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Abstract Designing protein-binding proteins is critical for drug discovery. However, artificial-intelligence-based design of such proteins is challenging due to the complexity of protein–ligand interactions, the flexibility of ligand molecules and amino acid side chains, and sequence–structure dependencies. We introduce PocketGen, a deep generative model that produces residue sequence and atomic structure of the protein regions in which ligand interactions occur. PocketGen promotes consistency between protein sequence and structure by using a graph transformer for structural encoding and a sequence refinement module based on a protein language model. The graph transformer captures interactions at multiple scales, including atom, residue and ligand levels. For sequence refinement, PocketGen integrates a structural adapter into the protein language model, ensuring that structure-based predictions align with sequence-based predictions. PocketGen can generate high-fidelity protein pockets with enhanced binding affinity and structural validity. It operates ten times faster than physics-based methods and achieves a 97% success rate, defined as the percentage of generated pockets with higher binding affinity than reference pockets. Additionally, it attains an amino acid recovery rate exceeding 63%.
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Protein dynamics govern the oxyferrous state lifetime of an artificial oxygen transport protein
It has long been known that the alteration of protein side chains that occlude or expose the heme cofactor to water can greatly affect the stability of the oxyferrous heme state. Here, we demonstrate that the rate of dynamically driven water penetration into the core of an artificial oxygen transport protein also correlates with oxyferrous state lifetime by reducing global dynamics, without altering the structure of the active site, via the simple linking of the two monomers in a homodimeric artificial oxygen transport protein using a glycine-rich loop. The tethering of these two helices does not significantly affect the active site structure, pentacoordinate heme-binding affinity, reduction potential, or gaseous ligand affinity. It does, however, significantly reduce the hydration of the protein core, as demonstrated by resonance Raman spectroscopy, backbone amide hydrogen exchange, and pKa shifts in buried histidine side chains. This further destabilizes the charge-buried entatic state and nearly triples the oxyferrous state lifetime. These data are the first direct evidence that dynamically driven water penetration is a rate-limiting step in the oxidation of these complexes. It furthermore demonstrates that structural rigidity that limits water penetration is a critical design feature in metalloenzyme construction and provides an explanation for both the failures and successes of earlier attempts to create oxygen-binding proteins.
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- Award ID(s):
- 2025200
- PAR ID:
- 10488888
- Editor(s):
- Bernd Reif
- Publisher / Repository:
- Science Direct
- Date Published:
- Journal Name:
- Biophysical Journal
- Volume:
- 122
- Issue:
- 22
- ISSN:
- 0006-3495
- Page Range / eLocation ID:
- 4440 to 4450
- Subject(s) / Keyword(s):
- oxyferrous state protein design protein dynamics heme protein oxygen binding
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.bpj.2023.10.022
