Towards understanding single-channel characteristics of OccK8 purified from Pseudomonas aeruginosa.
Eur Biophys J
; 50(1): 87-98, 2021 Jan.
Article
in En
| MEDLINE
| ID: mdl-33481046
ABSTRACT
Antibiotic resistance in Gram-negative bacteria causes serious health issues worldwide. Bacteria employ several resistance mechanisms to cope with antimicrobials. One of their strategies is to reduce the permeability of antibiotics either through general diffusion porins or substrate-specific channels. In this study, one of the substrate-specific channels from Pseudomonas aeruginosa, OccK8 (also known as OprE), was investigated using single-channel electrophysiology. The study also includes the investigation of permeability properties of several amino acids with different charged groups (i.e. arginine, glycine and glutamic acid) through OccK8. We observed four different conformations of the same OccK8 channel when inserted in lipid bilayers. This is in contrast to previous studies where heterologous expressed OccK8 in E. coli showed only one conformation. We hypothesized that the difference in our study was due to the expression and purification of the native channel from P. aeruginosa. The single-channel uptake characteristics of the porin showed that negatively charged glutamic acid preferentially interacted with the channel while the positively charged arginine molecule showed infrequent interaction with OccK8. The neutral amino acid glycine did not show any interaction at the physiological conditions.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pseudomonas aeruginosa
/
Bacterial Proteins
/
Porins
Type of study:
Prognostic_studies
Language:
En
Journal:
Eur Biophys J
Journal subject:
BIOFISICA
Year:
2021
Document type:
Article
Affiliation country:
Turkey