短蛸自溶中组织蛋白酶L样蛋白酶的活性及分布变化

Changes in Activity and Distribution of Cathepsin L-Like Proteases in Autolytic Octopus(Octopus ocellatus)

采用紫外线照射诱导短蛸自溶,检测腕部肌肉组织可溶性蛋白及可溶性胶原蛋白含量变化,监测内源总蛋白酶及内源组织蛋白酶L样蛋白酶活性变化,并应用免疫组织化学法揭示组织蛋白酶L样蛋白酶的组织分布变化。结果显示,短蛸经紫外线照射后,状态迟钝,机体瘫软,表皮及皮下组织发生黏液化,表明发生自溶。随着自溶时间的延长,可溶性总蛋白及可溶性胶原蛋白含量逐渐增加,表明结构蛋白发生降解;单位质量组织的内源蛋白酶总活力及组织蛋白酶L样蛋白酶活力逐渐上升;组织蛋白酶L样蛋白酶在自溶前的短蛸腕部肌肉组织中的分布具有不均一性,肌小梁中分布密集,肌纤维中分布稀疏。随着自溶的进行,酶染色位点逐渐分散、消失,表明组织蛋白酶L样蛋白酶在组织中发生了扩散。本研究表明以组织蛋白酶L样蛋白酶为代表的内源蛋白酶参与组织自溶。

The contents of water‐soluble total proteins and collagen proteins ,as well as the activities of endogenous total proteases and cathepsin L‐like proteases were determined in arm muscle of the autolytic octopus induced by ultraviolet （UV ） . Results showed that the octopus became insensitive after UV irradiation .The body of octopus became softened ,and mucoid degeneration took place in epidermis and subcutaneous tissue .The changes in external appearance indicated that autolysis took place .Along with autolysis ,the contents of water‐soluble total proteins and collagen proteins were found to be increased , indicating degradation of structural proteins .At the same time ,the activities of endogenous total proteases and cathepsin L‐like proteases tissue were increased in tissues in wnit mass .The distribution of cathepsin L‐like proteases in arm muscle of the autolytic octopus was in homogeneous . The stained spots of cathepsin L‐like proteases were dense in myocardial trabeculation ,but were relatively sparse in muscle fibers .Along with the progress of autolysis ,the stained spots of cathepsin L‐like proteases were scattered and eventually disappeared ,indicating the dispersion of cathepsin L‐like proteases in tissue .The findings indicated that the endogenous proteases , cathepsin L‐like proteases as representive , took part in the autolysis of octopus .