Protein crystal growth in space, past and future

Early hydration of Portland cement studied under microgravity conditions

“…So far, almost all experiments relating to crystal growth under microgravity have been performed with proteins ($200 different samples on 39 US Space Shuttle flights). Contrary to normal gravity, highly regular crystals resulting from slower growth were obtained and in many cases it was possible to determine the crystal structure via single crystal X-ray diffraction [12,13]. Interestingly, the growth of only very few inorganic minerals has been studied so far in microgravity environment, among them NaCl [14], thermoelectric Bi 2 Se 0.21 Te 2.79 [15] and calcium phosphate, Ca 5 (PO 4 ) 3 OH [16].…”

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

“…Crystallization of protein and small-molecule materials from solution has been studied in a number of external fields, such as acoustic [1], magnetic [2], electric [3], hydrodynamic [4], and [5,6]. The effects that these fields have on the growth processes of crystals of the various studied materials and the consequences for the quality of the crystals are, in most cases, well understood.…”

Using magnetic fields to control convection during protein crystallization—analysis and validation studies

“…A gradient of concentration is produced from the far field that is near saturation to the depletion zone and, in the absence of fluid convection, material is transported toward the crystal by diffusion. In a gravitational field, the solute gradient can give rise to solutal convection that often interferes with the quality of the growth process and has prompted researchers to take advantage of the weightless environment of space to reduce these motions [1][2][3]. Magnetic fields have been used to damp convective motion in conducting melts [4] by making use of the Lorenz force in a static magnetic field.…”