Velocity Control of Microtubules with High Spatial Resolution on an Au-coated Surface with an SU-8 Thermal Isolation Layer

Abstract

The velocity of microtubules gliding on a kinesin-coated surface has been modulated by changing the rate of ATP hydrolysis, temperature, and buffer conditions. Conventional methods have not realized velocity control with high spatial resolution. Here, we propose a method to selectively determine the gliding velocity of microtubules with the help of light irradiance on an Au-coated Si surface. A part of the Au layer was thermally isolated by an underneath coating of SU-8 photoresist, which was employed as a thermal insulation layer. In the area without SU-8, the Au layer was deposited directly on the Si substrate. Irradiation of 13.5 W/cm² controlled the velocity with approximately 40 µm of spatial resolution in the SU-8 coated area, resulting in a velocity of 0.80 ± 0.10 µm/s, whereas in the non-coated area the velocity was 0.62 ± 0.05 µm/s.