The development of bioconjugation chemistry has enabled the combination of various synthetic functionalities to proteins, giving rise to new classes of protein conjugates with functions well beyond what Nature can provide. Despite the progress in bioconjugation chemistry, there are no reagents developed to date where the reactivity can be tuned in a user-defined fashion to address different amino acid residues in proteins. Here, we report that 2-chloromethyl acryl reagents can serve as a simple yet versatile platform for selective protein modification at cysteine or disulfide sites by tuning their inherent electronic properties through the amide or ester linkage. Specifically, the 2-chloromethyl derivatives (acrylamide or acrylate) can be obtained via a simple and easily implemented one-pot reaction based on the coupling reaction between commercially available starting materials with different end-group functionalities (amino group or hydroxyl group). 2-Chloromethyl acrylamide reagents with an amide linkage favor selective modification at the cysteine site with fast reaction kinetics and near quantitative conversations. In contrast, 2-chloromethyl acrylate reagents bearing an ester linkage can undergo two successive Michael reactions, allowing the selective modification of disulfides bonds with high labeling efficiency and good conjugate stability.

中文翻译：

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通过氯甲基丙烯酸试剂中的单原子取代化学选择性半胱氨酸或二硫化物修饰

生物偶联化学的发展使各种合成功能与蛋白质相结合，产生了新类别的蛋白质偶联物，其功能远远超出了大自然所能提供的。尽管生物偶联化学取得了进展，但迄今为止还没有开发出可以以用户定义的方式调整反应性以解决蛋白质中不同氨基酸残基的试剂。在这里，我们报告说 2-氯甲基丙烯酸试剂可以作为一个简单而通用的平台，通过酰胺或酯键调整其固有的电子特性，在半胱氨酸或二硫键位点进行选择性蛋白质修饰。具体而言，2-氯衍生物（丙烯酰胺或丙烯酸酯）可以得到通过基于具有不同端基官能团（氨基或羟基）的市售原料之间的偶联反应，简单且易于实施的一锅法反应。具有酰胺键的 2-氯甲基丙烯酰胺试剂有利于在半胱氨酸位点进行选择性修饰，具有快速反应动力学和接近定量的对话。相比之下，带有酯键的 2-氯甲基丙烯酸酯试剂可以进行两个连续的迈克尔反应，允许选择性修饰二硫键，具有高标记效率和良好的共轭稳定性。