• Nanion技术: 离子通道研究的智能工具

    Nanion技术: 离子通道研究的智能工具

  • CardioExcyte 96 SOL:用光遗传的手段起搏心肌细胞

    CardioExcyte 96 SOL:用光遗传的手段起搏心肌细胞

  • SURFE²R 96SE: 非标记高通量转运体筛选

    SURFE²R 96SE: 非标记高通量转运体筛选

  • 脂双层记录: Orbit产品系列

    脂双层记录: Orbit产品系列

我们的产品目录

SyncroPatch 384i

SyncroPatch 384i

Patchliner

Patchliner

Port-a-Patch

Port-a-Patch

Port-a-Patch mini

Port-a-Patch mini

CardioExcyte 96

CardioExcyte 96

FLEXcyte 96

FLEXcyte 96

SURFE²R 96SE

SURFE²R 96SE

SURFE²R N1

SURFE²R N1

Orbit 16

Orbit 16

Orbit Mini

Orbit Mini

Vesicle Prep Pro

Vesicle Prep Pro

2015 - Quantification of Fluoroquinolone Uptake through the Outer Membrane Channel OmpF of Escherichia coli

icon pap  Port-a-Patch and   icon vpp   Vesicle Prep Pro publication in Journal of the American Chemical Society (2015)

Authors: 
Cama J., Bajaj H., Pagliara S., Maier T., Braun Y., Winterhalter M., Keyser U.F.

 

Journal: 
J. Am. Chem. Soc. (2015) 137(43):13836-13843


Abstract: 

Decreased drug accumulation is a common cause of antibiotic resistance in microorganisms. However, there are few reliable general techniques capable of quantifying drug uptake through bacterial membranes. We present a semiquantitative optofluidic assay for studying the uptake of autofluorescent drug molecules in single liposomes. We studied the effect of the Escherichia coli outer membrane channel OmpF on the accumulation of the fluoroquinolone antibiotic, norfloxacin, in proteoliposomes. Measurements were performed at pH 5 and pH 7, corresponding to two different charge states of norfloxacin that bacteria are likely to encounter in the human gastrointestinal tract. At both pH values, the porins significantly enhance drug permeation across the proteoliposome membranes. At pH 5, where norfloxacin permeability across pure phospholipid membranes is low, the porins increase drug permeability by 50-fold on average. We estimate a flux of about 10 norfloxacin molecules per second per OmpF trimer in the presence of a 1 mM concentration gradient of norfloxacin. We also performed single channel electrophysiology measurements and found that the application of transmembrane voltages causes an electric field driven uptake in addition to concentration driven diffusion. We use our results to propose a physical mechanism for the pH mediated change in bacterial susceptibility to fluoroquinolone antibiotics.


Download here

返回总览

Nanion运营博客

Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.