Part:BBa_K875009

LL 37 - Cathelicidin

The LL 37 cathelicidin is a human antimicrobial peptide.

The exact mechanism by which AMPs kill microorganisms is still under debate.

The eukaryotic toxin LL 37 was obtained by synthesis with the canonical prefix and suffix RFC10 compatible and it was optimized for E. coli expression.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Tec-Chihuahua 2019: Effect of LL 37 in E. coli growth

Team Tec-Chihuahua worked on the characterization of BBa_K875009. LL 37 has antimicrobial activity against both Gram-positive and Gram-negative bacteria. Escherichia coli is susceptible to the effects of this peptide, and since it's one of the most common chassis for recombinant protein production, the effects that LL 37 may have on the growth of E. coli when used for its expression were evaluated.
Expression of toxic proteins may adversely affect the viability of the chassis. In order to test E. coli as a viable host for LL 37 production, E. coli BL21 (DE3) cells were transformed with part BBa_K2959000 which is a composite capable of expressing LL 37 under the regulation of the T7 promoter. Three flasks with 30 mL of LB broth were inoculated with 3 mL of an overnight culture of transformed cells. Another flask with 30 mL of LB broth was inoculated with 3 mL of untransformed cells to use as a control. The four flasks were incubated at 37°C and 225 rpm until OD₆₀₀ reached 0.8. The flasks with transformed cells were treated with different concentrations of IPTG (0.1, 0.5, and 1 mM) to induce protein production. Then, optical density was measured every hour for five hours to measure growth. Results were recorded in the following table and chart.