Crystal Growth of Lysozyme Controlled by Laser Trapping

Abstract

ABSTRACT:We demonstrate the growth of a tetragonal crystal of hen egg-white lysozyme (HEWL) in D 2 O buffer solution controlled by laser trapping with a focused continuous-wave (CW) near-infrared (NIR) laser beam. The focal spot was located at 10 μm away from the edge of the target crystal that was generated spontaneously, and the crystal growth was observed although the focal spot size was much smaller than the distance. The growth rate of (101) and {110} faces of the tetragonal crystal was examined with various laser powers and polarizations. The rate observed under the irradiation was much different from those in spontaneous growth, namely, the growth rate of the {110} face showed a large decrease or increase depending on the irradiation time. The dynamics and mechanism of this unusual crystal growth behavior is discussed from the viewpoint of a large stable domain formation of the HEWL liquidlike clusters through liquid nucleation and growth and by considering the anisotropy of the cluster domain. L aser-induced nucleation and crystal growth have received much attention over the past two decades because of their wide applicability, polymorph selectivity, and spatial-temporal controllability.

Whirl-enhanced continuous wave laser trapping of particles

“…35 Nanoplasmonics has extended the field of optical trapping down to the nanometer scale with exciting possibilities for studying single proteins and nanoparticles. [37][38][39][40][41] In this work we report on microdroplet formation and microcrystal growth under cw laser light illumination in a new solute-solvent system as compared to that reported by Yuyama et al 34 However, to observe the qualitatively the same phenomenon we used light intensity roughly six orders of magnitude lower than that used in the quoted work. In this case trapping is approximately 3000Â more efficient than the conventional one and particles of 12 nm in size and even single proteins have been trapped with double-nanohole (DNH) structures with 1-10 mW power.…”

Role of Impurity Nanoparticles in Laser-Induced Nucleation of Ammonium Chloride

“…[15][16] The main advantage of NPLIN is that it appears to be similar to homogeneous 2 nucleation: it requires only solute and solvent, occurs in the bulk of the solution, and there is no chemical damage to molecules. A variant of NPLIN based on optical trapping using continuouswave laser light has been demonstrated; [17][18] in the remainder of this article, however, we will deal specifically with pulsed laser-induced nucleation.…”

Marangoni effect visualized in two-dimensions Optical tweezers for gas bubbles

“… 28 reported on how using optically controlled bubble microrobots a particle microassembly can be accomplished. Several papers of Matsuhara group 29 30 31 dealt with laser induced flows and crystal formation under laser beam. Lin et al .…”