Part:BBa_K5335008

SpyCatcher-Linker-Cry6Aa2-Linker-CPPs+SpyTag-6*His

SpyCatcher and SpyTag are able to connect via isopeptides, so Cry6Aa2 will load onto VLP (virus-like particles) through these two connector proteins and act upon the release of VLP. Cell Penetrating Peptides (CPPs) fuse to the C-terminal of Cry6Aa and help the Cry6Aa2 protein enter the cells of nematode worms to trigger the necrosis pathway

Sequence and Features

Assembly Compatibility:

• 10
  INCOMPATIBLE WITH RFC[10]

  Illegal PstI site found at 1517
  
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 7
  Illegal NheI site found at 30
  Illegal PstI site found at 1517
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal XhoI site found at 1622
  
• 23
  INCOMPATIBLE WITH RFC[23]

  Illegal PstI site found at 1517
  
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal PstI site found at 1517
  Illegal AgeI site found at 692
  
• 1000
  COMPATIBLE WITH RFC[1000]

Usage and Biology

The SpyCatcher-SpyTag system was modified from the CnaB2 domain of Streptococcus pyogenes fibronectin binding protein. SpyCatcher is an immunoglobulin-like protein with a molecular weight of about 12 kDa, and SpyTag is a short peptide composed of 13 residues that can recognize each other with high affinity and spontaneously form isopeptide bonds.Cell Penetrating Peptides (CPPs), also known as Trojan peptides, are a family of short hydrophobic peptides that can pass through the cell membrane. A variety of cellular transmembrane peptides have been found to facilitate the uptake of various molecules by cells, such as RNA/DNA, peptides, radioisotopes, liposomes, nanoparticles, and protein molecules.In our project, we fused Cry6Aa2 with SpyCatcher and CPPs, attaching it to virus-like particles with SpyTag, releasing it into the soil environment through the cleavage of engineered bacteria, and CPPs helped our insecticidal proteins enter the nematode body for killing.

Figure 1. SpyCatcher-Cry6Aa2-CPPs+SpyTag-6*His(pET28a)plasmid vector

Characterization

Colony PCR

We designed an forward primer inside the spycatcher-linker-cry6aa2-linker-cpps gene sequence and a reverse primer on spytag-6*his to serve as a primer for our colony PCR, as this may reduce the production of false positives.We chose 2× Magic Green Taq SuperMix.It contains DNA Polymerase, dNTP, and an loading buffer system.The PCR reaction consisted of 15 μL 2 × Magic Green Taq SuperMix, 1.5 μL forward primer (3.75 mM), 1.5 μL reverse primer (3.75 mM), 11 μL ddH₂O and 1 μL colony.

SDS-PAGE

Figure 2. SDS-PAGE for Bacterial toal protein
M:Protein marker;Ctrl:Empty Escherichia coli BL21(DE3).Ex:Escherichia coli BL21(DE3) that has been introduced into the expression vector.