Isolation and characterization of a novel two-component hemolysin, erylysin A and B, from an edible mushroom, Pleurotus eryngii

A novel two-component hemolysin, erylysin A and B (EryA and EryB), was isolated from an edible mushroom, Pleurotus eryngii. Hemolytic activity was exhibited only by the EryA and EryB mixture. EryA showed one band at 15 kDa on SDS-PAGE while EryB showed two bands at 15 kDa (EryB1) and 37 kDa (EryB2). MALDI-TOF MS showed that the molecular masses of EryA, EryB1 and EryB2 were 14,945 Da, 14,593 Da and 37,417 Da, respectively. EryA and EryB were very similar to pleurotolysin A and B in terms of molecular mass, and the N-terminus and inner sequences. At pH 7.2, EryA exists as a homodimer whereas EryB exists as a heterodimer of B1 and B2. CD spectrum analysis showed Tm values of 47 °C and 37 °C for EryA and EryB, respectively. EryB was particularly unstable.