RT Journal Article SR Electronic T1 Salicylaldehyde ester-mediated protein semi-synthesis enables studies on the tetra-acetylation of HMGB1 JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.10.05.463167 DO 10.1101/2021.10.05.463167 A1 Tongyao Wei A1 Jiamei Liu A1 Yi Tan A1 Ruohan Wei A1 Jinzheng Wang A1 Hongxiang Wu A1 Yubo Tang A1 Xuechen Li YR 2021 UL http://biorxiv.org/content/early/2021/10/06/2021.10.05.463167.abstract AB To answer how protein post-translational modifications (PTMs) affect protein function, conformation, stability, localization and interaction with binders remains important in the biological study. However, the related study has been dramatically hindered by the difficulty in obtaining homogenous proteins with site-specific PTMs of interest. Herein, we introduce a protein semi-synthesis strategy via salicylaldehyde ester-mediated chemical ligations (Ser/Thr ligation and Cys/Pen ligation). This methodology has enabled us to generate Lys (2/6/7/11) tetra-acetylated HMGB1 (high-mobility group box 1) protein, a 25 kDa proinflammatory protein, in high purity. Further studies revealed that the tetra-acetylation may represent a regulatory switch to control the HMGB1 signaling pathway by abolishing its interaction with lipopoly-saccharide (LPS) and accelerating its degradation, consequently preventing cells from pyroptosis and lethality upon infectious injury.Competing Interest StatementThe authors have declared no competing interest.