Acidic residues (Asp and Glu) have a high prevalence on protein surfaces, but cross-linking reactions targeting these residues are limited. Existing methods either require high-concentration coupling reagents or have low structural compatibility. Here we extended our previously reported “plant-and-cast” strategy to develop two heterobifunctional cross-linkers DE1 and OPAAZ. These cross-linking reaction proceeds at neutral pH and room temperature without coupling reagents.