Part:BBa_K1727000

Signiferin with signal peptide

Signiferin is a kind of antimicrobial peptide (AMPs) and it is a stable peptide that has extensive abilities to kill or inhibit the growth of bacteria. Signiferin has demonstrated effectiveness in killing Methicillin-Resistant Staphylococcus aureus (MRSA), and has been proven by the TU-Delft 2013 iGEM team. To increase efficiency in isolating our AMPs, we introduced a signal peptide upstream of the N-terminal of antimicrobial peptides to facilitate peptide production.

Fig.1 Gel electrophoresis for biobrick BBa_K1727000 Finally, we used EcoRI and PstI these two kinds of enzyme to check the insert really contain in the biobrick. We used 2% gel. The size of signiferin insert should be 100 to 200 bp. There is band on the sample 2 of enzyme digest product. As the result, we can make sure that the signiferin has been ligated in backbone.

Peptide structure prediction

We had modified the amino acid sequence by attached an Ala at the N-terminal of Signiferin to facilitate the secreting process. And we had used structure prediction software to analysis if the attached Ala affect the peptide folding process or not.

Fig.2 The result of structure prediction

Through the secondary structure predicted. The result shows the attached of Ala didn’t affect peptide-folding process. It is still α-helix structure.

Disinfection ability of Signiferin

Fig.3 Chart of Signiferin disinfection ability to S. aureus

We had tested the disinfection efficiency of Signiferin on S. aureus to prove our system is work. As the chart we can see that Signiferin has ability to kill S. aureus. But the effect is not obvious. We speculated that the concentration is not enough to see the best efficiency. We will concentrate the peptides solution to do further experiments.

Sequence and Features

Assembly Compatibility:

• 10
  INCOMPATIBLE WITH RFC[10]

  Illegal EcoRI site found at 7
  Illegal XbaI site found at 174
  Illegal PstI site found at 168
  
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal EcoRI site found at 7
  Illegal PstI site found at 168
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal EcoRI site found at 7
  Illegal BamHI site found at 162
  Illegal XhoI site found at 1
  
• 23
  INCOMPATIBLE WITH RFC[23]

  Illegal EcoRI site found at 7
  Illegal XbaI site found at 174
  Illegal PstI site found at 168
  
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal EcoRI site found at 7
  Illegal XbaI site found at 174
  Illegal PstI site found at 168
  
• 1000
  COMPATIBLE WITH RFC[1000]