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Channel Formation by LktA of Mannheimia (Pasteurella) haemolytica in Lipid Bilayer Membranes and Comparison of Channel Properties with Other RTX-Cytolysins
- Source :
- Toxins, Volume 11, Issue 10, Toxins, Vol 11, Iss 10, p 604 (2019)
- Publication Year :
- 2019
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2019.
-
Abstract
- Cytolysin LktA is one of the major pathogenicity factors of Mannheimia haemolytica (formerly Pasteurella haemolytica) that is the cause of pasteurellosis, also known as shipping fever pneumonia, causing substantial loss of sheep and cattle during transport. LktA belongs to the family of RTX-toxins (Repeats in ToXins) that are produced as pathogenicity factors by a variety of Gram-negative bacteria. Sublytic concentrations of LktA cause inflammatory responses of ovine leukocytes. Higher concentrations result in formation of transmembrane channels in target cells that may cause cell lysis and apoptosis. In this study we investigated channel formation by LktA in artificial lipid bilayer membranes made of different lipids. LktA purified from culture supernatants by polyethylene glycol 4000 precipitation and lyophilization had to be activated to frequently form channels by solution in 6 M urea. The LktA channels had a single-channel conductance of about 60 pS in 0.1 M KCl, which is about one tenth of the conductance of most RTX-toxins with the exception of adenylate cyclase toxin of Bordetella pertussis. The LktA channels are highly cation-selective caused by negative net charges. The theoretical treatment of the conductance of LktA as a function of the bulk aqueous concentration allowed a rough estimate of the channel diameter, which is around 1.5 nm. The size of the LktA channel is discussed with respect to channels formed by other RTX-toxins. We present here the first investigation of LktA in a reconstituted system.
- Subjects :
- Bordetella pertussis
Lysis
Health, Toxicology and Mutagenesis
mannheimia haemolytica
lcsh:Medicine
Toxicology
01 natural sciences
Microbiology
03 medical and health sciences
shipping fever pneumonia
0103 physical sciences
medicine
Lipid bilayer
030304 developmental biology
0303 health sciences
Transmembrane channels
Mannheimia hemolytica
010304 chemical physics
biology
Chemistry
RTX-toxin
lcsh:R
RTX toxin
biology.organism_classification
medicine.disease
cytolysin
lipid bilayer membrane
channel formation
Adenylate Cyclase Toxin
Cytolysin
Pasteurellosis
Subjects
Details
- Language :
- English
- ISSN :
- 20726651
- Database :
- OpenAIRE
- Journal :
- Toxins
- Accession number :
- edsair.doi.dedup.....682b2c17f1c95d57ac95ac9d050b1abc
- Full Text :
- https://doi.org/10.3390/toxins11100604