[Study on the form and stability of alpha and beta domain of metallothionein binding to lead (II)].
For studying the actions of metallothionein(MT) binding to lead, the alpha and beta structural domain of metallothionein binding to Cd (Cd7-alpha-MT and Cd7-beta-MT) was extracted and purified from a strain of BL2I by dissolving them in acid to eliminate protein. The apo-alpha-MT and apo-beta-MT were separated by gel Sephadex-G25 to eliminate Cd. Different doses of lead were added to the apo-alpha-MT and apo-beta-MT. The structure of MT metal Cluster with lead was formed after reacting completely, and was then examined by ultraviolet spectrophotometer. The UV spectrum showed that the interaction of lead with alpha domain leading to two kind of products, one binding with 4 lead(Pb4-alpha-MT) and the other binding with 7 lead (Pb7-alpha-MT). Only one product, the beta domain binding with 3 lead(Pb3-beta-MT) was formed. The reaction rate of these products with DTNB was also measured in this study. Results showed that the domain binding to 4 lead was more stable than the others. All these works provide strong evidence that further studies on the mechanism of MT interacting with lead and the function of MT in eliminating lead were needed.
Li
X
X
National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871, China.
Hao
S
S
Liu
Y
Y
Ru
B
B
D004347:Drug Interactions; D007854:Lead / Q000737:chemistry*; D008668:Metallothionein / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D007854:Lead; D008668:Metallothionein