Selection of mutant µplasmin for amyloid-β cleavage in vivo

Dongying Yang, Wei Zhu, Yingjie Wang, Fangmei Tan, Zhiping Ma, Jiali Gao, Xinli Lin

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


One of the main culprits of Alzheimer’s disease (AD) is the formation of toxic amyloid-β (Aβ) peptide polymers and the aggregation of Aβ to form plaques in the brain. We have developed techniques to purify the catalytic domain of plasmin, micro-plasmin (µPlm), which can be used for an Aβ-clearance based AD therapy. However, in serum, µPlm is irreversibly inhibited by its principal inhibitor α2-antiplasmin (α2-AP). In this study, we engineered and selected mutant forms of µPlm that are both catalytically active and insensitive to α2-AP inhibition. We identified surface residues of μPlm that might interact and bind α2-AP, and used an alanine-scanning mutagenesis method to select residues having higher activity but lower α2-AP inhibition. Then we employed saturation mutagenesis for further optimize both properties. Modeled complex structure of µPlm/α2-AP shows that F587 is a critical contact residue, which can be used as a starting position for further investigation.

Original languageEnglish (US)
Article number12117
JournalScientific reports
Issue number1
StatePublished - Jul 21 2020

Bibliographical note

Funding Information:
This work was supported in part by the Natural Science Foundation of Shandong Province (ZR2017LC017), National Natural Science Foundation (30901023), and Shenzhen Municipal Science and Technology Innovation Commission (KQTD2017-0330155106581).

Publisher Copyright:
© 2020, The Author(s).


  • Amyloid beta-Peptides/metabolism
  • Animals
  • Binding Sites
  • Catalytic Domain
  • Humans
  • Mice
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Mutation
  • Peptide Fragments/chemistry
  • Plasminogen/chemistry
  • Protein Conformation
  • alpha-2-Antiplasmin/metabolism

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't


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