两种海蜇毒素的分子标记研究

采用聚丙烯酰胺凝胶电泳技术研究了8种同工酶在海蜇的刺胞和中胶层的表达特异性,利用RAPD技术对海蜇刺胞组织的DNA标记进行研究。结果表明,作为生物体防御清除自由基的SOD,在刺胞和中胶层均有表达。而与酯类化合物代谢相关的EST、维持细胞正常的能量代谢的ATPase,能在海蜇和口冠海蜇的刺胞中表达,而不能在中胶层中表达,所以,EST和ATPase可作为刺胞毒素的分子标记。碳水化合物代谢中重要的酶类MDH和ADH、清除细胞内H2O2的POD、催化磷酸单酯水解的重要酶类(与磷脂的转移、消化、吸收等活动密切相关的)ACP、在体外碱性环境下能水解有机磷脂键而产生一个有机基团和无机磷酸根的ALP,这5种酶仅在毒性较强的口冠海蜇刺胞中表达,MDH和ACP活性很高,在毒性相对较弱的海蜇刺胞中不表达。所以,这5种酶可作为海蜇毒性强弱的标记。以两种海蜇刺胞DNA为模板,S11、S32、S38、S95等4个随机引物的RAPD谱图差异明显,亦可作为毒素强弱的间接分子标记。

THE MOLECULAR MARKERS OF THE TOXIN FROM TWO JELLYFISH SPECIES

This paper presents the molecular markers of toxin in cnidoblast of two jellyfish species: Stomopholus meleagris and Rhopilema esculentum. To study physiological, biochemical and pharmacological characteristics of the cnidoblast animal, eight types of jellyfish isozyme were studied with vertical polyacrylamide gel electrophoresis. The results showed that superoxide desmutase (SOD), a defensive enzyme against superoxide anion radical, was expressed in both cnidoblast and mesoglea. Esterase (EST) that related to ester metabolism and adenosine triphosphatase (ATPase) that involved in energy cycle of normal cell can only detected in cnidoblast and not in mesoglea, suggesting that both of the enzymes may be used as molecular marker for the existence of toxin. The other five types of enzymes, including malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), peroxidase (POD), acid phosphatase (ACP) and alkaline phosphatase (ALP), were found only in cnidoblast of Stomopholus meleagris, but Rhopilema esculentum. Of them, MDH and ACP showed very high activity. MDH and ADH are two of important enzymes in the metabolism of carbohydrate; POD is an important enzyme to remove H_2O_2 in cell; ACP catalyzes the hydrolysis of phosphomonoester and therefore is closely related to transfer, digestion and absorption of phospholipid. These results indicate that these five types of enzymes may be used to indicate the potency of toxin because the toxin in S.meleagris is more toxic than that in R.esculentum. RAPD was done using DNA from two types of jellyfish as a template, and a significant difference exist between the profiles of theirs.