Recombinant Escherichia coli Beta-lactamase TEM (bla)

The DNA coding sequence translated into the Escherichia coli bla protein sequence (24-286aa) was fused with the N-terminal 6xHis-SUMO tag sequence to form the recombinant DNA, which was inserted into an expression vector. The reconstructed expression vector was transformed into the E.coli for follow-up expression. The product underwent purification to obtain the recombinant Escherichia coli bla protein with N-terminal 6xHis-SUMO tag. The SDS-PAGE analysis determined its purity higher than 90%. After electrophoresis, a 45 kDa protein band was observed on the gel.

bla is a gene encoding a protein called Beta-lactamase TEM (also known as Penicillinase) in E.coli and belongs to class-A beta-lactamase family. This protein is the most commonly encountered beta-lactamase in Gram-negative bacteria. The production of penicillinase is the main cause of ampicillin resistance in E. coli. Furthermore, this protein is also responsible for the ampicillin and penicillin resistance that is seen in H. influenzae and N. gonorrhoeae in increasing numbers. Although TEM-type beta-lactamases are most often found in E. coli and K. pneumoniae, they are also found in other species of Gram-negative bacteria with increasing frequency.