An Optical Device Driven by Motor Protein

Abstract

Here, we developed a motor-protein-driven optical device. To design the device, we focused on body color change of fish. This phenomenon is caused by melanophore cells, which contains thousands of pigment granules. In a melanophore, pigments are transported by motor proteins along radially arranged microtubules. Thus, the distribution of pigments in a melanophore (i.e. color of a melanophore) is changed. By mimicking this molecular system, we tried to make an artificial melanophore from minimal components: motor proteins, microtubules and pigment granules. Nuclei of microtubule assembly were attached to micro-fabricated dot patterns, and microtubules were grown from them, which produced a radial array of numerous microtubules (Figure A). When stained micro-particles with flagellar dynein were introduced, those particles were transported along radially arranged microtubules and were gathered by ATP addition, which resulted in changing color patterns of each artificial melanophore (Figure B, C). Furthermore, we succeeded in drawing desired pictures on “bio-display”, a display that one pixel is equivalent to one artificial melanophore, by adding ATP to particular pixels with caged ATP. This study has shown that a novel optical device can be constructed by arranging microtubules and motor protein molecules.