鱼类抗冻蛋白的研究 Ⅰ.黄盖鲽血清抗冻蛋白的特性及分离

Studies on Antifreeze Proteins of Fishes Ⅰ. Isolation and Characterization of Antifreeze Protein from the Fish Pseudopleuronectes yokohamae

本文首次报道了中国沿海鱼类中有含抗冻蛋白的鱼种存在。从产于中国黄海的黄盖鲽血清中分离提纯了抗冻蛋白,并对其进行了研究分析。黄盖鲽抗冻蛋白具有十分明显的降低血液冰点的作用,存在特征性的热滞现象。该蛋白的分子量为4500道尔顿左右,经Sephsdex G-25柱层析及高效液相色谱逆向层析法二步提纯。氨基酸组成分析结果表明它含有60％左右的丙氨酸。抗冻蛋白产生于黄盖鲽的冬季血清中,而不存在于夏季血清中。从肝脏中提取mRNA。Northern杂交证实,黄盖鲽抗冻蛋白是一类在转录水平上受到调控的蛋白。该蛋白的提纯及对其特性的研究,对研究抗冻基因的克隆及表达都具有重要的意义。

In this paper,the antifreeze protein was firstly reported ia the fish Pseudopleuranectes yotyhamae on the Chinese coast.Studies were carried out to characterize the protein.It was demonstrated that this protein could depress the serum freezing point effectively,and thermal hysteresis was observed,This protein was purified by Sephadex G-25 and HPLC C18 column,It has a molecular weight about 4500 daltons and containes approximately 60% alanine.The antifreeze protein could be detected in this fish's serum in winter but not in summer.The mRNT was isolated from the liver,and northern hybridization was processed using the cloned freeze gene as a probe.The results shown that the antifreeze protein was a protein regulated at the trans-criptional level.This study is important to the cloning of antifreeze gene,and also for the research of antifreeze gene expression in eukaryotic cells.