Abstract
We developed two convenient methods for synthesis homogeneous DNA-protein conjugates. The methods are based on native chemical ligation that allows chemoselective joining of two unprotected molecules via a stable amide bond. Reagent 1 and 2 were synthesized for oligonucleotides modification with a cysteine and thioester, respectively. The amino functionalized oligonucleotides in various length and sequence were successfully converted to oligonucleotides carrying a cysteine or thioester group with new reagents. Recombinant green fluorescent protein carrying thioester group at C-terminus were expressed using intein-tag as model protein. Judging from the SDS-PAGE and MALDI-TOF-MS analysis, the oligonucleotide functionalized with 1 were successfully site-speficically ligated with C-terminus of the protein. The oligonucleotide modified with 2 can joined to recombinant protein that carrying cysteine at N-terminus. Our approach to construct homogeneous protein-DNA conjugate would provide a powerful method in the field of nano-bio technology.
