Function Of Acid Phosphatase During The Autolysis Of Sea Cucumber Induced By UV Irradiation

The purification and property of acid phosphatase obtained from the body wall of sea cucumber were studied firstly in this paper. After induced by UV radiation, the change of acid phosphatase in the body wall and the gut was also studied.It was purified to homogeneity by ammonium sulfate precipitation, chromatography with DEAE-Sepharose CL-6B, Sephacryl S-100and TSK GEL-4000. The molecular weight of the purified enzyme was147.9kDa estimated by SDS-PAGE. The enzyme showed optimum activity at pH4.0and50℃with p-nitrophenylphosphate as substrate. The enzyme showed high stability within the range of pH2.0～5.0and thermostability was20～40℃. The enzyme activity was markedly activated by Mg2+, whereas strongly inhibited by Cu2+and Zn2+. The amino acid sequences of three segments of the purified enzyme were acquired by mass spectrometer method, which did not have any homology with previously described echinoderm acid phosphatase. The result suggested it may be a novel member of echinoderm acid phosphatase.The result of PAGE showed the type of acid phosphatases from the body wall was different from the gut. Furthermore, the acid phosphatases from gut had three isoenzymes. After the sea cucumber was induced by UV radiation, all acid phosphatases from the body wall and the gut were activited. The result of PAGE on different autolytic time indicated that the enhancement of acid phosphatase activity was caused by the activation of pre-enzyme. The grade separation of lysosome showed acid phosphatase was activited in lysosome and migrated to cytoplasm and other cellular organ in the process of autolysis. There were some association between acid phosphatase and cathepsin. Acid phosphatase could both inhibit cathepsin and maybe activated by cathepsin, so it had a little regulation during the autolysis. Further studies should be carried out on the exactly function of acid phosphatase.