论文部分内容阅读
金属硫蛋白(MT)是一类广泛分布、富含半胱氨酸,可结合金属的低分子量非酶蛋白质。它在金属中毒、微量元素代谢调节和抗射线、自由基损伤等方面有重要作用。本研究提纯了兔肝MT_1和MT_2(rlMT_1、rlMT_2)。方法是:先给家兔多次皮下注射CdCl_2诱导MT合成,之后取肝作匀浆,经冷乙醇提取制得MT粗提液。该粗提液通过Sepbaclx G—50 柱(4.5×95cm)和DEAE-cellulose DE52 柱(2.5×4cm)层析,使分离出rlMT_1和rlMT_2两种亚型。鉴定表明,rlMT_1和rlMT_2的分子量均约14KD,纯度为SDS—PAGE分析呈单一条带,与Sigma标准品的分子量和纯度一致。氨基酸组成中,半胱氨酸和硫基含量都接近每分子20个,不含芳香族氨基酸和组氨酸。本次研究为探寻MT检测工作,推动我国MT的研究奠定了良好基础。
Metallothionein (MT) is a class of widely distributed, cysteine-rich, low-molecular-weight, non-enzymatic proteins that bind to metals. It plays an important role in metal poisoning, trace element metabolism regulation, anti-radiation and free radical damage. In this study, rabbit liver MT_1 and MT_2 (rlMT_1, rlMT_2) were purified. The method is as follows: First, multiple subcutaneous injections of CdCl 2 are given to rabbits to induce MT synthesis, and then the liver is taken for homogenization, and the crude MT extract is obtained by cold ethanol extraction. The crude extract was chromatographed on a Sepbaclx G-50 column (4.5 x 95 cm) and a DEAE-cellulose DE52 column (2.5 x 4 cm) to isolate both the rlMT_1 and rlMT_2 subtypes. Identification showed that the molecular weight of rlMT_1 and rlMT_2 were about 14KD, the purity of the single band was SDS-PAGE analysis, consistent with the Sigma standard molecular weight and purity. Amino acid composition, cysteine and sulfur content are close to 20 molecules per molecule, does not contain aromatic amino acids and histidine. This study lays a good foundation for exploring MT testing work and promoting MT research in our country.