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Updated: Jul 8, 2026

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Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins
Published on: July 8, 2025
FLOWR.ROOT - A flow matching-based foundation model for joint multi-purpose structure-aware 3D ligand generation and
Julian Cremer1, Tuan Le2, Mohammad M Ghahremanpour3
1Machine Learning & Computational Sciences, Pfizer Worldwide R&D, Berlin, Germany. jn.cremer@icloud.com.
Nature Communications
|July 6, 2026
Summary
FLOWR.ROOT is a new AI model for drug discovery. It generates 3D molecules and predicts their binding affinity, streamlining the design of new medicines.
Area of Science:
- Computational chemistry
- Artificial intelligence in drug discovery
- Molecular modeling
Background:
- De novo drug design requires accurate prediction of ligand-target interactions.
- Existing methods often lack the ability to unify ligand generation and binding affinity prediction.
- The development of foundation models offers a promising avenue for integrated molecular design.
Purpose of the Study:
- To introduce FLOWR.ROOT, a unified SE(3)-equivariant flow-matching foundation model.
- To enable pocket-aware 3D ligand generation and multi-endpoint binding affinity prediction.
- To provide pLDDT-based confidence estimation within a single framework.
Main Methods:
- Utilizing SE(3)-equivariant flow matching for molecular generation.
- Implementing a mixed isotropic-anisotropic prior placement strategy for diverse sampling.
- Employing a three-stage training process: large-scale pre-training, refinement on co-crystal data, and LoRA finetuning.
- Integrating joint structure-affinity modeling for inference-time guidance.
Main Results:
- FLOWR.ROOT supports various generative tasks: pocket-conditional generation, interaction- and pharmacophore-conditional sampling, scaffold hopping, fragment growing/replacement.
- The model achieves accurate binding affinity prediction (pIC50, pKi, pKd, pEC50) and confidence estimation (pLDDT).
- Joint structure-affinity modeling allows for inference-time importance-sampling guidance without external scoring functions.
Conclusions:
- FLOWR.ROOT successfully unifies 3D ligand generation and binding affinity prediction in a single foundation model.
- The model demonstrates versatility across multiple drug design tasks, from hit identification to lead optimization.
- Case studies on kinase selectivity and scaffold elaboration highlight the practical utility of FLOWR.ROOT in accelerating drug discovery pipelines.
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