits
antibiotic translocation. In this particular case, our simulations suggest that the ion current blockages are
caused by molecules occupying either one of these peripheral binding sites. Removal of the negative charge
on position 113 removes the central barrier and shifts the two peripheral binding sites to a unique central site,
which facilitates translocation. Fluorescence steady-state measurements agree with the different location of
binding sites for wild-type OmpF and the mutant. Our results demonstrate how a single-point mutation of the
porin, and the resulting intrachannel shift of the affinity site, may substantially modify translocation