99mTc labeling of proteins: initial evaluation of a novel diaminedithiol bifunctional chelating agent.
99mTc labeling of proteins: initial evaluation of a novel diaminedithiol bifunctional chelating agent.
复制标题
DOI：
--
复制
发表时间：
1990-02
期刊：
影响因子：
11.2
通讯作者：
K. Baidoo;U. Scheffel;S. Lever
中科院分区：
文献类型：
--
作者：
K. Baidoo;U. Scheffel;S. Lever
初步评价了一种新的硫代内酯双功能螯合剂，1，用于在温和条件下将二胺二硫醇（DADT）配体系统引入蛋白质上，随后用99 mTc标记。对于人血清白蛋白和单克隆抗结肠癌抗体（B72.3），在室温下在pH 7-9下实现时间依赖性偶联。偶联的蛋白质可以被标记在一个直接的方式（Sn 2 +/99 mTcO 4-）和交换标记（与预先形成的99 mTc-葡庚糖酸）在良好的到优异的产率在pH 7。相比之下，未修饰的蛋白质只能通过直接方法标记，最高产率为30%。标记的，偶联的蛋白质通过高效液相色谱法进行纯化，并发现在体外稳定超过20小时的研究期间，没有证据表明标签的损失。这种特殊的稳定性是由于DADT配体对99 mTc的螯合作用，因为直接标记的未修饰人血清白蛋白和未修饰抗体分别损失了66%（3.5 h）和47%（20 h）的标记物。在正常小鼠和家兔中的生物分布研究证实了99 mTc-DADT标记的蛋白质与99 mTc标记的未修饰蛋白质相比在体内的稳定性。因此，新型硫内酯1是一种有用的双功能螯合剂，用于将DADT配体系统引入到各种蛋白质上，用于随后在温和条件下掺入锝，使得所得标记产物在体外和体内稳定。
The initial evaluation of a novel thiolactone bifunctional chelating agent, 1, for facile introduction of the diaminedithiol (DADT) ligand system onto proteins for subsequent labeling with 99mTc under mild conditions is presented. For human serum albumin and a monoclonal anti-colon carcinoma antibody (B72.3), time-dependent coupling was achieved at pH 7-9 at room temperature. The coupled proteins could be labeled in a direct fashion (Sn2+/99mTcO4-) and by exchange labeling (with preformed 99mTc-glucoheptonate) in good to excellent yields at pH 7. In contrast, the unmodified proteins could be labeled only by direct methods with maximum yields of 30%. The labeled, coupled proteins were purified by high performance liquid chromatography and found to be stable in vitro over a 20-h period of study with no evidence for the loss of label. This exceptional stability is due to the chelation of 99mTc by the DADT ligand since 66% (3.5 h) and 47% (20 h) of the label were lost from directly labeled unmodified human serum albumin and the unmodified antibody, respectively. Biodistribution studies in normal mice and rabbits confirmed the stability of the 99mTc-DADT-labeled proteins compared to the 99mTc-labeled unmodified proteins in vivo. Thus, the novel thiolactone 1 is a useful bifunctional chelating agent for introducing the DADT ligand system onto a variety of proteins for subsequent incorporation of technetium under mild conditions such that the resultant labeled products are stable in vitro and in vivo.