1. Academic Validation
  2. Identification of 2-PMPA as a novel inhibitor of cytosolic carboxypeptidases

Identification of 2-PMPA as a novel inhibitor of cytosolic carboxypeptidases

  • Biochem Biophys Res Commun. 2020 Dec 17;533(4):1393-1399. doi: 10.1016/j.bbrc.2020.10.029.
Ruixue Wang 1 Lianyun Lin 1 Yiqiang Zheng 1 Peng Cao 2 Zhiguang Yuchi 3 Hui-Yuan Wu 4
Affiliations

Affiliations

  • 1 School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China.
  • 2 Key Laboratory of Drug Targets and Drug Leads for Degenerative Diseases, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
  • 3 School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China. Electronic address: yuchi@tju.edu.cn.
  • 4 School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China. Electronic address: huiyuan.wu@tju.edu.cn.
Abstract

Cytosolic carboxypeptidases (CCPs) comprise a unique subfamily of M14 carboxypeptidases and are erasers of the reversible protein posttranslational modification- polyglutamylation. Potent inhibitors for CCPs may serve as leading compounds targeting imbalanced polyglutamylation. However, no efficient CCP inhibitor has yet been reported. Here, we showed that 2-phosphonomethylpentanedioic acid (2-PMPA), a potent inhibitor of the distant M28 family member glutamate Carboxypeptidase II (GCPII), rather than the typical M14 inhibitor 2-benzylsuccinic acid, could efficiently inhibit CCP activities. 2-PMPA inhibited the recombinant Nna1 (a.k.a. CCP1) for hydrolyzing a synthetic peptide in a mixed manner, with Ki and Ki' being 0.11 μM and 0.24 μM respectively. It inhibited Nna1 for deglutamylating tubulin, the best-known polyglutamylated protein, with an IC50 of 0.21 mM. Homology modeling predicted that the R-form of 2-PMPA is more favorable to bind Nna1, unlike that GCPII prefers to S-form. This work for the first time identified a potent inhibitor for CCP family.

Keywords

2-PMPA; Cytosolic carboxypeptidase; Enzyme kinetics; Inhibitor; Polyglutamylation.

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