Researchers identify ultrasoft properties in the DNA of blood parasites

The new insights about the parasites' special 'kinetoplast' DNA could support the development of materials in synthetic chemistry.

Microscopy and molecular simulations have led to a study which characterizes the unique DNA structures housed by single-cell parasites called Trypanosomes. The new insights about the parasites' special kinetoplast DNA (kDNA) — made of thousands of interlocking DNA circles — could support the development of materials such as topological gels in synthetic chemistry.

Trypanosome kDNA self-assembles in 2D ‘Olympic-rings­-like’ patterns, resembling a medieval chainmail. But little is known about the biophysical mechanisms determining kDNA’s formation, self-assembly and replication. 

An international team, including Dr Davide Michieletto from the School’s Institute for Condensed Matter and Complex Systems, has harnessed high-resolution imaging techniques and molecular dynamics simulations to reveal new information about kDNA’s structure.

They measured the mean number of DNA rings interlinked to any one ring is around three, and propose that these connections are regulated in vivo to ensure kDNA integrity during replication while avoiding redundant interlocks. Based on their measurements, the researchers were able to estimate that the bending rigidity of kDNAs is thousands of times smaller than that of fatty vesicles. This result means that kDNAs are expected to behave as 'ultrasoft' materials.

According to the authors, enhanced knowledge about the self-assembly of such unusual and rare structures could support the design of ultrasoft 2D materials in synthetic chemistry, such as 'topological' gels which could be made of interlocked structures rather than chemical crosslinks.