Show Notes
Avery NG et al., PNAS - This episode covers a PNAS study reporting the de novo design of miniprotein inhibitors targeting porcine deltacoronavirus (PDCoV). The lead minibinder, MB11, binds the PDCoV RBD with picomolar affinity, broadly neutralizes diverse deltacoronaviruses, and resists multiple biochemical stresses. Key terms: Porcine deltacoronavirus, miniprotein inhibitor, MB11, protein design, neutralization.
Study Highlights:
Researchers used computational design (BindCraft and AlphaFold3) to generate miniprotein inhibitors targeting the PDCoV receptor-binding domain and screened candidates by BLI and pseudovirus neutralization. MB11 binds the PDCoV RBD with KD ~155 pM and neutralizes PDCoV and several distantly related DCoVs with superior potency to known antibodies. Cryo-EM shows MB11 occludes receptor-binding loops and sterically blocks APN engagement, explaining broad neutralization. Deep mutational scanning indicates a high barrier to escape and biochemical tests show MB11 retains function after high temperature and low pH exposure but is susceptible to pepsin.
Conclusion:
MB11 is a promising preclinical PDCoV inhibitor combining ultrapotent, broad neutralization, mechanistic receptor blockade, and favorable stability, supporting further development for pandemic preparedness.
Music:
Enjoy the music based on this article at the end of the episode.
Article title:
Computational design of an ultrapotent deltacoronavirus miniprotein inhibitor
First author:
Avery NG
Journal:
PNAS
DOI:
10.1073/pnas.2533456123
Reference:
Avery NG, Yoshiyama CN, Taylor AL, Park Y-J, Asarnow D, Perruzza L, Brown JT, Corti D, Benigni F, Starr TN, Veesler D. Computational design of an ultrapotent deltacoronavirus miniprotein inhibitor. PNAS. 2026;123:e2533456123. doi:10.1073/pnas.2533456123
License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/
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Episode link: https://basebybase.com/episodes/mb11-pdcoronavirus-minibinder
QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-05-06.
QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the sections covering MB11 design (BindCraft/AF3), binding measurements (BLI), neutralization assays (PDCoV and related DCoVs), cryo-EM structural validation, deep mutational scanning escape analysis, biophysical stability tests (heat/acid/enzymes), and delivery/manufacturing implications discussed.
- transcript topics: Computational minibinder design (BindCraft and AlphaFold3); Biolayer interferometry binding screening; Pseudovirus neutralization assays and breadth across DCoVs; Cryo-EM structure and mechanism of entry inhibition; Deep mutational scanning and viral escape barriers; Biophysical stability under heat, low pH, and proteases
QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0
Metadata Audited:
- article_doi
- article_title
- article_journal
- license
Factual Items Audited:
- MB11 has KD ≈ 155 pM to PDCoV RBD (binds with high affinity).
- MB11 neutralizes PDCoV pseudovirus with IC50 ≈ 216 pM.
- MB11 shows broad neutralization across DCoVs, including SparrowCoVISU42824 (IC50 ≈ 14 pM) and MuniaCoVHKU13 (IC50 ≈ 152 nM).
- Cryo-EM reveals MB11 wedges into PDCoV RBD receptor-binding loops, blocking APN engagement; structure at 2.8 Å resolution with AF3 predicted model within ~0.6 Å RMSD.
- Deep mutational scanning shows a high barrier to escape; only a few mutations (at residues such as Y394 and V395) can modestly affect binding without severely compromising APN affi
- MB11 remains functional after heating to 70 °C for 1 h and after exposure to pH 2.2; largely resistant to proteases (except pepsin) and not aggregated after stress.
QC result: Pass.
