Difference between revisions of "Part:BBa K2599008"

Revision as of 13:43, 19 September 2018

T7 Promoter+RBS+Subtilosin+intein+CBD

NCTU_Formosa 2018 designed a composite part encoding the Subtilosin sequence (BBa_K2599000), and then combined with a T7 promoter (BBa_I712074), a lac operator (K1624002), a ribosome binding site (BBa_B0034), intein and chintin binding domain (CBD). Further information of our peptide can be found on our design page.

Figure 1 biobrick picture

Introduction

Bacillus subtilis produces a bacteriocin called Subtilosin that possesses antibacterial activity against certain gram-positive bacteria. The bacteriocins are a group of anitmicrobial peptides that are often distinguished from traditioinal antibiotics by their narrow range of avtivity against closely related bacteria.

Mechanism of Subtilosin

The bacteriocins inhibit their target organisms through pore formation. Though the mechanism of each inhibition is vary from species to species, the general process is conserved. Details are on our project page.

According to the reference, Subtilosin acts by fully depleting the transmembrane pH gradient (ΔpH) and causing an immediate efflux of intracellular ATP, but has no effect on the transmembrane electric potential. In addition, the paper also shows that membrane permeabilization occurred at concentrations of subtilosin that were significantly higher than the MIC level of E. coli tested strains.

Features of Subtilosin

1. Species Specific

Bacteriocin target strains or closely related species. Subtilosin has specificity to Bacillus subtilis , Listeria monocytogenes , Enterococcus faecalis , etc.

2. Eco-friendly

Since subtilosin is a polypeptide naturally produced by bacteria itself and can inhibit other bacteria without much environment impact. It don't pose threat to other organisms like farm animals or humans. Therefore, this toxin will not cause safety problem.

3. Biodegradable

Subtilosin is a short peptide that will degrade in a short time. After degradation, this antibacterial peptide is harmless to our environment.

Experiment Result

Cloning

We conbined our toxic gene to pSB1C3 backbone and conducted PCR to check the size of our part. The Subtilosin sequence length is around 147 b.p. For the composite part, the sequence length should be near at 1191 b.p.

Figure 2 PCR

Expressing

We chose E. coli 2566 strain to express our antibacterial peptides. The expression of Subtilosin fused with intein was induced by IPTG in E. coli , and intein-subtilosin specifically bound to the column through chitin binding domain would be purified.

Figure 3 SDS

Sequence and Features

Reference