Team:NCTU Formosa/Wet Lab/Expression

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Cloning

To ensure our target genes were successfully cloned into the PSB1C3 backbone, we ran the electrophoresis of Taq PCR products to check the sizes of the insert genes.

All of the sequences contained T7 promoter, RBS, bacteriocin, intein and CBD, were shown in Figure 1.

Figure 1: Our BioBrick design
Figure 2: The electrophoresis results of Leucocyclicin Q, Enteroicin B, Bovicin HJ50 and Enterocin 96.
Figure 3: The electrophoresis results of Lacticin Z, Enteroicin A, Durancin and Subtilosin.

Protein Expression

Table 1: The Bacteriocins we selected.

Bacteriocin

Mass (kDa)

Enterocin B 7.5
Enterocin 96 7.9
Bovicin HJ50 6.25
Durancin 7.3
Leucocyclicin Q 6.4
Lacticin Z 5.9

We tried to get the bacteriocin from E. coli ER2566. To check whether the protein had been expressed, we used SDS-PAGE to confirm. Because our sequences content Intein and Chitin Binding Domain (CBD), which are 28 kDa, the result should be check as the bacteriocins’ initial mass plus 28 kDa. The figure showed our SDS-PAGE result. From here, we can know our target bacteriocin is produced.

Figure 4: SDS-PAGE result of Enterocin 96 and Enteroicin B.

(N1) Negative control: E. coli ER2566 without plasmid (N2) Negative control: E. coli ER2566 with empty plasmid
(A) Enterocin 96+intein+CBD (35.9kDa) (B) Enteroicin B+intein+CBD (35.5kDa)

Figure 5: SDS-PAGE result of Leucocyclicin Q and Durancin.

(N1) Negative control: E. coli ER2566 without plasmid (N2) Negative control: E. coli ER2566 with empty plasmid
(C) Leucocyclicin Q+intein+CBD (34.4kDa) (D) Durancin +intein+CBD (35.3kDa)