A novel thermophilic lysozyme from bacteriophage φIN93

The lysozyme of bacteriophage phi IN93 was purified to apparent homogeneity with Carboxymethyl Sepharose and Hydroxyapatie columns from lysates of the phage grown on Thermus aquaticus TZ2. The enzyme is a single polypeptide chain with a molecular weight of 33,000. From the determined N-terminal amio acids of the enzyme, the locus of the gene was specified on a phi IN93 genome. The enzyme was not similar to egg white lysozyme. T4 phage lysozyme, or lambda phage lysozyme. The enzyme, pIN93 lysozyme, was found to be a novel type of thermophilic lysozyme, which lyses specifically Thermus sp. cells, and exhibited conspicuous thermal stability at 95 degrees C for 1 h in the presence of beta-mercaptoethanol. (C) 2008 Elsevier Inc. All rights reserved.