Covalently Engineered Nanobody Chimeras for Targeted Membrane Protein Degradation

• DOI: 10.1021/jacs.1c08521
• Publication Date: 2021-10-01T17:22:52Z
• Authors: Heng Zhang; Yu Han; Yuanfan Yang; Feng Lin; Kexin Li; Linghao Kong; Hongxiang Liu; Yongjun Dang; Jian Lin; Peng R. Chen
• Keywords: 0303 health sciences; 03 medical and health sciences; Cell Line, Tumor; Proteolysis; Humans; Membrane Proteins; Cell-Penetrating Peptides; Single-Domain Antibodies; Protein Engineering; B7-H1 Antigen

The targeted degradation of membrane proteins would afford an attractive and general strategy for treating various diseases that remain difficult with the current proteolysis-targeting chimera (PROTAC) methodology. We herein report a covalent nanobody-based PROTAC strategy, termed GlueTAC, for targeted membrane protein degradation with high specificity and efficiency. We first established a mass-spectrometry-based screening platform for the rapid development of a covalent nanobody (GlueBody) that allowed proximity-enabled cross-linking with surface antigens on cancer cells. By conjugation with a cell-penetrating peptide and a lysosomal-sorting sequence, the resulting GlueTAC chimera triggered the internalization and degradation of programmed death-ligand 1 (PD-L1), which provides a new avenue to target and degrade cell-surface proteins.