Construction of peptide/plasmid DNA complexes for plant gene transfection via the basic leucine zipper domain

An important method for plant genetic modification is using peptide/pDNA complexes to transfer genes into plant cells. With conventional carrier peptides, the peptide sequence must contain a high amount of cationic amino acids to condense and introduce pDNA. As a result, the dissociation of pDNA from the complex is inefficient, often causing problems. Herein, we designed a new peptide carrier that mimics the basic leucine zipper (bZIP) domain of DNA-binding proteins, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding and cell-penetrating motif (U = α-aminoisobutyric acid). After (KUA)3-(LU)4 peptide was mixed with pDNA, DNA molecules were condensed to form nanoparticles of approximately 130 nm. Furthermore, when complexes of (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), expression of the reporter protein was detected in the plant cells. Thus, (KUA)3-(LU)4 peptide that mimics the bZIP domain is a novel and efficient carrier for pDNA with high dissociation efficiency. A new peptide carrier that mimics the basic leucine zipper domain (bZIP) of DNA-binding proteins was designed, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding motif (U = α-aminoisobutyric acid). When mixed with pDNA, (KUA)3-(LU)4 peptide condensed DNA molecules to form nanoparticles. Furthermore, when complexes of the (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), the reporter protein was expressed in plant cells. Thus, (KUA)3-(LU)4 is an efficient carrier of pDNA with high dissociation efficiency.