Effect of a high magnetic field on protein crystal growth - magnetic fieldinduced order in aqueous protein solutions

Recently, a superconducting magnet has been used to obtain better quality c rystals. The time dependence of the birefringence (Deltan) of protein solut ions caused by the application of a strong magnetic field was studied. For the solution from which crystals are easily formed, An increased with time when a uniform magnetic field of 10 T was applied, Deltan showed the tenden cy to increase with increase in the concentrations of lysozyme and NaCl. De ltan continued to increase even after shutting down the field. If the prote in solution was never exposed to the field, Deltan did not increase. The ap pearance of Deltan suggests the molecular ordering along the direction of a magnetic field in the solutions from which crystals are easily formed. The se results can be explained by considering the formation of an interlinked network of protein molecules under a high magnetic field. (C) 2001 Elsevier Science B.V. All rights reserved.