Cell-Penetrating Peptide-Mediated Transformation of Large Plasmid DNA into Escherichia coli

The highly efficient genetic transformation of cells is essential for synthetic biology procedures, especially for the transformation of large gene clusters. In this technical note, we present a novel cell-penetrating peptide (CPP)-mediated large-sized plasmid DNA transformation system for Escherichia coli. A large plasmid (pMSR227, 205 kb) was complexed with cationic peptides containing a CPP motif and was successfully transformed into E. coli cells. The transformants containing the plasmid DNA exhibited expression of a reporter gene encoding a red fluorescent protein. The transformation efficiency was significantly higher than that obtained using the heat-shock method and was similar to that of electroporation. This technique can be used as a platform for the simple and highly efficient transformation of large DNA molecules under mild conditions without causing significant damage to DNA, accelerating synthetic biology investigations for the design of genetically engineered microorganisms for industrial purposes.