Behavior of α, β tubulin in DMSO-containing electrolytes

• Author(s) / Creator(s)

  • Aarat Pratyaksh Kalra, Piyush Kar, Jordane Preto, Vahid Rezania, Aristide Dogariu, John D Lewis, Jack Tuszynski, Karthik Shankar

• α, β -tubulin is a cytoskeletal protein that forms cylindrical structures termed microtubules, which are crucial to the cell for a variety of roles. Microtubules are frequently modelled as one-dimensional bionanowires that act as ion transporters in the cell. In this work, we used dynamic light scattering (DLS) to measure the hydrodynamic diameter of tubulin in the presence of a polar aprotic co-solvent. We found that the hydrodynamic diameter increased with increasing DMSO volume fraction, almost doubling at 20% DMSO. To evaluate if this was due to an enlarged solvation shell, we performed reference interaction site model (RISM) simulations and found that the extent of solvation was unchanged. Using fluorescence microscopy, we then showed that tubulin was polymerization competent even in the presence of colchicine, and thus inferred the presence of oligomers in the presence of DMSO, which points to its mechanism of action as a microtubule polymerization enhancer. Tubulin oligomers are known to form when microtubules depolymerize and are controversially implicated in microtubule polymerization as well. We show that DLS may be used to monitor early-state microtubule polymerisation and is a viable alternative to fluorescence and electron microscopy-based methods. Our findings showing that DMSO causes tubulin oligomerization are thus of critical importance, both for creating bio-inspired nanotechnology and determining its biophysical roles in the cell.

• Date created

  2019-06-15

• Subjects / Keywords

  • microtubules
  • solvation dynamics
  • tubulin dimers
  • bionanowires

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-w7n0-qa06

• License

  Attribution-NonCommercial 4.0 International