2. Academic Validation
  3. Discovery of 2-Chloro-pyrrolo[2,3- d]pyrimidin-4-one Derivatives as Protein Disulfide Isomerase Inhibitors with a Novel Allosteric-Covalent Binding Mode and Anti-Glioblastoma Activity

Discovery of 2-Chloro-pyrrolo[2,3- d]pyrimidin-4-one Derivatives as Protein Disulfide Isomerase Inhibitors with a Novel Allosteric-Covalent Binding Mode and Anti-Glioblastoma Activity

  • J Med Chem. 2026 Feb 12;69(3):3148-3175. doi: 10.1021/acs.jmedchem.5c03058.
Qiulin Zhang 1,  Haiwen Lin 2,  Jiafan Yuan 1,  Shi-Peng Zhang 3,  Haotian Wang 1,  Hanjie Hu 4,  Jingyi Wang 1,  Xiaofei Wang 1,  Zhaofa Wu 1,  Shi-Chao Lu 3,  Youwei Ai 1,  Bo Yan 1 5
Affiliations

Affiliations

  • 1 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
  • 2 College of Life Science, Yunnan University, Kunming 650091, China.
  • 3 State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
  • 4 Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
  • 5 Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
PMID: 41574754 DOI: 10.1021/acs.jmedchem.5c03058
Abstract

Protein disulfide isomerase (PDI) is an endoplasmic reticulum oxidoreductase/chaperone, and its dysregulation contributes to Cancer progression, particularly glioblastoma. A high-throughput screen identified TC8026 as a PDI-active hit, and further optimization afforded a pyrrolo[2,3-d]pyrimidin-4-one series with up to 20-fold improved potency. Representative analogues (30w, 30z, 30aa, and 30ab) potently inhibited PDI, induced endoplasmic reticulum stress-mediated Apoptosis in glioblastoma cells, and 30z significantly suppressed tumor growth in a U251 xenograft model. Mechanistic studies revealed a previously unrecognized allosteric-covalent binding mode. The inhibitors initially engage an allosteric pocket within the b' domain involving residues H256 and F304, thereby perturbing the substrate-binding interface and inducing conformational changes that expose the noncatalytic cysteine C312 for covalent capture. This b'-directed allosteric covalency, distinct from conventional catalytic cysteine modification, confers enhanced selectivity within the PDI family. These findings define a novel allosteric-covalent chemotype of PDI inhibitors with a unique binding mechanism and promising antiglioblastoma potential.

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