Effects of a magnetic field and magnetization force on protein crystal growth. Why does a magnet improve the quality of some crystals?

Abstract

Probable reasons why some protein crystals grown in a magnet exhibited better quality than control are discussed as follows. (1) Sedimenting three-dimensional nuclei are able to have the same orientation as the underlying, mother crystal into which the nuclei merge. (2) Protein solution may become more viscous, leading to reduction of convection. (3) If an upward force is generated by use of an inhomogeneous magnetic field, the effects of the density differences can be made less significant, causing the reduction of natural convection and the retardation of crystal sedimentation.

Technique for High-Quality Protein Crystal Growth by Control of Subgrain Formation under an External Electric Field

“…However, the growth of high-quality single crystals of proteins is difficult, which is an impediment to accurate elucidation of the 3D structures of protein molecules. Therefore, the establishment of crystallization techniques to obtain high-quality single crystals of proteins has been intensively pursued using magnetic fields [1][2][3][4][5][6][7][8], microgravity [9][10][11][12][13][14][15][16], electric fields [17][18][19][20][21], solution flow [22][23][24][25] and gel as a growth host media [26][27][28][29][30][31][32]. In this article, the improvement of the crystal quality of tetragonal hen egg white (HEW) lysozyme crystals as a model protein is demonstrated by applying an external electric field.…”

Enhancement and suppression of protein crystal nucleation due to electrically driven convection

“…Thus, the suppression of solution convention in the microgravity environment aboard spacecraft has served as the basis for elucidation of the role of the solute and impurity transport towards the interface for the growth and quality of protein and small molecule crystals [7][8][9]. Magnetic fields have been used to understand the role of molecular ordering in the crystallization processes [10].…”

Atomic structure of a CK2α human kinase by microfocus diffraction of extra‐small microcrystals grown with nanobiofilm template

“…Among these studies there are many attempts to understand better the physical aspects of crystal nucleation and growth as well as to improve crystal quality [Carter, 1997;Rayment, 1997Rayment, , 2002Garcia-Ruiz and Moreno, 1997;Huang et al, 1999;Li et al, 1999;Bunick et al, 2000;Pjura et al, 2000;Nollert et al, 2002;Sauter et al, 2002]; crystallization was also studied in magnetic [Ataka and Wakayama, 2002], electric or ultrasonic fields [Taleb et al, 1999;Nanev and Penkova, 2001], under high pressure [Suzuki et al, 2002] and high temperature [Han and Lin, 2000] centrifugation [Pitts, 1992;Lenhoff et al, 1997], levitation [Chung and Trinh, 1998], microgravity [McPherson, 1997;Borgstahl et al, 2001].…”