Purification and Characterization of G-type Lysozyme from Ostrich Egg White

Abstract

In this research, a G-type lysozyme from ostrich egg white (OEWL) was purified by pH precipitation (pH 4.0 and 7.0) and CM-Toyopearl 650M cation-exchange column chromatography followed by Sephadex-G75 gel filtration. The SDS-PAGE technique was used to assure the protein purity and the molecular weight. The results indicated that purified OEWL had a molecular weight of 21 kDa, confirming that the purified enzyme is lysozyme, which can digest the bacterial cell wall as a substrate. An analysis by 2D-PAGE revealed that OEWL had an isoelectric point (pI) of 9.95. Then, the OEWL was further characterized in terms of optimum pH and temperature. The OEWL showed a broad range of optimum pH at 4 and 7, while the optimal temperature was 30 °C.  Based on preliminary results, it was found that the purified G-type lysozyme from ostrich egg white exhibited a maximum specific activity of 60.23 unit/mg and showed the enzyme activity value of 1680.30 unit. Regarding these results, these OEWL revealed the potential for application and development as alternative products in preventing bacterial infection. It also exhibited the compatibility to be utilized in cosmetic products such as anti-acne gel in the future.