Microgravity - Science and Technology

, Volume 18, Issue 3, pp 91–94

Diffusion coefficient of the protein in various crystallization solutions: The key to growing high-quality crystals in space


    • Confocal Science Inc.
  • Sachiko Takahashi
    • Confocal Science Inc.
  • Mari Yamanaka
    • Confocal Science Inc.
  • Izumi Yoshizaki
    • Japan Aerospace Exploration Agency
  • Masaru Sato
    • Japan Aerospace Exploration Agency
  • Satoshi Sano
    • Japan Aerospace Exploration Agency
  • Moritoshi Motohara
    • Japan Aerospace Exploration Agency
  • Tomoyuki Kobayashi
    • Japan Aerospace Exploration Agency
  • Susumu Yoshitomi
    • Japan Aerospace Exploration Agency
  • Tetsuo Tanaka
    • Japan Aerospace Exploration Agency
  • Seijiro Fukuyama
    • Advanced Engineering Service

DOI: 10.1007/BF02870387

Cite this article as:
Tanaka, H., Takahashi, S., Yamanaka, M. et al. Microgravity Sci. Technol (2006) 18: 91. doi:10.1007/BF02870387


The diffusion coefficients of lysozyme and alpha-amylase were measured in the various polyethylene glycol (PEG) solutions. Obtained diffusion coefficients were studied with the viscosity coefficient of the solution. It was found that the diffusion process of the protein was suppressed with a factor of vγ, where ν is a relative viscosity coefficient of the PEG solution. The value of γ is −0.64 at PEG1500 for both proteins. The value increased to −0.48 at PEG8000 for lysozyme, while decreased to −0.72 for alpha-amylase. The equation of an approximate diffusion coefficient at certain PEG molecular weight and concentration was roughly obtained.

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© Z-Tec Publishing 2006