Weixiang Chen

PhD Student
Associate member of the GRK2516
Group: Prof. Andreas Walther, JGU Chemistry
Contact: E-mail, Web

Research Project: Experiments
DNA Based Synthetic Protocells

Biomolecular condensates are membraneless organelles formed via liquid-liquid phase separation (LLPS) in cells. They represent individual compartments and adsorb molecules resulting in local enrichment to carry out different physicochemical reactions for the regulation of cellular functions. Typically, biomolecular condensates are composed of proteins and nucleic acids. Recently, we have discovered that synthetic DNA polymers with specific sequences are also capable of undergoing LLPS to form complex coacervates. We thus want to exploit these DNA based coacervates to perform life-like functions as synthetic mimics to biomolecular condensates.
Currently, I am working on producing long chain DNA polymers with synthetic tools such as rolling circle amplification (RCA) and terminal deoxynucleotidyl transferase (TdT) synthesis. With RCA, I am able to engineer the sequences of the long chain DNA polymers by a template directed synthesis, so that DNA polymers with barcode domains can be obtained that are addressable with complementary oligonucleotides. However, it is not possible to control the chain length precisely with this method. A broad distribution of the molecular weight of the DNA polymers can not be avoided. With such polymers of broad distribution, it is not trivial to generate coacervates of desired size, due to the differences in the cloud points of polymers with different chain lengths. By a series of optimization, I have successfully obtained DNA condensates with large size ranging from 10 to 30 μm. For a next step, I will utilize DNA nanotechnology to further construct specific structures within the condensates, e.g., artificial cytoskeleton.

Fig. 1 Long chain DNA polymers synthesized via RCA undergo LLPS forming core shell DNA condensates.