Formation of protein crystals (orthorhombic lysozyme) in quasi-microgravity environment obtained by superconducting magnet

Yin, Da‐Chuan; Wakayama, Nobuko I.; Harata, Kazuaki; Fujiwara, M.; Toko, Kiyoshi; Wada, Hitoshi; Nakabayashi, Nobuo; Arai, Shigeki; Huang, Weidong; Tanimoto, Yoshifumi

doi:10.1016/j.jcrysgro.2004.05.106

Cited by 54 publications

(44 citation statements)

References 15 publications

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“…Here, we will show that magnetic forces can be used to simulate variable gravity environments for paramecia. This work builds on previous studies using magnetic levitation (14)(15)(16) to simulate zero gravity for protein crystallization (17,18) and fluid dynamics experiments (19) and magnetic forces to alter gravitropism in plants (20). In an earlier report (21), a magnetic force buoyancy variation technique (MFBV) was introduced to vary the apparent weight of immobile cells with magnetic forces.…”

mentioning

confidence: 93%

Swimming Paramecium in magnetically simulated enhanced, reduced, and inverted gravity environments

Guevorkian

Valles

2006

Proc. Natl. Acad. Sci. U.S.A.

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Earth's gravity exerts relatively weak forces in the range of 10 -100 pN directly on cells in biological systems. Nevertheless, it biases the orientation of swimming unicellular organisms, alters bone cell differentiation, and modifies gene expression in renal cells. A number of methods of simulating different strength gravity environments, such as centrifugation, have been applied for researching the underlying mechanisms. Here, we demonstrate a magnetic force-based technique that is unique in its capability to enhance, reduce, and even invert the effective buoyancy of cells and thus simulate hypergravity, hypogravity, and inverted gravity environments. We apply it to Paramecium caudatum, a single-cell protozoan that varies its swimming propulsion depending on its orientation with respect to gravity, g. In these simulated gravities, denoted by f gm, Paramecium exhibits a linear response up to fgm ‫؍‬ 5 g, modifying its swimming as it would in the hypergravity of a centrifuge. Moreover, experiments from f gm ‫؍‬ 0 to ؊5 g show that the response is symmetric, implying that the regulation of the swimming speed is primarily related to the buoyancy of the cell. The response becomes nonlinear for f gm >5 g. At fgm ‫؍‬ 10 g, many paramecia ''stall'' (i.e., swim in place against the force), exerting a maximum propulsion force estimated to be 0.7 nN. These findings establish a general technique for applying continuously variable forces to cells or cell populations suitable for exploring their force transduction mechanisms.buoyancy ͉ force ͉ gravikinesis ͉ levitation ͉ microorganism

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mentioning

confidence: 93%

Swimming Paramecium in magnetically simulated enhanced, reduced, and inverted gravity environments

Guevorkian

Valles

2006

Proc. Natl. Acad. Sci. U.S.A.

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“…Although experiments carried out in space have produced good results, Earth-based methods always have obvious attractions (Helliwell & Chayen, 2007). The magnetic field (Sazaki, 1997;Yin et al, 2004Yin et al, , 2008 and gel methods (García-Ruiz et al, 2001) have been used to reduce the effect of convective flow on protein crystallization. Microfluidics also can provide the advantages of microgravity on Earth.…”

Section: Introductionmentioning

confidence: 99%

Design and application of a microfluidic device for protein crystallization using an evaporation-based crystallization technique

Wang

Oberthür

et al. 2011

J Appl Cryst

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A new crystallization system is described, which makes it possible to use an evaporation-based microfluidic crystallization technique for protein crystallization. The gas and water permeability of the used polydimethylsiloxane (PDMS) material enables evaporation of the protein solution in the microfluidic device. The rates of evaporation are controlled by the relative humidity conditions, which are adjusted in a precise and stable way by using saturated solutions of different reagents. The protein crystals could nucleate and grow under different relative humidity conditions. Using this method, crystal growth could be improved so that approximately 1 mm-sized lysozyme crystals were obtained more successfully than using standard methods. The largest lysozyme crystal obtained reached 1.57 mm in size. The disadvantage of the good gas permeability in PDMS microfluidic devices becomes an advantage for protein crystallization. The radius distributions of aggregrates in the solutions inside the described microfluidic devices were derived fromin situdynamic light scattering measurements. The experiments showed that the environment inside of the microfluidic device is more stable than that of conventional crystallization techniques. However, the morphological results showed that the protein crystals grown in the microfluidic device could lose their morphological stability. Air bubbles in microfluidic devices play an important role in the evaporation progress. A model was constructed to analyze the relationship of the rates of evaporation and the growth of air bubbles to the relative humidity.

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“…Our group has studied magnetic orientation of organic crystals [8] and carbon nanotubes [9]. By using quasi-microgravity generated by magnetic force, X-ray crystallographic quality of lysozyme crystals is improved [10]. Although, from the above-mentioned studies, it is shown that a high magnetic field is a useful tool for controlling crystallization, there still remain many problems to be solved as to the role of magnetic fields in crystallization.…”

Section: Introductionmentioning

confidence: 99%

“…There are a few reports on the effects of vertical magnetic fields on crystal growth [10][11][12][13], since the vertical magnetic force is expected to vary effective earth's gravity, which is a cause of natural convection of solution. In the case of a horizontal magnetic field, the magnetic force is perpendicular to the gravity.…”

Section: Introductionmentioning

confidence: 99%

Influences of high magnetic field on glycine crystal growth

Sueda

Katsuki

Fujiwara

et al. 2006

Science and Technology of Advanced Materials

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The effects of horizontal high magnetic field (8 T) on both the orientation of the a-form glycine crystal and the growth rate were studied. The aform glycine crystal is oriented in the high magnetic field in such a way that its crystallographic c-axis is at about 458 with the direction of magnetic field. This orientation is explained by the magnetic susceptibility anisotropy of the crystal structure. The crystal growth rate in the c-axis direction decreases by about 20% in a magnetic field (8 T). Mechanisms of the magnetic field effect on the growth rate are discussed. q

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Formation of protein crystals (orthorhombic lysozyme) in quasi-microgravity environment obtained by superconducting magnet

Cited by 54 publications

References 15 publications

Swimming Paramecium in magnetically simulated enhanced, reduced, and inverted gravity environments

Swimming Paramecium in magnetically simulated enhanced, reduced, and inverted gravity environments

Design and application of a microfluidic device for protein crystallization using an evaporation-based crystallization technique

Influences of high magnetic field on glycine crystal growth

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