Towards understanding single-channel characteristics of OccK8 purified from Pseudomonas aeruginosa
European Biophysics Journal, cilt.50, sa.1, ss.87-98, 2021 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 50 Sayı: 1
- Basım Tarihi: 2021
- Doi Numarası: 10.1007/s00249-021-01498-5
- Dergi Adı: European Biophysics Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, EMBASE, INSPEC, MEDLINE
- Sayfa Sayıları: ss.87-98
- Anahtar Kelimeler: Antibiotic resistance, Pseudomonas aeruginosa, Outer membrane carboxylate channels porin K8 (OccK8), Lipid bilayer electrophysiology
- Ankara Yıldırım Beyazıt Üniversitesi Adresli: Evet
Özet
© 2021, European Biophysical Societies' Association.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.