Lysozyme distributions in the shellfishes Tapes philippinarum, Meretrix lusoria, Corbiculina leana, Crassostrea gigas, Nordotis discus, scapharca broughtnii, Mytilus edulis, Anodonta japonica, Cristaria plicata, Charonia sauliae and Batillus cornutus were investigated.
Lysozyme was chromatographed on a chitin-coated cellulose column. The enzyme activity was assayed with Micrococcus lysodeikticus cells and by the ferricyanide method with glycol chitin as substrate.
Lysozyme was found in the liver and muscle of 5 shellfish species and in the gill and mucus of 4 species. High lysozyme activity was found in the whole body of M. edulis and C. plicata. The C. leana lysozyme showed maximum activity at pH 4.5 and 65°C. The enzyme remained active for 30 min up to 90°C at pH 4.8. At temperatures above 90°C, the enzyme was completely inactive. The activity of C. leana lysozyme was inhibited by incubation with Fe²⁺, Fe³⁺, Mn²⁺, Hg²⁺, Cd²⁺, Cu²⁺ and Ni²⁺ but slightly enhanced by Mg²⁺, Ba²⁺ and Zn²⁺.