[17p-A32-1~13] 3.1 Basic optics and frontier of optics

4:30 PM - 4:45 PM JST(7:30 AM - 7:45 AM UTC)

[17p-A32-12] Spatiotemporal control of a single liquid-like condensate formation of α-synuclein by optical trapping at solution surface

〇Keisuke Yuzu^1,2, Ching-Yang Lin¹, Po-Wei Yi¹, Chih-Hao Huang¹, Eri Chatani², Hiroshi Masuhara¹ (1.Nat'l Yang Ming Chiao Tung Univ., 2.Kobe Univ.)

Keywords:

optical trapping,protein condensate,amyloid fibrils

The laser has been an indispensable tool since its invention in 1960, and one of the most interesting phenomena is optical trapping, a technique to manipulate micro- and nanoparticles by mechanical force with a focused laser. We have studied on optical trapping-induced new phenomena of nanoparticles, in particular optically evolved assembly on solution surface, where nanoparticles assemble and grow to become much larger beyond the laser focus. However, trapping protein molecules is typically challenging because optical forces loaded on them are too weak due to their small size. Nonetheless, we have recently found that lysozyme form disk-like assembly in a supersaturated condition by optical trapping at the solution surface. Here, by applying a focused laser to the solution surface, we have demonstrated the spatiotemporal formation of a single liquid-like condensate of α-synuclein in its unsaturated condition. The fluorescent dye-labeled imaging showed that the optically induced condensate has a gradient of protein concentration from the center to the edge, suggesting that it is fabricated through optical pumping-up of the α-synuclein clusters and the expansion along the interface. Furthermore, microscopic and spectroscopic analyses have revealed the stepwise evolution and aging of the condensate and the eventual formation of amyloid fibrils. This finding highlights the effectiveness of optical trapping for spatiotemporal control of protein condensate formation.