Recombinant Salmonella choleraesuis Large-conductance mechanosensitive channel (mscL)
Description
**Introduction to Recombinant Salmonella choleraesuis Large-Conductance Mechanosensitive Channel (MscL)
The recombinant Salmonella choleraesuis large-conductance mechanosensitive channel (MscL) is a bacterial membrane protein engineered for study in heterologous systems. MscL functions as an emergency osmolyte-release valve, opening under extreme membrane tension to prevent cellular lysis during osmotic shock . In S. choleraesuis, a pathogen linked to systemic infections in humans and swine, MscL’s role extends to antibiotic resistance and biofilm formation . The recombinant version is produced in E. coli as a His-tagged protein (1–137 aa) for structural and functional analysis .
Gating Mechanism
MscL gates through a “lipid-moves-first” model, where lateral bilayer tension displaces lipids from hydrophobic pockets between TM helices, triggering conformational changes . Mutations like L89W (or M94 in E. coli) at the TM pocket entrance stabilize subconducting states, reducing activation thresholds .
| Mutation | Effect on Gating | Source |
|---|---|---|
| L89W | Destabilizes closed state; lowers activation pressure | |
| M94 | Analogous to L89W; enhances pore hydration in MD simulations |
Antibiotic Interactions
MscL facilitates uptake of aminoglycosides (e.g., dihydrostreptomycin) and release of potassium/glutamate, contributing to antibiotic resistance . In Actinobacillus pleuropneumoniae, mscL deletion reduces antibiotic tolerance .
| Antibiotic | Role in MscL Activity | Source |
|---|---|---|
| Dihydrostreptomycin | Binds near TM pockets; induces partial channel opening | |
| Aminoglycosides | Utilized MscL for cytoplasmic entry in E. coli |
Recombinant Production
The S. choleraesuis MscL is expressed as a His-tagged fusion protein in E. coli, purified via affinity chromatography, and reconstituted into liposomes for electrophysiology .
| Parameter | Value | Source |
|---|---|---|
| Purity | >90% (SDS-PAGE) | |
| Storage Buffer | Tris/PBS, 6% Trehalose, pH 8.0 | |
| Reconstitution | Deionized water (0.1–1.0 mg/mL) with glycerol |
Potential Applications
Product Specs
Note: While we prioritize shipping the format currently in stock, please specify your format preference in order notes for customized preparation.
Note: Standard shipping includes blue ice packs. Dry ice shipping requires prior arrangement and incurs additional charges.
The tag type is determined during the production process. If you require a specific tag, please inform us, and we will prioritize its development.
Target Background
A mechanosensitive channel that opens in response to membrane lipid bilayer stretch forces. It may play a role in regulating cellular osmotic pressure changes.
KEGG: sec:SCH_3346
