Abstract
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 language | English (US) |
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Article number | 12117 |
Journal | Scientific reports |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - 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).
Keywords
- 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