Part:BBa_K2933014
BCII family subclass B1 metallo-beta-lactamase, codon optimized in E. coli
This part encodes a protein called BcII, which is a metallo-beta-lactamase of subclass B1.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Usage and Biology
BcII is a type of subclass B metallo-beta-lactamase found in Bacillus anthracis. It can hydrolyzes Beta-lactam antibiotics to make pathogenic bacteria produce drug resistance. The bacterium Bacillus anthracis is responsible for causing anthrax infection, which is often fatal. Because symptoms arising from the bacterial infection are similar to a common cold,misdiagnosis in the early stage is possible and frequent. So the clinical strains carrying it become a great threat to human life and health. Beta-Lactamase inhibitors such as clavulanic acid, sulbactam, and tazobactam are commercially available and can be used with existing antibiotics to cure some antibiotic resistant infections, but these are not effective against MBLs. Although some potential inhibitors have the ability to inhibit it, there are no commercially available inhibitors of it. We use the protein to carry out high-throughput screening to find inhibitors that can inhibit it.
References
Sung-Kun Kim, Mara Demuth, Sara R. Schlesinger, Sung Joon Kim, Jonathan Urbanczyk, Robert W. Shaw & Hyunshun Shin (2016) Inhibition of Bacillusanthracis metallo-β- lactamase by compounds with hydroxamic acid functionality, Journal of Enzyme Inhibition and Medicinal Chemistry, 31:sup4, 132-137, DOI: 10.1080/14756366.2016.1222580
Molecular cloning
First,we obtained BcII by PCR.
Figure 1. The PCR result of BcII.
Then we used the vector pGEX-6p-1 to construct our expression plasmid. And then we converted the plasmid constructed to E. coli DH5α to expand the plasmid largely.After verification, it was determined that the construction is successful. We converted the plasmid to E. coli BL21(DE3) for expression and purification.
Figure 2. Left:The plasmid of BcII.Right:The verification results by enzyme digestion.
Expression and purification
Exploration of expression condition:
Take monoclone in the culture plate into LB tube and cultivate in shaking incubator overnight(10-12h) to activate bacteria.
Test the OD600 number of bacteria, then pipe 5-10ul into each new 5 mL LB tube. Don’t forget to add antibiotic into tubes and mark them.Cultivate in shaking incubator for 3-4 hours until the OD600 of bacteria range from 0.6 to 0.8.Set the gradient of condition to explore how to express it best.We use 0.2mM IPTG, 16°C/0.2mM IPTG, 37°C/0.4mM IPTG, 16°C/0.4mM IPTG, 37°C/0.6mM IPTG, 16°C/0.6mM IPTG, 37°C/0.8mM IPTG, 16°C/0.8mM IPTG, 37°Cas different conditions.
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