Difference between revisions of "Part:BBa K541515"

Latest revision as of 14:35, 22 September 2011

Limulus anti-LPS factor (LALF) for Bacillus subtilis

Constitutive promoter veg(BBa_K143012) coupled to the strong Ribosome Binding Site spoVG(BBa_K143021) from B. subtilis. These parts have been taken from 2008_Imperial_Collage. Pveg is a constitutive promoter that constitutively expresses the P43 protein in B. subtilis.

SpoVG is an endogenous ribosome binding site from B. subtilis. The sequence of the spoVG ribosome binding site is AAAGGUGGUGA which is complementary to the sequence UUUCCUCCACU from the 3' region of the 16s rRNA from B. subtilis.

SacB is a signal peptide used in the Sec-SRP (secretory signal recognition particle) pathway by B. subtilis. Signal peptides are responsible for directing preproteins (secretory proteins with a signal peptide region attached) through an appropriate secretory pathway. In the case of the Sec-SRP signal peptide, they direct preproteins from the cytoplasm into the growth medium.

Lipopolysaccharide (LPS), or endotoxin, is the major mediator of septic shock, a serious complication of Gram-negative bacterial infections in humans. Molecules that bind LPS and neutralize its biological effects or enhance its clearance could have important clinical applications. Limulus anti-LPS factor (LALF) binds LPS tightly, and, in animal models, reduces mortality when administered before or after LPS challenge or bacterial infection. The wedge- shaped molecule has a striking charge distribution and amphipathicity that suggest how it can insert into membranes. The binding site for LPS probably involves an extended amphipathic loop, and it has been proposed that two mammalian LPS-binding proteins will have a similar loop. The amphipathic loop structure may be used in the design of molecules with therapeutic properties against septic shock.

Experiment

We aimed to stop E.coli growth by binding LPS layer on its cell Wall with our LALF protein. We performed several experiments whether the protein works or not. We spread E.coli with RFP onto four plates that two of them as control group and the other as experimental group. Additionally, we added 10 ul B.subtilis liquid cultures onto one expermental plate and 10 ul supernatant onto the other one. Respectively, we saw that on the both of the zones where supernatant or liquid culture with LALF had been added, there was no E.coli colony. We deduced that our protein works and stops E.coli growth both in liquid culture or supernatant.

To check out our other experiments and see more results, visit Experience site of the device

Sequence and Features