2. Academic Validation
  3. A fragment integrational approach to GPCR inhibition: Identification of a high affinity small molecule CXCR4 antagonist

A fragment integrational approach to GPCR inhibition: Identification of a high affinity small molecule CXCR4 antagonist

  • Eur J Med Chem. 2022 Mar 5;231:114150. doi: 10.1016/j.ejmech.2022.114150.
Xiong Fang 1,  Qian Meng 1,  Huijun Zhang 2,  Xiao Fang 1,  Lina S Huang 3,  Xingquan Zhang 3,  Robert T Schooley 3,  Aaron Ciechanover 4,  Jing An 5,  Yan Xu 6,  Ziwei Huang 7
Affiliations

Affiliations

  • 1 Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
  • 2 Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China; Division of Infectious Diseases and Global Public Health, Department of Medicine, School of Medicine, University of California at San Diego, La Jolla, CA, 92037, USA.
  • 3 Division of Infectious Diseases and Global Public Health, Department of Medicine, School of Medicine, University of California at San Diego, La Jolla, CA, 92037, USA.
  • 4 The Rapport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, 3109601, Israel; Nobel Institute of Biomedicine, Zhuhai, 519080, China; Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, Chinese University of Hong Kong, Shenzhen, 518172, China.
  • 5 Division of Infectious Diseases and Global Public Health, Department of Medicine, School of Medicine, University of California at San Diego, La Jolla, CA, 92037, USA. Electronic address: jan@health.ucsd.edu.
  • 6 Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China; Nobel Institute of Biomedicine, Zhuhai, 519080, China; Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, Chinese University of Hong Kong, Shenzhen, 518172, China. Electronic address: yanxu@cuhk.edu.cn.
  • 7 Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China; Division of Infectious Diseases and Global Public Health, Department of Medicine, School of Medicine, University of California at San Diego, La Jolla, CA, 92037, USA; Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, Chinese University of Hong Kong, Shenzhen, 518172, China. Electronic address: zhuang@health.ucsd.edu.
PMID: 35124530 DOI: 10.1016/j.ejmech.2022.114150
Abstract

Targeting the protein-protein interactions involving CXCR4, a member of Chemokine Receptor family and G-protein-coupled receptor superfamily, has become an attractive therapeutic strategy for HIV-1 Infection, hematopoietic stem cell mobilization, and Cancer metastasis. As such, new small molecule CXCR4 antagonists are needed to offer therapeutic alternatives with enhanced clinical outcomes. Here, employing a fragment integrational approach we designed and synthesized a new and potent small molecule CXCR4 Antagonist (named as HF51116), as well as a fluorescent (FITC)-labeled HF51116 (FITC-HF51116). HF51116 exhibited very high CXCR4 binding affinity with IC50 of 12 nM in competitive binding with a CXCR4 specific antibody 12G5, which is comparable to the wild type chemokines or synthetic Peptides of much larger molecular sizes. Direct binding measurement using FITC-HF51116 further revealed the compound's high CXCR4 affinity. HF51116 strongly antagonized SDF-1α-induced cell migration, calcium mobilization, and CXCR4 internalization. Furthermore, HF51116 inhibited HIV-1 Infection via CXCR4, demonstrating its Antiviral therapeutic potential. The mechanism of HF51116-CXCR4 interaction was analyzed by site-directed mutagenesis and molecular modeling which suggested that the compound recognizes the minor and major subpockets of CXCR4. Its binding to CXCR4 was found to block G protein-dependent downstream signal pathways as detected by luciferase reporter assays. With its potent bioactivities and asymmetric structure amenable to chemical diversification, HF51116 may serve as a prototype for developing a new class of CXCR4-targeted therapeutics and proof of the concept of similar strategies for studying other GPCRs.

Keywords

Chemokine receptor CXCR4; Drug design; G protein coupled receptor; HIV infection; Protein-protein interaction; Small molecule antagonist.

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