Referenced in: none

Automatically associated channels: Slo1

Title: Transport across the outer membrane porin of mycolic acid containing actinomycetales: Nocardia farcinica.

Authors: Pratik Raj Singh, Harsha Bajaj, Roland Benz, Mathias Winterhalter, Kozhinjampara R Mahendran

Journal, date & volume: Biochim. Biophys. Acta, 2015 Feb , 1848, 654-61

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25462168

Abstract
The role of the outer-membrane channel from a mycolic acid containing Gram-positive bacteria Nocardia farcinica, which forms a hydrophilic pathway across the cell wall, was characterized. Single channel electrophysiology measurements and liposome swelling assays revealed the permeation of hydrophilic solutes including sugars, amino acids and antibiotics. The cation selective N. farcinica channel exhibited strong interaction with the positively charged antibiotics; amikacin and kanamycin, and surprisingly also with the negatively charged ertapenem. Voltage dependent kinetics of amikacin and kanamycin interactions were studied to distinguish binding from translocation. Moreover, the importance of charged residues inside the channel was investigated using mutational studies that revealed rate limiting interactions during the permeation.