Lauffer R B, Brady T J
Magn Reson Imaging. 1985;3(1):11-6. doi: 10.1016/0730-725x(85)90004-9.
The proteins bovine serum albumin (BSA) and bovine immunoglobulin (IgG) have been labeled with paramagnetic gadolinium (III) and manganese (II) complexes using the bifunctional chelate approach. Diethylenetriaminepentaacetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA) were attached to several free amino groups on the proteins using cyclic anhydride forms of these ligands. The incorporation of the metal ions Gd+3 and Mn+2 into the chelating groups yielded highly paramagnetic proteins. The water relaxation ability (or relaxivity) of the protein-bound chelates at 20 MHz was found to be superior to that of the free metal complexes. Differences in relaxivity between the DTPA and EDTA conjugates could largely be accounted for by differences in the metal ion exposure to water. This labeling technique can be used in the preparation of intravascular NMR contrast agents (like paramagnetically-labeled human serum albumin) or target-specific agents (labeled monoclonal antibodies or fibrinogen).
已使用双功能螯合方法，用顺磁性钆（III）和锰（II）配合物标记了蛋白质牛血清白蛋白（BSA）和牛免疫球蛋白（IgG）。使用这些配体的环状酸酐形式，将二乙烯三胺五乙酸（DTPA）和乙二胺四乙酸（EDTA）连接到蛋白质上的几个游离氨基上。将金属离子Gd + 3和Mn + 2掺入螯合基团中，得到了高顺磁性蛋白质。发现在20 MHz时，与蛋白质结合的螯合物的水弛豫能力（或弛豫率）优于游离金属配合物。DTPA和EDTA共轭物之间弛豫率的差异在很大程度上可由金属离子与水接触的差异来解释。这种标记技术可用于制备血管内NMR造影剂（如顺磁性标记的人血清白蛋白）或靶向特异性试剂（标记的单克隆抗体或纤维蛋白原）。
