Tris(hydroxymethyl)aminomethane-modified magnetic microspheres for rapid affinity purification of lysozyme

A novel affinity purification method for lysozyme (LZM) based on functionalized magnetic microspheres was developed. Tris(hydroxymethyl)aminomethane (Tris)-modified magnetic microspheres with specific affinity toward LZM were prepared using Tris as ligand and silica-coated magnetic microshperes as support. Transmission electron microscopy and magnetic property measurement results showed that the Tris-modified magnetic microspheres have a very good core-shell structure and high magnetization. The maximum binding capacity of LZM was about 108.6 mg/g magnetic microspheres. LZM purified from chicken egg white had high purity and well-maintained activity of 8140 U/mg. This magnetic-mediated LZM purification strategy has advantages of high efficiency, low cost and easy operation. (C) 2010 Elsevier B.V. All rights reserved.