Yang courage TF Tianjin University \”should be of German\”: chiral carbon quantum dot analog regulation of topoisomerase I supercoiled DNA topology

Recently, the Institute of Chemical Engineering and Technology, Professor Yang Dayong research group published research on quantum dots simulate chiral carbon regulation topoisomerase I supercoiled DNA topology in the field of chemistry authoritative journal Angewandte Chemie (Applied Chemistry, Germany), found that the chiral mechanism carbon quantum dot analog topoisomerase clarify the system confirms the life of the molecule mechanism of gene transcription. School of Chemical Engineering and Technology Professor Li Fengfu Shuai and doctoral students as co-first authors. Partners include the Institute of Biophysics by researcher Gregory, Tianjin Medical University, Professor Liu Yang Ping, an associate professor Song Yuguang Li Boshi little peace talks. Study was funded by the National Natural Science Foundation and the Ministry of Science and major research projects.

DNA is a dual spiral structure of biological macromolecules, and the core of genetic material of living systems, guidance and development of the biological function of the operating life. Higher-order structure of DNA is also called DNA topology, means on the basis of the DNA double helix, further distort the specific spatial structure formation. Supercoiled DNA topology is the predominant form of supercoiled and controlled by adjusting the density of DNA topoisomerase. Topoisomerase and DNA binding can be catalyzed by DNA strand breaks, so as to control the topology of DNA, for DNA transcription and replication activities of life plays an important regulatory role. Wherein, topoisomerase I and may be connected to the catalytic instantaneous breaking the DNA double helix structure of single strand DNA, and no energy is required cofactors such as ATP or NAD. Professor Yang brave group found chiral carbon quantum chiral carbon cysteine ​​analog may be synthesized to achieve regulation of topoisomerase I DNA topology, and the regulation of expression chiral dependent differences: D- carbon quantum dot (D-CDs) can be efficiently converted to super-coiled plasmid DNA having a cutout open loop conformation, L- carbon quantum dots (L-CDs) catalytic conversion of carbon is much lower than D- quantum dots. Mechanism found that chiral carbon quantum may be embedded between the base of the inserted DNA double helix structure, and efficiently catalyze the formation of reactive oxygen species, resulting in oxidative cleavage of single-stranded DNA phosphate backbone, DNA change from a supercoiled conformation open loop conformation . Molecular dynamics simulation further demonstrated with respect to L- cysteine, D- cysteine ​​DNAMore may be formed between hydrogen and lower binding free energy, D-CDs opposite L-CDs with DNA having a stronger binding force to exhibit higher catalytic activity and regulation. Taking into account the topology of DNA has important influence on functions of the cell-free protein expression system, the plasmid DNA to be expressed green fluorescent protein (p-eGFP) as a model, the chiral carbon over the quantum dot processing spiral function expression plasmid DNA. Plasmid continue normally found GFP expression chiral carbon quantum dot processing, expression and protein production rate than the control group and having a slightly greater. This finding suggests that the plasmid DNA double helix gap little effect on its transcription. In the process of transcription, DNA duplex unwinding inside the RNA polymerase, the RNA synthesis, RNA polymerase moves forward along the DNA duplex, RNA polymerase removed recombine into double stranded DNA structure, the entire process of transcription in, DNA double-stranded structure is still intact, but it will not break because there are gaps in the transcription process. In addition, the authors speculate that since the DNA is free to rotate on both sides of the notch is not formed in the supercoiled DNA transcription process, and therefore is more conducive to the transcription process. This study reveals the influence of the chiral C in quantum their catalytic properties organisms with carbon quantum dot regulation of DNA conformation to explore the effect of DNA conformation and mechanisms of its gene function, DNA conformation relationships and transcription life processes of understanding has important implications, has potential applications in the field of protein engineering and gene editing. Original link: https: //www.onlinelibrary.wiley.com/doi/10.1002/anie.202002904