istegrate (DIN) Theory Enabling Precision Engineering of Proteins

Chemical technology principles for selective bioconjugation of proteins and antibodies

Proteins are multifunctional large organic compounds that constitute an essential component of a living system. Hence, control over their bioconjugation impacts science at the chemistry-biology-medicine interface. A chemical toolbox for their precision engineering can boost healthcare and open a gateway for directed or precision therapeutics. Such a chemical toolbox remained elusive for a long time due to the complexity presented by the large pool of functional groups. The precise single-site modification of a protein requires a method to address a combination of selectivity attributes. This review focuses on guiding principles that can segregate them to simplify the task for a chemical method. Such a disintegration systematically employs a multi-step chemical transformation to deconvolute the selectivity challenges. It constitutes a disintegrate (DIN) theory that offers additional control parameters for tuning precision in protein bioconjugation. This review outlines the selectivity hurdles faced by chemical methods. It elaborates on the developments in the perspective of DIN theory to demonstrate simultaneous regulation of reactivity, chemoselectivity, site-selectivity, modularity, residue specificity, and protein specificity. It discusses the progress of such methods to construct protein and antibody conjugates for biologics, including antibody-fluorophore and antibody-drug conjugates (AFCs and ADCs). It also briefs how this knowledge can assist in developing small molecule-based covalent inhibitors. In the process, it highlights an opportunity for hypothesis-driven routes to accelerate discoveries of selective methods and establish new targetome in the precision engineering of proteins and antibodies.

Protein-Protein Interaction in Multicomponent Reaction Enables Chemoselective, Site-Selective, and Modular Labeling of Native Proteins

A protein's pool of functionalities presents a formidable challenge for its single-site modification. Here, we report a method to harness protein-protein interaction (PPI) to drive selective modification. It involves the chemoselective reversible generation of reactive intermediates and utilizes PPI-specificity to drive the subsequent site-selective irreversible step. The disintegrate (DIN) theory-driven multicomponent aza-Morita-Baylis-Hillman (aza-MBH) reaction offers homogeneous and modular single-site protein modification capable of late-stage mono- and dual-probe installation.