title: Numerical model of protein crystal growth in a diffusive field such as the microgravity environment.
abstract: It is said that the microgravity environment positively affects the quality of protein crystal growth. The formation of a protein depletion zone and an impurity depletion zone due to the suppression of convection flow were thought to be the major reasons. In microgravity, the incorporation of molecules into a crystal largely depends on diffusive transport, so the incorporated molecules will be allocated in an orderly manner and the impurity uptake will be suppressed, resulting in highly ordered crystals. Previously, these effects were numerically studied in a steady state using a simplified model and it was determined that the combination of the diffusion coefficient of the protein molecule (D) and the kinetic constant for the protein molecule (β) could be used as an index of the extent of these depletion zones. In this report, numerical analysis of these depletion zones around a growing crystal in a non-steady (i.e. transient) state is introduced, suggesting that this model may be used for the quantitative analysis of these depletion zones in the microgravity environment.
authors.affiliation: Confocal Science Inc., Hayakawa 2nd Building 7F, 2-12-2 Iwamoto-cho, Chiyoda-ku, Tokyo 101-0032, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Susumu
authors.initials: S
authors.lastname: Sasaki
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takahashi
authors.forename: Koji
authors.initials: K
authors.lastname: Inaka
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Wada
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Yamada
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ohta
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kamigaichi
mesh_terms: D003460:Crystallization; D008962:Models, Theoretical; D009113:Muramidase / Q000737:chemistry*; D014893:Weightlessness
chemical_list: D009113:Muramidase
keywords: impurity depletion zone; microgravity; numerical model; protein crystal; protein depletion zone; transient and diffusive field; transient and homogeneous field