High-quality crystallization of lysozyme by magneto-Archimedes levitation in a superconducting magnet

• Published in: Journal of crystal growth Vol. 261; no. 4; pp. 557 - 565
• Main Authors: Maki, Syou, Oda, Yutaka, Ataka, Mitsuo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2004; Elsevier
• Subjects: A1. Magnetic fields; A1. X-ray topography; A2. Growth from solutions; Analytical, structural and metabolic biochemistry; B1. Gadolinium compounds; B1. Lysozyme; B2. Diamagnetic materials; Biological and medical sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Miscellaneous; Physics; Proteins; 75.20.−g; B1. Lysozyme; B2. Diamagnetic materials; 85.25.Ly; A1. X-ray topography; A1. Magnetic fields; 87.15.Da; A2. Growth from solutions; B1. Gadolinium compounds; 81.10.Dn; 81.10.−h; 87.64.−t; 81.10.-h; Diamagnetic materials; Paramagnetic materials; Crystal growth from solutions; 75.20.-g; Lysozyme; 87.64.-t Al. Magnetic fields; Enzyme; X ray topography; Experimental study; Protein; Glycosidases; Magnetic superconductors; Hydrolases; O-Glycosidases; Interface; Magnetic levitation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2003.09.033

By using gadolinium chloride as a crystallizing agent, and by applying a magnetic field of 3.8 T, we could crystallize lysozyme in a floating and containerless state. Optically, these crystals had little injury on the surface. Such flawless crystals were obtained only when they crystallized at the air–solution interface. White X-ray topography also showed that the crystals grown in a floating state contained less strain. As to why the crystals floated, we considered that magneto-Archimedes levitation occurred: lysozyme crystals are diamagnetic and the solution containing the Gd ions is paramagnetic. Owing to the difference in the magnetic property, the upward magnetic buoyancy force acting on the crystals could be enhanced, leading to levitation even in a usual superconducting magnet. This method may be used to manufacture high-quality protein crystals.