Optically accelerated crystallization of supramolecular protein molecules under laser trapping

摘要

Optically induced crystallization has been attracting much attention. Laser trapping is a potential approachto make the crystal of small molecules optically with spatiotemporal controllability. Tight focusing of a nearinfrared(NIR) continuous wave (CW) and/or pulse laser to the air/solution interface of amino acid/D_2Osolution can induce rapid crystallization from the focal spot[1]. Crystallization of small biological moleculessuch as amino acid is possible, however, that of large biological molecules, i.e. proteins, by laser trapping isstill difficult. Recently we have found that laser trapping with NIR CW laser at the air/solution interface of ahen egg-white lysozyme (HEWL)/D_2O solution ([HEWL] = 40 mg/mL, NaCl = 2.0 wt%, pD = 5. inducesassembly formation, many micrometer-sized liquid droplet formation and, eventually, enhancedcrystallization after liquid droplet formation/disappearance within a few hours.