Gulati S, Paliwal V K, Sharma M, Gill K D, Nath R
Toxicology. 1987 Jul;45(1):53-64. doi: 10.1016/0300-483x(87)90114-4.
A cadmium-binding protein from monkey brain has been isolated, purified and characterized. The absorption spectrum of this protein indicates the presence of Cu-Zn thionein in the normal monkey brain which has a strong affinity to bind cadmium. On cadmium exposure the protein sequestered most of the cadmium which entered the brain. The apparent molecular weight of this protein as determined on a gel filtration column calibrated with marker proteins has been found to be in the range of 11,500-12,000 Da. The ratio of absorbance at 254 nm/280 nm is more than 1 indicating the presence of cadmium-mercaptide bonds, which was further confirmed by the presence of 15 cysteine residues. Polyacrylamide gel electrophoresis of the protein shows 3 bands indicating the presence of 3 isometallothionein forms. Unlike hepatic or renal thioneins, the cadmium-binding protein in brain is not inducible following administration of cadmium. However, when antibodies raised against hepatic metallothionein were cross-reacted with brain Cd-binding protein, a line of identity was observed, indicating the 2 proteins are immunologically identical and share a high degree of structural similarity.
一种来自猴脑的镉结合蛋白已被分离、纯化和鉴定。该蛋白的吸收光谱表明，正常猴脑中存在铜锌硫蛋白，其对镉具有很强的结合亲和力。在接触镉时，该蛋白会螯合进入大脑的大部分镉。经用标记蛋白校准的凝胶过滤柱测定，该蛋白的表观分子量在11,500 - 12,000道尔顿范围内。254nm/280nm处的吸光度比值大于1，表明存在镉硫醇键，15个半胱氨酸残基的存在进一步证实了这一点。该蛋白的聚丙烯酰胺凝胶电泳显示有3条带，表明存在3种异金属硫蛋白形式。与肝或肾中的硫蛋白不同，脑内的镉结合蛋白在给予镉后不会被诱导。然而，当用针对肝金属硫蛋白产生的抗体与脑镉结合蛋白进行交叉反应时，观察到一条同一线，表明这两种蛋白在免疫上是相同的，并且具有高度的结构相似性。
