講演情報
[16a-P01-10]Optical trapping-induced deformation of protein layer at solution surface and its contour mapping by polystyrene microparticles
〇(M2)Chia-Hong Su1, Mu-En Li1, Po-Wei Yi1, Hiroshi Masuhara1 (1.Nat'l Yang Ming Chiao Tung Univ.,Taiwan)
キーワード：
Cooperative optical trapping、Protein assembly formation、Surface deformation
Optical trapping has nowadays become a mature technology, and people can manipulate small molecules or particles by introducing the focused laser beam. This innovative technique has also been applied to biological research field. Moreover, most of the study focuses on the protein assembly formation, from crystallization and aggregation to protein droplet. Consequently, figuring out the morphology of the protein assembly during the optical trapping process is of significant important. Our group has reported that protein clusters form an assembly along air/solution interface, which is much larger than laser focal size1.
In this report, we first show how protein lysozyme assembles at the solution surface just by leaving the solution. The lysozyme adsorption layer containing a fluorescent probe becomes thicker, probably driven by the hydrophilic nature of its amino residues, as fluorescence intensity is increased with the pending time. Lysozyme adsorption multilayer rapidly formed within 20 min (Fig.1 Left), giving a viscous multilayer (Fig.1 Right)2. Added polystyrene microparticles (PS MPs) float on the solution surface due to buoyancy (Fig.2 Left), which helps us to figure out the surface deformation. Upon switching on the trapping laser, the distribution of the PS MPs was quickly changed, and they were focused or defocused showing more bright or dark individual MP image (Fig.2 Right). We consider that protein multilayer film receives enough gradient and scattering force to deform the surface morphology. Now we develop a correction method to estimate the height of PS MPs based on the transmission image and its brightness of each PS MP. We will show a contour map of the lysozyme film and its dynamic change upon optical trapping and elucidate the surface deformation including the levitation effect.
In this report, we first show how protein lysozyme assembles at the solution surface just by leaving the solution. The lysozyme adsorption layer containing a fluorescent probe becomes thicker, probably driven by the hydrophilic nature of its amino residues, as fluorescence intensity is increased with the pending time. Lysozyme adsorption multilayer rapidly formed within 20 min (Fig.1 Left), giving a viscous multilayer (Fig.1 Right)2. Added polystyrene microparticles (PS MPs) float on the solution surface due to buoyancy (Fig.2 Left), which helps us to figure out the surface deformation. Upon switching on the trapping laser, the distribution of the PS MPs was quickly changed, and they were focused or defocused showing more bright or dark individual MP image (Fig.2 Right). We consider that protein multilayer film receives enough gradient and scattering force to deform the surface morphology. Now we develop a correction method to estimate the height of PS MPs based on the transmission image and its brightness of each PS MP. We will show a contour map of the lysozyme film and its dynamic change upon optical trapping and elucidate the surface deformation including the levitation effect.