Revealing and attenuating the electrostatic properties of tubulin and its polymers

• Author(s) / Creator(s)

  • Aarat P Kalra, Sahil D Patel, Boden B Eakins, Saralyn Riddell, Pawan Kumar, Philip Winter, Jordane Preto, Kris W Carlson, John D Lewis, Vahid Rezania, Jack A Tuszyński, Karthik Shankar

• Tubulin is an electrostatically negative protein that forms cylindrical polymers termed microtubules, which are crucial for a variety of intracellular roles. Exploiting the electrostatic behaviour of tubulin and microtubules within functional microfluidic and optoelectronic devices is limited due to the lack of understanding of tubulin behavior as a function of solvent composition. This work displays the tunability of tubulin surface charge using DMSO for the
  first time. Increasing the DMSO volume fractions leads to the lowering of tubulin’s negative surface charge, eventually causing it to become positive in solutions > 80 % DMSO. As determined by electrophoretic mobility measurements, this change in surface charge is directionally reversible i.e. permitting control between –1.5 cm2 (V s)-1 and + 0.2 cm2 (V s)-1. When usually negative microtubules are exposed to these conditions, the positively charged tubulin forms tubulin sheets and aggregates, as revealed by an electrophoretic transport assay. Fluorescence-based experiments also indicate that tubulin sheets and aggregates co-localize with negatively charged g-C3N4 sheets while microtubules do not, further verifying the presence of a positive surface charge. This study illustrates that tubulin and its polymers, in addition to being mechanically robust, are also electrically tunable.

• Date created

  2020-10-17

• Subjects / Keywords

  • tubulin
  • electric charge
  • protein mobility
  • zeta potential
  • solvent sensor
  • dimethylsulfoxide

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-ph2k-rk25

• License

  Attribution-NonCommercial 4.0 International