Synthesis and characterization of thermoreversible biopolymer microgels based on hydrogen bonded nucleobase pairing.
We describe the synthesis and characterization of a thermoreversibly cross-linked biopolymer microgel based on protein, DNA, and peptide nucleic acid (PNA) components. The DNA assembles into a trifunctional three-way junction (TWJ) with single-stranded overhangs. PNA oligomers complementary to these overhangs and bearing terminal biotin groups hybridize to the DNA TWJ and simultaneously bind to the tetrafunctional protein avidin, leading to a cross-linked system. Dynamic light scattering experiments reveal that micron-sized particles are formed. Static light scattering was used to characterize the internal structure of these microgels, which were found to have a fractal dimension of 1.85, indicative of a loose network structure. Heating disrupts the weakest component in the system, namely the PNA-DNA hybrid, resulting in dissolution of the microgel, while cooling restores the hydrogen bonding leading to reassembly of the microgel. Variation of the nucleotide sequence permits tuning of the gelation temperature with fine control.
Cao
Rong
R
Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213-3890, USA.
Gu
Zhenyu
Z
Hsu
Lorraine
L
Patterson
Gary D
GD
Armitage
Bruce A
BA
D001360:Avidin / Q000737:chemistry; D001483:Base Sequence; D001710:Biotin / Q000737:chemistry; D004247:DNA / Q000138:chemical synthesis / Q000737:chemistry*; D005782:Gels; D006358:Hot Temperature; D006860:Hydrogen Bonding; D008027:Light; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D020135:Peptide Nucleic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D011506:Proteins / Q000138:chemical synthesis / Q000737:chemistry*; D012542:Scattering, Radiation
D005782:Gels; D009841:Oligonucleotides; D020135:Peptide Nucleic Acids; D011506:Proteins; D001360:Avidin; D001710:Biotin; D004247:DNA