Rapid localized crystallization of lysozyme by laser trapping

Abstract

Confining protein crystallization to a millimetre size was achieved within 0.5 h after stopping 1 h intense trapping laser irradiation, which shows excellent performance in spatial and temporal controllability compared to spontaneous nucleation. A continuous-wave near-infrared laser beam is tightly focused into a glass/solution interfacial layer of a supersaturated buffer solution of hen egg-white lysozyme (HEWL). The crystallization is not observed during laser trapping, but initiated by stopping the laser irradiation. The generated crystals are localized densely in a circular area with a diameter of a few millimetres around the focal spot and show specific directions of the optical axes of the HEWL crystals. To interpret this unique crystallization, we propose a mechanism that nucleation and the subsequent growth take place in a highly concentrated domain consisting of HEWL liquid-like clusters after turning off laser trapping.

Cooperative Optical Trapping of Polystyrene Microparticle and Protein Forming a Submillimeter Linear Assembly of Microparticle

“…It was achieved in a few hours after stopping the laser irradiation, and the resultant crystals were distributed in a circle area with a diameter of a few millimeters around the focal spot. We considered that lysozyme was collected at and around the focus like in the present experiment, but it took a long time for lysozyme to find mutual associative orientation, triggering the nucleation . It was reported for lysozyme in solution by Tsuboi et al that the crystallization was induced through its aggregation after some lag time .…”

“…We considered that lysozyme was collected at and around the focus like in the present experiment, but it took a long time for lysozyme to find mutual associative orientation, triggering the nucleation. 42 It was reported for lysozyme in solution by Tsuboi et al that the crystallization was induced through its aggregation after some lag time. 27 Previously, we reported the lysozyme assembly formation in solution by analyzing optical trapping-induced crystal growth of a spontaneously prepared lysozyme crystal.…”

A Single Large Assembly with Dynamically Fluctuating Swarms of Gold Nanoparticles Formed by Trapping Laser

“…Assemblies of metallic and semiconductor nanoparticles are studied with optical spectroscopy upon laser trapping. These assemblies show the energy shift of electronic transition from that of individual nanoparticles. − When multiple metallic nanoparticles diffusing in solution are trapped at the irradiated area, the nanoparticles are optically bound and arranged in ordered structure depending on the laser polarization, wavelength, etc. − Apart from nanoparticles, the nucleation of molecular systems (amino acids) and the resultant crystal growth are possible even from unsaturated solution by laser trapping at a solution interface. − By control of the laser polarization, the resultant crystal morphology is biased to certain forms. , The protein growth rate of lysozyme can be controlled by laser trapping, , and amyloid fibril formation of cytochrome C can be spatiotemporally induced by laser trapping . In general, the nanoparticles and molecules are trapped, concentrated at the focus, and distributed outside of the focus, giving their clusters, assemblies, and even crystals.…”

“…40−42 By control of the laser polarization, the resultant crystal morphology is biased to certain forms. 41,42 The protein growth rate of lysozyme can be controlled by laser trapping, 43,44 amyloid fibril formation of cytochrome C can be spatiotemporally induced by laser trapping. 45 In general, the nanoparticles and molecules are trapped, concentrated at the focus, and distributed outside of the focus, giving their clusters, assemblies, and even crystals.…”

Using optical tweezing to control phase separation and nucleation near a liquid–liquid critical point

“…Thus, LIPS is likely to be related to a string of recent laserinduced nucleation experiments claiming to use optical trapping of clusters, 15,17,19,61,62,[70][71][72][73][74] although these experiments could only be carried out at air-solution interfaces, implying that evaporation, Marangoni effects, and thermophoresis may play important roles as well. A repeat of these experiments in the bulk would be worthwhile, bearing in mind the possibility of a hidden liquidliquid critical point enhancing concentration fluctuations.…”