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Holger Gohlke

Publications and source records attributed to Holger Gohlke.

4 recordsLinked to original sources

OneProt: Towards Multi-Modal Protein Foundation Models

Recent advances in Artificial Intelligence have enabled multi-modal systems to model and translate diverse information spaces. Extending beyond text and vision, we introduce OneProt, a multi-modal AI for proteins that integrates structural, sequence, text, and binding site data. Using the ImageBind framework, OneProt aligns the latent spaces of protein modality encoders in a lightweight fine-tuning scheme that focuses on pairwise alignment with sequence data rather than requiring full matches. This novel approach comprises a mix of Graph Neural Networks and transformer architectures. It demonstrates strong performance in retrieval tasks and showcases the efficacy of multi-modal systems in Protein Machine Learning through a broad spectrum of downstream baselines, including enzyme function prediction and binding site analysis. Furthermore, OneProt enables the transfer of representational information from specialized encoders to the sequence encoder, enhancing capabilities for distinguishing evolutionarily related and unrelated sequences and exhibiting representational properties where evolutionarily related proteins align in similar directions within the latent space. In addition, we extensively investigate modality ablations to identify the encoders that contribute most to predictive performance, highlighting the significance of the binding site encoder, which has not been used in similar models previously. This work expands the horizons of multi-modal protein models, paving the way for transformative applications in drug discovery, biocatalytic reaction planning, and protein engineering.

cs.LG

Integrative dynamic structural biology unveils conformers essential for the oligomerization of a large GTPase

Guanylate binding proteins (GBPs) are soluble dynamin-like proteins with structured domains that undergo a conformational transition for GTP-controlled oligomerization to exert their function as part of the innate immune system of mammalian cells - attacking intra-cellular parasites by disrupting their membranes. The structural basis and mechanism of this process is unknown. Therefore, we apply neutron spin echo, X-ray scattering, fluorescence, and EPR spectroscopy as techniques for integrative dynamic structural biology to human GBP1 (hGBP1). We mapped hGBP1's essential dynamics from nanoseconds to milliseconds by motional spectra of sub-domains. We find a GTP-independent flexibility of the C-terminal effector domain in the $μ$s-regime and structurally characterize conformers being essential that hGBP1 can open like a pocketknife for oligomerization. This unveils the intrinsic flexibility, a GTP-triggered association of the GTPase-domains and assembly-dependent GTP-hydrolysis as functional design principles of hGBP1 that control its reversible oligomerization in polar assemblies and the subsequent formation of condensates.

physics.bio-ph

Automated and optimally FRET-assisted structural modeling

FRET experiments can yield state-specific structural information on complex dynamic biomolecular assemblies. However, FRET experiments need to be combined with computer simulations to overcome their sparsity. We introduce (i) an automated FRET experiment design tool determining optimal FRET pairs for structural modeling, (ii) a protocol for efficient FRET-assisted computational structural modeling at multiple scales, and (iii) a quantitative quality estimate for judging the accuracy of determined structures. We tested against simulated and experimental data.

q-bio.QM

Resolving dynamics and function of transient states in single enzyme molecules

We used a hybrid fluorescence spectroscopic toolkit to monitor T4 Lysozyme (T4L) in action. By unraveling the kinetic and dynamic interplay of the conformational states, we sought to elucidate the dynamic structural biology of T4L. In particular, by combining single-molecule and ensemble multiparameter fluorescence detection, EPR spectroscopy, mutagenesis, and FRET-positioning and screening, we characterized three short-lived conformational states within the conformational landscape of the T4L over the ns-ms timescale. The use of 33 FRET-derived distance sets, to screen known T4L structures, revealed that T4L in solution mainly adopts the known open and closed states in exchange at 4 $μ$s. A newly found minor state, undisclosed by at present more than 500 crystal structures of T4L and sampled at 230 $μ$s, may be actively involved in the product release step in catalysis. The presented fluorescence spectroscopic toolkit is anticipated to accelerate the development of dynamic structural biology.

q-bio.BM