Isolation and characterization of venom from nematocysts of jellyfish Rhopilema esculentum Kishinouye

The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye. The nematocysts were isolated by autolysis and centrifugation and separated by flow cytometry. Four types of nematocysts were identified: mastigophores, euryteles, and atrichous and holotrichous isorhiza. SDS-PAGE and amino acid analyses demonstrated that most of the proteins in the nematocyst extract were between 10 kDa and 40 kDa, and that glutamic acid was the main amino acid. A hemolytic activity assay showed that the activity of the nematocyst venom (RNV) was strongest in Tris-HCl buffer (50 mmol/L, pH 7.8, 5% glycerol, 0.5 mmol/L EDTA, 0.1 mol/L NaCl). The hemolytic activity was related to protein concentration and the HU50 against chicken erythrocytes was 0.91 A mu g/mL.