1. Academic Validation
  2. Met343Val mutation disrupts the shuttling of Trp380 leading to a low-activity conformer of activated protein C and causes thrombosis

Met343Val mutation disrupts the shuttling of Trp380 leading to a low-activity conformer of activated protein C and causes thrombosis

  • J Thromb Haemost. 2024 May 22:S1538-7836(24)00295-2. doi: 10.1016/j.jtha.2024.05.012.
Shijie Zhou 1 Fang Li 2 Zhe Lai 1 Xi Wu 1 Junwei Yuan 3 Wenman Wu 1 Qiulan Ding 1 Xuefeng Wang 1 Jing Dai 4 Qin Xu 5 Yeling Lu 6
Affiliations

Affiliations

  • 1 Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
  • 2 State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
  • 3 Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine.
  • 4 Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: dj40572@rjh.com.cn.
  • 5 State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China. Electronic address: xuqin523@sjtu.edu.cn.
  • 6 Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: yeling-lu@shsmu.edu.cn.
Abstract

Background: Protein C (PC) pathway serves as a major defense mechanism against thrombosis by the activation of PC through the thrombin-thrombomodulin (TM) complex and subsequent inactivation of the activated factor V (FVa) and Factor VIII (FVIIIa) with the assistance of protein S, thereby contributing to hemostatic balance. We identified two unrelated patients who suffered from recurrent thrombosis and carried the same heterozygous mutation c.1153A>G, p. Met343Val (M343V) in PROC gene. This mutation had not been previously reported.

Objectives: To explore the molecular basis underlying the anticoagulant defect in patients carrying the M343V mutation in PROC.

Methods: We expressed PC-M343V variant in mammalian cells and characterized its properties through coagulation assays.

Results: Our findings demonstrated that while activation of mutant zymogen by thrombin-TM was slightly affected, cleavage of chromogenic substrate by APC-M343V was significantly impaired. However, CA2+ increased the cleavage efficiency by approximately 50%. Additionally, there was a severe reduction in affinity between APC-M343V and Na+. Furthermore, the inhibitory ability of APC-M343V towards FVa was markedly impaired. Structural and simulation analyses suggested that Val343 might disrupt the potential hydrogen bonds with Trp380 and cause Trp380 to orient closer to His211, potentially interfering with substrate binding and destabilizing the catalytic triad of APC.

Conclusion: The M343V mutation in patients adversely affects the reactivity and/or folding of the active site as well as the binding of the physiological substrate to the Protease, resulting in impaired protein C anticoagulant activity, ultimately leading to thrombosis.

Keywords

anticoagulant; mutation; protein C; thrombosis.

Figures
Products
Inhibitors & Agonists
Other Products