AVS 70 Session BI-TuA: Future of Biointerface Science Collection (ALL-INVITED SESSION)

The comprehension of proteins and nucleic acid chains, along with their interactions, is vital in contemporary biochemistry and molecular biology. These molecules can induce biological phase separation, resulting in the formation of membraneless organelles (MLOs) within cells. Consequently, understanding their structure is key, as it directly influence their ultimate behaviour. Moreover, external factors or interactions can directly impact their characteristics and final function, as evidenced in degenerative diseases like amyotrophic lateral sclerosis (ALS) or frontotemporal dementia (FTD).

In this context, we present the employment of Coherent Anti-Stokes Raman spectroscopy (CARS) as an appropriate method to characterize the changes happening over time in condensates. By examining the fingerprint region of nucleic acids, we can determine the biological interactions taking place. In designed DNA condensate model systems, ssDNA to dsDNA hybridization or salt effects can be monitored in the final assembled conformation. For proteins, their secondary structure can be elucidated, ranging from an ordered α-helix or β-sheet to a disordered random coil. Finally, protein-RNA interactions can be also characterized, as for TDP-43 low complexity domain (TDP43-LCD) and RNA. While introducing further complexity, the Raman shifts observed in specific regions of the formed condensates can indicate the RNA’s effect on the protein, including secondary structure control.