Study On Relative Enzyme And SOD Character In Stichopus Japonicus Under UVA Irradiation

Sea cucumber, an important marine invertebrate, shows high nutritional and commercial values. However, sea cucumber possesses strong ability of autolysis, which leads to severe deterioration in its quality during processing, storage and transport.To enrich the sea cucumber autolysis theory, solve the problems which are caused in the processing and storage of sea cucumber autolysis. In this paper, living sea cucumber(Stichopus japonicus) were as the study objects. Under UVA irradiation, living sea cucumber body wall autolysis were induced, several factors were detected, such as the activities of acetylcholinesterase(AChE), cathepsin L(CL), superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GPx) and hydrogen peroxide(H2O2) content. Frsh sea cucumber body wall were also used to extraction crude SOD and character analyzed.The results showed that after exposure to 3 h, compared with the section exposed to UVA for 0h, some related factors sigificantly changed, the activity of CL increased about 97.75±1.71%, and the activity of AChE, SOD, CAT and GPx decreased 63.39%, 53.71±1.99%, 61.90±7.26% and 24.86±0.01%, respectively. The content of H2O2 increased about 5.8 fold.The optimum extraction conditions of crude SOD were: the pH was 4.0, the concentration of extracting buffer was 50 mmol/L, the extracting time was 6 h, the ratio of material and water was 1: 4, saturation of(NH4)2SO4 was 80-100%. The SOD had good heat resistance and best activity under pH 4.8. 3% H2O2 caused loss of SOD to live. Zn2+、Ca2+ could activate the enzyme; Ba2+ and Fe2+ stabilized the enzyme, and 1 mmol/L Fe2+ can result SOD complete loss activity.Based on the research of related enzyme activity changes in sea cucumber, it will enrich the autolysis theory and provie certain theoretical basis of storage process. As while, the study of crude SOD characterization laid a foundation for future research of properties and industrial application.